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Mechanical Engineering is a branch of engineering that applies principles of physics, materials science, and mathematics to design, analyze, manufacture, and maintain mechanical systems. It encompasses a wide range of activities, including the development of machinery, tools, and thermal systems, focusing on efficiency, performance, and sustainability.
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FUNDAMENTALS OF ENGINEERING THERMODYNAMICS Eighth Edition
by Juan Martin and 
1 more
Margaret Bailey
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Solucionario - Diseño en Ingeniería Mecánica - Shigley
by Paola Beltran
-12, fundamental deviation δ F = +0.043 mm. From Eq. (2-40) d min = d + δ F = 45.000 + 0.043 = 45.043 mm Ans. d max = d + δ F + d = 45.000 + 0.043 + 0.016 = 45.059 mm Ans. 2-30 Choose 50 mm as basic size. From Table 2-8 fit is 50H7/g6.... more
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Cambridge-international-as-and-a-level-physics-coursebook-second-edition-part-one web (1)
by Arash Dashti
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Material science complete notes B.tech 2nd year Mechanical by Kapil kumar
by HARISH BHATIA
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Solving Problems in Food Engineering
by carlos andres
except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known... more
1) Overall mass balance und then the slush is separated in a centrifugal separator into ice crystals ind concentrated juice. An amount of 500 kg/h of liquid is recycled from the separator to the freezer. Calculate the amount of ice that is removed in the separator and the amount of concentrated juice produced. Assume steady state. From eqn (3.8) find J=250 kg/h and then from eqn (3.7) find I= 750 kg/h.
A liquid food at 50 °C is being pumped at a rate of 3 m°/h from a tank A, where the absolute pressure is 12350 Pa, to a tank B, where the absolute pressure is 101325 Pa, through a sanitary pipe 1.5 in nominal diameter with 4.6 x 10-°m surface roughness . The pump is | m below the liquid level in tank A and the discharge in tank B is 3.3 m above the pump. If the length of the pipe in the suction line is 2 m, the discharge line 10 m, and there are one 90° elbow in the suction line, two 90 ° elbows in the discharge line, and one globe valve in the discharge line, calculate the power required, the developed head, and the avail- able Net Positive Suction Head (NPSH). Which of the three pumps that have the characteristic curves given below could be used for this pumping job? The viscosity and the density of the liquid are 0.003 mPas and 1033 kg/m? respec- tively. The efficiency of the pump is 65%. Assume that the level in tank A is constant.
Develop a spreadsheet program to plot the temperature distribution in a plane wall of 4 cm thickness and inner wall surface temperature of 200 °C, at steady state, when a) the thermal conductivity of the wall in W/m °C varies according to the equation k = 0.0325+0.0004T and 250 W/m? of heat are transferred through the wall; and b) the thermal conductivity is constant and equal to the average value for the temperature range of the wall calculated in case a. Calculate the heat transfer rate in case b and compare it to the heat transfer rate of case a.
The physical properties must be calculated at the average water temperature:
Calculate the amount of dry solid per unit surface area:
A liquid food is heated in an unbaffled agitated vessel with a heating jacket. The inside diameter of the vessel is 1 m and the diameter of the flat-bladed paddle agitator is 30 cm. The agitator rotates at N = 60rpm. Calculate the heat transfe1 coefficient at the wall of the jacket. Assume the following physical properties fo1 the liquid food: density 1030 kg/m®, viscosity at the bulk liquid temperature 1.5 mPas, viscosity at the wall temperature 1 mPas, heat capacity 4kl/kg °C. thermal conductivity 0.6W/m°C. The following correlation can be used fot this case. Calculate the Re number (take care with the units):
a Calculate the overall heat transfer coefficient based on the outside surface area of the pipe:
Draw the process diagram: Step 2 Step |
A 211x300 can containing a meat product is heated in a retort. The initial temperature of the can is 50°C, the heat transfer coefficient at the surface is 3000W j m*°C, and the physical properties of the meat product are: k = 0.5W/m°C, cy = 2.85kJ/m°C, and p = 1100kg/m>. Calculate the tem- perature at the geometric center of the can after 30 min if the steam temperature in the retort is 130°C.
that the fruit is spherical; its initial temperature is 25°C; the cold water and the air temperature are 1°C; the diameter of the fruit is 6 cm; the heat transfer coefficient is 1000W / m?°C in the case of hydrocooling, 20W / m? °C in the case of forced air cooling, and 5W/m?°C in the case of room cooling; and the physical properties of the fruit are: k=0.4W/m°C, p= 900kg/m’, Cp = 3.5kI/kg °C. The product development department in a food plant is interested in knowing what shape they should give to a new product for a faster temperature change at the center of the product from 20°C to 90°C. Should the shape be a cube 50mm x 50mm x 50mm, a cylinder with diameter 62.035 mm and length 41.36 mm, or a sphere with diameter 62.035 mm? All these shapes will have
Step |
4) The combined effect of mass transferred in the x, y, and z directions is:
Locate the points on the pressure-enthalpy and the temperature-entropy charts:
Solve eqn (15.1) for q. and find the rate of heat absorbed in the evaporator:
Solve the problem using the spreadsheet program Evaporator.x/s. In the sheet “4-Effect Forward”, insert the data in the yellow cells and follow the instruc- tions. Insert a trial value for the heat transfer area in cells H18, J18, L18 and N18 and iterate until a “FINISH” signal is shown in the control panel. Check if the boiling temperature in cells H23 and N23 is 70 4 t 1°C and 40 4 t 1°C. If not, use another trial value for the heat transfer area and iterate. Repeat this proce- dure until the boiling temperature is equal to the given values. is equipped with a contact condenser with 150 m? heat transfer area for the condensation of the vapors exiting the fourth effect. The overall heat transfer coefficient in the condenser is 2500 W/m2°C. Find the required heat transfer area of each effect and the cooling water flow rate, so that the boiling tempera- ture in the first effect is 70 + 1 °C and in the last effect is 40 + 1 °C. Calculate the steam economy. Assume equal heat transfer area in the effects. Assume that the overall heat transfer coefficient changes as a function of temperature and con- centration according to: U = 400exp(0.03T)exp( — 2.5x,), where U is W/m? °C, T is temperature in °C, and x, is the solids mass fraction.
i) Find the relative humidity curve that passes through point A. i) Read the relative humidity on the relative humidity curve: Read RH = 60%
Step 4
Step | Air is being drawn over the cold surface of the cooling coil of an air conditioning unit. If 10 m?/min enters the air conditioner, calculate the mass flow rate of the condensed moisture, given that the air enters at 20°C and 70% relative humid- ity and exits at 12°C dry bulb temperature and 90% relative humidity. Calcu- late the refrigeration capacity of the coil in W and Btu/h.
aie “ie Find the slope of the curve of X vs t at various time values, or calculate ax vs or 4X vs X from the experimental data.
Fig. A.1_ Moody diagram of the friction factor for fluid flow inside pipes (equivalent roughness ¢, in m, for drawn tubing 1.5 x 10~°, commercial steel 46 x 10~°, galvanized iron 150 x 10~°, cast iron 260 x 10°) Based on Moody LF (1944) T ASME 66. Used with permission
Fig. A.2. Gurney-Lurie chart for a flat plate (1923) Ind Eng Chem 15. Used with permission
Fig. A.3 Gurney-Lurie chart for a long cylinder (1923) Ind Eng Chem 15. Used with permission
Fig. A.4 Gurney-Lurie chart for a sphere (1923) Ind Eng Chem 15. Used with permission
Fig. A.5 Heisler chart for determining the midplane temperature of a flat plate (1947) T ASME 69. Used with permission
Fig. A.6 Heisler chart for determining the centerline temperature of a long cylinder (1947) T ASME 69. Used with permission
Fig. A.7 Heisler chart for determining the center temperature of a sphere (1947) T ASME 69. Used with permission
Fig. A.8 Pressure- enthalpy diagram for HFC 134a with permission from DuPont
Fig. A.9 Pressure- enthalpy diagram for HFC 404a with permission from DuPont
Fig. A.10 Psychrometric chart with permission from Carrier
Table 1.1 Basic units Table 1.2 Derived units
Table 1.3. Conversion factors
Review Questions For a single wall
Table 10.2 Solutions of the unsteady state heat transfer equation for uniform initial tem- perature and both resistances, surface and internal, significant (0.1 <Bi<40) Table 10.3 Unsteady state heat transfer with negligible internal resistance (0.1 < Bi)
Table 13.1 Relations between heat and mass transfer parameters S. Yanniotis, Solving Problems in Food Engineering. © Springer 2008
(continued)
Table A.1 (continued)
Table A.2 First six roots of the equation: 6 tan 6 = Bi
Table A.3 First six roots of the equation: 6 J,(6)-Bi Jo(5) = 0
Table A.4 First six roots of the equation: 6 cot 6 = 1-Bi
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CENTRIFUGAL PUMPS Design & Application Second Edition
by Maxim Zemsky
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Control System Design - An Introduction to State-Space Methods - Bernard Friedland (Dover Publications)
by ulises modesto
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CONTOH PROPOSAL PKM-KC (PROGRAM KREATIVITAS MAHASISWA KARSA CIPTA) (Didanai DIKTI 2018)
by Meda Aji Saputro
Proposal ini sudah di publikasikan pada simposium RAPI 2018
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COATING INSPECTOR PROGRAM Level 2 Student Manual Jan 2014
by Denis Ryan
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Manufacturing Technology for Aerospace Structural Materials - F.C. Campbell
by Francisco Dávalos
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Shigley Mechanical Engineering Design SOLUTIONS MANUAL 2001
by Leonardo Riguerra
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Engineering Mechanics Statics 13th Edition-Solution Manual
by Ozzie Sahan
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CONDENSER AND COOLING TOWER PERFORMANCE AND ITS CALCULATIONS
by Ishan Gurung
Modified Rankine cycle is based on theory of Rankine cycle. Working of modified Rankine cycle is similar to that of Rankine cycle with some practical modification in the cycle to make it more operational. .1) THERMAL POWER PLANT CYCLE
1. Rankine cycle with reheat
FIG. 1.3: - RANKINE CY CLE WITH REGENERATION The regenerative features here effectively raise the nominal cycle heat input temperature, by reducing the addition of heat from the boiler/fuel source at the relatively low feed water temperatures that would exist without regenerative feed water heating. This improves the efficiency of the cycle, as more of the heat flow into the cycle occurs at higher temperature. This process ensures cycle economy.
below that of the atmosphere and this condition is referred to as the vacuum in the condenser.
‘he temperature difference between the exhaust steam and the cooling water is least at the top f the condenser where the cooling water leaves. Here the cooling water has its highest emperature. This particular temperature difference is very important and is given a special ame. It is called the terminal temperature difference. The important point is that any increase n this terminal difference leads directly to increase in the saturation temperature of the exhaust Lanann Ann n hsnhamn hAnnl nanccinTnn T.T.D. =Condensing Steam saturation temperature — Cooling Water outlet temperature name. It is called the terminal temperature difference. The important point is that any increase
However provision of own injection pump has to be made if water under pressure is not availabl.
impurities. A separate dry pump may be incorporated to maintain proper vacuum.
extraction pump is at the bottom.
2.According to the Positions or Arrangement of the condenser itself:
Fig. 2.7 Underslug -Axial or Transverse Condenser ondenses are mounted under the turbine at right angles to the turbine shafts.
Fig. 2.9 Pannier or side Mounted condenser.
shown in fig. 2.8 ii. Integral Condenser : In this condensers are arranged around the L.P. Turbine cylinders as
Fig 2.10 Single and Double Pass Condenser. mounted axially under the machine in line with the turbine shifts. The steam distribution is line
excessive upward thrust being passed on to the turbine foundation. Since the condenser has been floated over the springs, empty weight of the condenser is taken by the springs along with partial operating weight. The remaining operating weight is taken by the turbine foundation. While conducting hydraulic test in the shell side of the condenser wate1 is to be filled up into steam space up to one meter above the top tube row. Prior to filling water into condenser steam space for testing, jacking screws provided with spring support should be used for ensuring water weight being passed on to them, to avoid over stressing of springs. Prior to putting the system back in operation, condenser must be floated over springs to avoid ayceccive WoNWward thnict heing nassed on to the tirhine foundaton. used for ensuring water weight being passed on to them, to avoid over stressing of springs along with deaerator and boiler drum. Hot well is divided in the middle through a partition.
Thus the total losses in temperature are now 7°C and there are due to air in the example shown is 2°C. These emphases the importance of prevention of the air leaks and the removal of them condenser,
6.2) COMPONENTS IN COOLING TOWER: - down significantly. Cooling towers are able to lower the water temperatures more than devices subsequently discharged into the atmosphere. As a result, the remainder of the water is cooled
and the amount of air flowing. The greater the air flow, the greater the cooling achieved. 6.4) TYPES OF COOLING TOWERS
Fig6.4 a) Cross flow natural draft cooling tower_b) Counter flow natural draft cooling tower There are two main types of natural draft towers:
Thus, Range is a function of the heat load and the flow circulated through the system.
This is shown numerically in the following examples:
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Elemen Mesin
by Bernadi Ksatria
Dalam proses pembelajaran mata kuliah Elemen Mesin, mahasiswa diharapkan mampu memahami secara teoretik dan proses perhitungan sesuai kebutuhan dalam desain elemen mesin.
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Manufacturing Technology for Aerospace Structural Materials This Page is Intentionally Left Blank Manufacturing Technology for Aerospace Structural Materials
by Samuel Gerardo Varela Angles
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Guide for Transformer Maintenance Guide for Transformer Maintenance
by Emmanuel Romero Lima
Table 2: Possible Impacts on a Transformer by Lack of Maintenance Possible Impacts of on a Transformer by Lack of Maintenance
Figure 2: Theoretical Transformer Condition Degradation
To establish the limit values, refer to IEC60422 and IEEE Standard C57.106 2.4.1 Example 1: Oil Tests Reveal "Abnormal Values"
Figure 4: Decision Process in Cases of DGA Returning "Abnormal Values" 2.4.2 Example 2: DGA Reveals "Abnormal Values’
Figure 5: Decision Process after a Transformer Trip The following figure describes an example of corrective maintenance that is applied when a transformer has been tripped by its protection.
Like most processes, maintenance requires the input of data. Making prudent decisions over any activity to be performed on a power transformer, including maintenance, requires the availability of detailed lifetime data about the transformer, its operational and maintenance events, and data collected from performance records over its service history. The Maintenance Process can be summarized in four stages: Planning, Organization, Execution and Recording with a feedback stage providing for Optimization. These maintenance stages are shown in the following figure:
Figure 7: Linking between Transformer Inventory, Maintenance Guidelines and Task Lists Figure 7 below illustrates how the MMS creates links between a transformer in the Equipment Inventory and its Maintenance Guidelines and the detailed Task Lists.
Figure 8: Maintenance Events as Important Life Events The technical aspect of Maintenance Recording has a very important function that allows the maintenance crew to describ: in a structured way what maintenance was performed on a transformer and to enter this information into the transforme lifetime data management system. Maintenance data has an important place in the lifetime data of an individual transformer Maintenance data has to be considered beside the other data that is collected over the life of the transformer such a: operational data, environmental data and network events, with events starting from commissioning and recorded up unti scrapping of the unit, as represented in Figure 8 below.
Figure 9: Principal Types of Bushing Connections
Design enhancements and new materials have led to important transformer loss reductions over the last few decades. By example, Figure 26 shows how improvements in core steels and core assembly have reduced the per unit core loss in a transformer population belonging to a large North-American utility. It can be observed that in about 50 years, core losses have reduced by a factor of 10. When the costs of these losses are calculated over the expected lifespan of a refurbished transformer and converted into constant (actualized) expenses, they may amount to prohibitive levels. It is therefore essential that this consideration be taken into account early in the refurbishment decision of an older unit.
The transformer oil Conservator System typically consists of one or more externally mounted reservoirs (or expansion tanks). They are installed at the height required to provide an oil level in the transformer that is above the cover of the main tank of the transformer, or in many cases, above the highest oil filled bushing boss. Many Conservator Systems generally include a bladder inside the tank that provides an oil-to-air barrier to prevent moisture and dissolved air from entering the transformer oil. The system also has an air equalization line that allows air to enter the bladder when the transformer temperature is decreasing and air to discharge from the bladder when the temperature is increasing. There is also normally a desiccant container in line with this equalization line to dry the incoming air. Figure 10: Principal Oil Preservation Systems
4.4.5 Examples of Proper Gasket Mounting 4.5 Gauges, Indicators and Relays
Table 19: Comparative Maintenance Features of Different Switching Principles
Source: A. Kramer, "On-Load Tap-Changers for Power Transformers", MR Publication 2000 The following symbols are used in Table 21 to indicate the Diverter Switch and the tap selector:
Figure 13: Effect of Temperature on Dissipation/Power Factor (tand) Measurement nn RE The most common technique for assessing the condition of a bushing is the dissipation factor (DF) / power factor (PF) and capacitance measurement. Test results are then compared to nameplate values or previous tests. Increases or decreases from reference values are usually an indication of contamination and/or deterioration of the insulation system. Limits for the maximum permissible change tend to be manufacturer and type specific. A doubling of the initial dissipation/power factor value warrants either more frequent monitoring or replacement. A 10 % change in capacitance also warrants replacement. The temperature of the insulation can affect the dissipation/power factor results. Temperature correction factors for OIP and RIP bushings are shown below in Figure 13 [1]. The temperature of the bushing lies between the oil temperature of the transformer and the ambient temperature. The temperature of the oil and the ambient temperature should be recorded in the test report.
Figure 16: Dissipation/Power Factor Measurement on OIP Bushings at Different Frequencies {n its application to high voltage bushings, the measurement of Dissipation/Power Factor at low frequencies (some Hz) enables the detection of moisture with high sensitivity. Figure 16 below demonstrates the typical moisture sensitivity of tl Dissipation/Power Factor Measurement on OIP bushings between 20 Hz and 400 Hz.
Typical transient current responses are illustrated in Figure 18.
Figure 19: Modified Duval Triangle for OLTCs CIGRE Task Force D1-01-15 (TF15) started investigating DGA in OLTCs in 2005. The main emphasis has been on the interpretation of DGA results in order to obtain reliable fault diagnosis. DGA results from several networks with OLTCs ot the arc-breaking-in oil-type have thus been examined using the ABB Stenestam Code and a modified version of the Duva Triangle. Zones of normal operation, severe coking of contacts, light coking and abnormal arcing, together witt recommended procedures to formally identify the fault (hot spot or electrical) have been defined, taking into account the fact that the normal operation of these OLTCs produces a background of arcing gases in oil. Examples of such cases investigated by TF15, mostly reactor types, are presented below.
Figure 20: OLTC Drive Lubrication Problem Detected by Motor Current Measurement Motor Torque Measurement can provide valuable information on the drive assembly condition (links and gears, lubrication), the selector switch alignment and the diverter switch operation. The measurement is relatively simple and usually does not rely on a torque meter but rather uses motor supply parameters (current and voltage) to calculate motor power throughout the OLTC operation. With trending and comparisons, abnormal effects can be easily detected. A simpler measurement using only motor current will basically give the same indications but the abnormal deviations will sometimes not appear so clearly. An example of the detection of a lubrication problem is shown in Figure 20 below:
Figure 21: Evidence of Contact Wear on the Vibro-Acoustic Signature of a Diverter Switch Each tap change operation produces characteristic pressure and vibration waves that transmit through the oil and to the tan structure. It has been shown by numerous investigators, both for laboratory and in service operations, that any degradatio in the condition of the tap changer will involve a detectable change of the acoustic signature. Conversely, it has bee observed that this same signature varies only slightly in the case of a stable apparatus. Figure 21 below shows the influenc on contact wear on a Diverter Switch vibration signature.
Moisture in the oil especially when combined with particles, will significantly reduce the breakdown voltage of the oil and increases the risk of static electrification, partial discharge activity and tracking.
Cellulose is a natural polymeric material and the molecular chains making up the cellulosic polymer will break when exposed to high temperatures. This depolymerisation of cellulosic solid insulation is accelerated in the presence of moisture, oxygen and oil decay acids. 1% increase in the moisture content of the paper has the same effect as an increase of the operating temperature of 6-8°C (doubling the rate of depolymerisation). The aged paper will then become brittle and will loose its tensile strength. In cases of short-circuit fault or transportation movement, the insulation may tear, split or even fall off leading to serious dielectric failures.
High water content in the cellulose reduces the reliability of the unit because of the risk of bubbling in situations of overload or sudden loading where large increases in heat flux produce a sudden increase in temperature.
Literature: [1] P. Koestinger and al. "Practical experience with the drying of power transformer in the field, applying the LFH technology", CIGRE Session 2004 Figure 25 summarizes performance in terms of drying time for the different drying methods.
Table 40: Indicative DF/PF Limit Values for Condenser Bushing: (Source - “New Diagnostic for High Voltage Bushings”) Table 40: Indicative DF/PF Limit Values for Condenser Bushings As a guide, indicative limits for Dissipation/Power Factor in new and aged bushings at frequencies of 15 Hz, 50/60 Hz and 400 Hz are given in the following table.
Electrical Method for Partial Discharge (PD) Measurement Table 41: Electrical Method for Partial Discharge (PD) Measurement
Partial Discharge (PD) Measurement using UHF Technology
Frequency Response of the Stray Losses (FRSL) Literature:
The environmental impact of transformers over their life cycle has become an important consideration in many countries. Ir order to evaluate the impact of an individual transformer on the environment, a methodology called a Life Cycle Impac' Assessment (LCIA) can be used. The LCIA starts with a Life Cycle Inventory Analysis (LCI) to identify an inventory of the impacts on the environment of the main phases of the transformer during its entire life cycle. The impacts for each phase are then integrated and categorized as shown in Figure 27. The weighted sum of the impacts assessed for each of the four categories provides the overall Damage Value.
Fig 1. An example of GIT structure example of GIT structure, and Table 1 shows the basic feature comparison between OIT and GIT.
1-2 Cooling design / Layout design for GIT The concept (1-5) of the external cooling desigr for a GIT is nearly the same as that for an OIT; for this reason various types of cooling method can be applied.
Fig 2. Gas sampling Fig 3. Decomposed Gas checker set shows the gas checking set at site, same as that of GIS.
The following table describes some CIGRE references and standards applicable to transformer maintenance:
Table 3: Typical Maintenance Intervals The following table summarizes the typical maintenance practices that were reported in the survey. It remains for each user to determine which level is appropriate depending on the situation. It can also be noted that the maintenance level may be different for each action made on the same transformer population depending on each particular situation. As there are many factors that influence a maintenance policy, the maintenance "intensity" was divided into three different levels as described in the following table:
Table 5: Oil Impregnated Paper (OIP) Bushings This is the most common type of bushing insulation. The bushing core is made of paper impregnated with insulating oil anc has additional free oil between the core and the exterior insulator envelope.
ee EN yD IEE OEE NOES SI This type of bushing insulation is made of paper impregnated with resin. A resin-impregnated paper bushing can be provided with an insulating envelope. The intervening space can be filled with an insulating liquid or another insulating medium. ela, o> 9 a es eit ins tienes tall teleteiieios For direct connection to gas insulated switchgear (GIS), gas insulated bushings are used. These bushings use SF6 gas as th main insulation medium in conjunction with concentric metallic screens to control the electric field. Epoxy bushings ar growing in popularity for voltage applications up to 160 kV, where both the core insulation and the external housing ar made exclusively of epoxy. Resin Impregnated Paper (RIP)
Composite insulators are made either with an internal tube of glass resin surrounded by a silicone shell, or with epoxy in the case of the full epoxy design. The condenser body would typically be of the RIP design. Any space between the insulator and condenser core may be filled with oil, gel, solid foam or gas.
air flow that increases the heat loss from the radiator cooling surfaces. Furthermore, oil pumps can also be added to deliver hot oil quickly to the radiators for more efficient heat transfer.
this type of cooling, oil pumps force the oil to circulate through oil-water heat exchangers. In order to avoid any sibility of the two liquids mixing in the event of a leak, double tube technology is often used. 4.3.4 Oil Pumps
The winding hotspot temperature indicator (WTI) is intended to provide only a simulation of the winding hot spot temperature This simulation is created by a built-in thermal image device that essentially forces the WTI to indicate a temperature that 1: equal to top oil plus the hotspot gradient, instead of just the top oil temperature. This indicator reading is often only accurate a maximum nameplate rating load and then only if it is calibrated correctly. It should not be relied upon as being accurate Winding hot spot indicators are often used for turning on additional cooling fans and pumps. Electronic Indicator This technology, for measuring transformer temperature, uses a single RTD sensor that measures the top oil temperature and a current-transformer that measures the load on the transformer. Rather than using a heater, the indicator uses an algorithm with appropriates formulas, coefficients and exponents particular to the transformer design to calculate the winding temperature. The indicator then activates a series of dry contacts at different preset winding temperatures, to control the different cooling stages. Normally used in pairs, one indicator measures the top oil temperature, while the other represents the winding hotspot temperature. These indicators are typically sealed spiral-bourdon-tube dial type, with liquid-filled bulb sensors. The bulbs are normally inside separate thermometer wells that penetrate the tank in the hottest oil near the top of the tank. Each indicator will normally include a “drag” hand (usually red in colour) that indicates the maximum temperature reached since the last time it was reset.
Table 20: Comparative Maintenance Effort According to the OLTC Position in the Windings
Relays, Contactors and Circuitry - Checking required for relay coil failure, sticking or damaged contacts, condensation damage, gear box oil leaks and wiring integrity. 4.8.6 Typical Intervals - Manufacturer Recommendations Tap changer manufactures usually specify time-based maintenance that has to be carried out after either a certain number of tap-change operations, or after an elapsed time, whichever occurs first. Table 23 indicates the typical criteria for each of the OLTC types, and the effect that OLTC position and load may have on these intervals.
By assessing the dielectric integrity of the insulating oil for deterioration, contamination and moisture, the time-basec overhaul intervals can be considerably extended, and even eliminated in the case of some Vacuum Switch OLTCs.
Insulation Resistance
Table 34: Leakage Reactance (Short Circuit Impedance)
Breakdown voltage and water content are two parameters that may affect OLTC reliability. The following criteria are suggested: Table 48: OLTC Oil Tests
Table 51 below indicates the relative moisture level that could be achieved as criteria to stop the drying. The following table gives the definitions of the terms used in Table 51. 5.6.5 Remaining Relative Moisture Level
The Sorbent Material used mostly is Fuller's Earth. The term Fuller’s Earth refers to a class of naturally occurring adsorbent clays of varying mineral composition, and not a specific chemical. Fuller’s Earth clays may be used as bleaches, adsorbents, or oil reclamation compounds. The following table shows the typical composition of Fuller’s Earth:
Table 54: Different Requirements for Repairing Shell-Form and Core-Form
The comparative cost breakdown is summarized below expressed as a percentage of the supply cost of a new equivalent unit. In subtotal A, only the material and labour costs are compiled and it can be seen that the on-site repair and the factory repair options appear the least expensive.
Table 58: Comparative Costs — Case 2 The cost evaluation shows that the least cost option also provides the fastest restoration to full capacity at the power generation plant.
Table 59: Comparative Costs — Case 3
Systematic Preventive Maintenance (SPM) for GSU (page 1/2)
Systematic Preventive Maintenance (SPM) for Transmission Transformer (2"° part - page 1/2)
GIT and OIT, which realizes that GIT is able to be properly protected in operating.
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CHEMICAL ENGINEERING Solutions to the Problems in Chemical Engineering Volume 1
by NaNu Percy
PROBLEM 1.1 98% sulphuric acid of viscosity 0.025 N s/m 2 and density 1840 kg/m 3 is pumped at 685 cm 3 /s through a 25 mm line. Calculate the value of the Reynolds number. Solution Cross-sectional area of line D /4 0.025 2 D 0.00049 m 2... more
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Basic Engineering Design Guide R-0
by Daniel Fernandez
3.7.6. New PID for description of new or modified items and tie-ins location
Fig 9.1 Design Pressure of Tower and Auxiliaries
9.3. EQUIPMENT STEAM PURGING
10.1.4, Miscellaneous
In case that control valve without bypass is connected with interlock system, no hand wheel is provided.
Non-Hydrocarbon Drain for Pumps
) Pump, Fan, Blower, Turbine and Compressor
Table 10.4 Minimum Surge and Hold-up Time for Feed Surge Drum
Table 10.3 Minimum Surge and Hold-up Time in General *1 If the vessel can be considered part of a closed loop system (like lean/rich amine), use minimum 7.5 minutes for the
Table 10.6 Minimum Surge and Hold-up Time for KO Drum
1 the velocities and the pressure drop are as follows
Unless otherwise noted, Metric System Unit shall be used, for drawings and Calculation Report. 13.2. SITE PREPARATION AND EARTHWORK
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Introduction to Directional and Horizontal Drilling - Jim Short
by Jessica Silva Angulo
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Heat Transfer-Application-for-the-Practicing-Engineer-by-Louise-Theodore
by Trần Minh Nhật
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SOLUTION MANUAL
by mgk mgk
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TANK DESIGN DETAILING Introduction
by Antonio Luis
The API 650 standard is designed to provide the petroleum industry with tanks of adequate safety and reasonable economy for use in the storage of petroleum, petroleum products, and other liquid products commonly handled and stored by the... more
Types of tanks (based on Roof fixing)
Shop assembled AP! 650 tanks shall comply with Appendix J except that a minimum of spot radiography shall be applied with joint efficiency of 0.85. 1. TANK GA PREPARATION:
Lesser than 3” and 250 and above lg provide Stiffener plate 2 no apart 90 deg in 45 deg angle DETAIL OF LONG WELD NECK NOZZLE & NOZZLE WITH RF PAD
The number of manways to be provided are shown in the table below: Manways Types
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CONTOH PROPOSAL PKM-GT (PROGRAM KREATIVITAS MAHASISWA GAGASAN TERTULIS) (Didanai Dikti 2017)
by Meda Aji Saputro
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Handbook of Reliability Prediction Procedures for Mechanical Equipment NSWC 11
by internet toerist
Recognition of reliability and maintainability (R&M) as vital factors in the development, production, operation, and maintenance of today's complex systems has placed greater emphasis on the application of design evaluation techniques to... more
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The Self-Awareness Course for Teens
by Daniel M Keeran MSW
How well do you know yourself? You can learn to make healthy choices intentionally rather than to unconsciously repeat unhealthy patterns. This course is highly recommended for mental strengthening.
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Electrical installation guide 2013 According to IEC international standards
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Panduan pembelajaran materi tentang dasar star-delta dan motor induksi
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MECHANISMS & MECHANICAL DEVICES SOURCEBOOK Third Edition
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plant engineering
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A Plumbing Engineer's Guide to System Design and Specifi cations
by jean-pierre azzi
All rights reserved, including rights of reproduction and use in any form or by any means, including the making of copies by any photographic process, or by any electronic or mechanical device, printed or written or oral, or recording for... more
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Pompes et Stations de Pompage
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Diseño de Máquinas - Schaum
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Todos los Derechos Rese¡vados. Impreso en Colombia. Queda terminantemente prohibido reproducir este libro total o parcialmente sin permiso expreso de los editores. 91582 Traducido de la ptimera edición del original publicado én inglés... more
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TESTING THE HARDNESS OF METALS MECHANICAL PROPERTIES OF METAL
by Raphael Silva Augusto
This document is provided to customers, vendors, and associates of G.L. Huyett for technical information relating to the manufacture and sale of non-threaded industrial fasteners. As such, this document is not a design standard, design... more
Scrap steel is ferrous, or iron-containing material, that is remelted and recast into new steel. Recycling scrap steel accounts for up to 25% of oxygen furnace charge and up to 100% of the raw material for electric furnaces.
Keystock squares and rectangles are more difficult to draw than rounds because of the 90° anglex corners. Bars must be straight and true and the width must be in a perpendicular plane with th height. The surface finish of keystock must be free of pits and stresses so that installation is smoot! and efficient. Most customers prefer sharp corners for increased keyway contact (and minimal rocking) but edges must be sufficiently deburred for ease of use. The definition of keystock has been elusive because no single standard exists. Most technicians refer to “barstock” or “key barstock” as cold finished material drawn from market-ready grades to market- ready tolerances. “Keystock” refers to barstock carefully drawn to ANSI Class 2 fits.
Identifying metals When it is necessary to sort materials, several rough methods may be used without elaborate chemical analysis. The most obvious of these is by using a magnet to pick out those materials that contain magnetic elements. To differentiate various levels of carbon and other elements in a steel bar, hold the bar in contact with a grinding wheel and observe the sparks. With high levels of carbon, for instance, sparks are produced that appear to split into several bright tracers. Patterns produced by several other elements, including small amounts of aluminum and titanium, for instance, can be identified with the aid of Data Sheet 13, issued by the American Society for Metals (ASM), Metals Park, OH. This section sets forth specifications for the chemical content and physical properties for materials manufactured and sold by G.L. Huyett. The nomenclature used is in large part based on American Iron and Steel Institute (AISI) Standards.
Stress Stress is the force per unit area and is usually expressed in pounds per square inch. If the stress tends to stretch or lengthen the material, it is called tensile stress; if to compress or shorten the material, a compressive stress; and if to shear the material, a shearing stress. Tensile and compressive stresses always act at right-angles to (normal to) the area being considered; shearing stresses are always in the plane of the area (at right-angles to compressive or tensile stresses).
Ductility Ductility is the amount of steel to undergo permanent changes in shape without fracturing at room temperature. The opposite of ductility is brittle.
Indirect Hardening Case hardening (or indirect hardening) is applied to low-carbon content stee parts to increase surface hardness. During case hardening, carbon molecules are introduced to the part via solids, liquids, or gases in a process known as carburizing. The molecules penetrate the surface of the part, forming a casement, which is identified by the case depth (x) and surface hardness (y) More exacting specifications will identify an effective case (z) or a specific hardness requirement at < particular depth. Case hardness cannot be measured effectively using a Rockwell test. Readings mus be taken from a cross section of the part using a microhardness tester. Listed below are some terms and processes typically associated with case hardening (also known as indirect hardening):
Single Shear is the force required to break a part into two pieces. Shear strength is expressed as either single shear or double shear, depending on the engineering appl cation. Shear strength is tested as follows:
Inch to Millimeters and Millimeters to Inch Conversion Table
(Based on 1 inch = 25.4 millimeters, exactly)
Pound - Kilogram and Ounce - Gram Conversion Tables
Pound-Inches to Newton-Meters Conversion Tables
G.L. Huyett is unique in the breadth of its manufacturing operations. These operations ar complemented with a state-of-the-art world class warehouse containing over 75,000 non-threade fasteners and industrial components. This section sets forth some of the major manufacturin: operations performed by or contracted for by the company. A list of key capabilities and a define riche is listed for each.
Cold sawing is highly accurate and is used when fine length tolerances are considered.
ANSI sets forth two types with the following tolerance specifications: Many users of keystock have used the above specifications in their own product designs, which has led to two problems. First, because ANSI does not specify a grade, there is confusion. Second, most American mills will not produce to the Class 2 Fit. Tolerance is too low compared to other cold finished forms, and the draw is overly technical. As a result, there is often a difference between what customers want and what is available.
Chemical Composition Limits (%) of Steel— Iron makes up the remaining percentage. This Chart summarizes metallurgical properties of the various grades of tool steel available. The first step is applying data from the chart is to examine the specific application for the important properties involved. For example, an ejector pin for die-casting requires top toughness with good wear resistance and hot hardness —the chart indicates VDC as a logical start. If the VDC part wears too rapidly, the next move would be to Bearcat. Another application might involve a part for a short run cold forming die setup. Considering die life and steel cost, carbon would be first source —-if wear or size change in heat treatment becomes a problem, the next step would be to use Select B but if size change in heat treat was the only problem, then Badger should be tried.
Composition of AISI-SAE Standard Carbon Steels
a) Small quantities of certain elements are present that are not specified or required. These incidental elements may be present to the following maximur amounts: Cu, 0.35 per cent; Ni, 0.25 per cent; Cr, 0.20 per cent; and Mo, 0.06 per cent. b) Standard alloy steels can also be produced with a lead range of 0.15-0.35 per cent. Such steels are identified by inserting the letter “L” between the second and third numerals of the AISI or SAE number, e.g., 41L40. c) Electric furnace steel. d) 0.0005-0.003 per cent Source: American Iron and Steel Institute: Steel Products Manual. Compositions of AISI-SAE Standard Alloy Steels
Compositions of AISI-SAE Standard Stainless Steels
Typical Heat Treatments for SAE Carbon Steels (Direct Hardening) a) Slow cooling produces a spheroidal structure in these high-carbon steels that is sometimes required for machining purposes. b) May be water- or brine-quenched by special techniques such as partial immersion or time quenched; otherwise they are subject to quench cracking.
a) Symbols: A = water or brine; B = water or oil; C = cool slowly; D = air or oil; E = oil; F = water, brine, or oil. b) Even where tempering temperatures are shown, tempering is not mandatory in many applications. Tempering is usually employed for partial stress relief and improves resistance to grinding cracks. c) Activated or cyanide baths. d) May be given refining heat as in other processes. e) Carbonitriding atmospheres f) Normalizing temperatures at least 50 deg. F above the carburizing temperature are sometimes recommended where minimum heat-treatment distortion is of vital importance.
The Rockwell Hardness Scales The various Rockwell scales and their applications are shown in the following table. Comparison of Hardness Scales - All such tables are based on the assumption that the metal tested is homogeneous to a depth several times that of the indentation. To the extent that the metal being tested is not homogeneous, errors are introduced because different loads and different shapes of penetrators meet the resistance of metal of varying hardness, depending on the depth of indentation. Another source of error is introduced in comparing the hardness of different materials as measured on different hardness scales. This error arises from the fact that in any hardness test, metal that is severely coldworked actually supports the penetrator, and different metals, different alloys, and different analyses of the same type of alloy have different cold-working properties. In spite of the possible inaccuracies introduced by such factors, it is of considerable value to be able to compare hardness values in a general way.
Comparative Hardness Scales for Steel
Source: AlS| Committee of Hot-Rolled and Cold-Finished Bar Producers and published in 1974 DATABOOK issue of the American Society for Metals’ METAL PROGRESS magazine and used with its permission.
Hot Rolled, Normalized, and Annealed a) All grades are fine-grained except those in the 1100 series that are coarse-grained. Austenitizing temperatures are given ir parentheses. Heat-treated specimens were oil-quenched unless otherwise indicated. Source: Bethlehem Steel Corp. and Republic Stee Corp. as published in 1974 DATABOOK issue of the American Society for Metals’ METAL PROGRESS magazine and used with it: permission
a) All grades are fine-grained except those in the 1100 series that are coarse-grained. Austenitizing temperatures are given in parentheses Heat-treated specimens were oil-quenched unless otherwise indicated. bh) Water quenched.
a) All grades are fine-grained except those in the 1100 series that are coarse-grained. Austenitizing temperatures are given ii oarentheses. Heat-treated specimens were oil-quenched unless otherwise indicated. 5) Water quenched.
Source: Metals Handbook, 8th edition, Volume 1. a) Minimum. b) Depending on size and amount of cold reduction. c) Hardening temperature 1800 degrees F, 1-in.-diam. bar: d) Hardening temperature 1900 degrees F, 1-in.-diam. bar Nominal Mechanical Properties of Selected Standard Stainless Steels
Decimal Equivalents of Fractions of an Inch
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The ASME Code simplified
by Ludwig Homero Ríos Peña
Figure 1.1 The Brockton, Massachusetts, shoe factory. (Courtesy of The Hartford Steam Boiler Inspection and Insurance Company.)
Figure 1.2 Shoe factory after the boiler explosion of March 20, 1905, which led to the adop- tion of many state boiler codes and the ASME Boiler and Pressure Vessel Code. (Courtesy of The Hartford Steam Boiler Inspection and Insurance Company.)
Figure 1.3 Boiler and pressure vessel laws in the United States and Canada. (Reprinted with permission of the National Board of Boiler and Pressure Vessel Inspectors, www.nationalboard.org, from National Board Synopsis of Boiler and Pressure Vessel Laws, Rules and Regulations, © 2003.)
Figure 1.7 Stamping or nameplate of a boiler or pressure vessel repaired by welding. (Reprinted with permission from the National Board Inspection Code, 1992 ed., p. 49. Copyright 1992 National Board of Boiler and Pressure Vessel Inspectors.) Figure 1.6 Stamping or nameplate of an altered boiler or pressure vessel. (Reprinted with permission from the National Board Inspection Code, 1992 ed., p. 49. Copyright 1992 National Board of Boiler and Pressure Vessel Inspectors. )
Figure 2.3 Joint efficiencies for formed heads and unstayed flat head and covers with categories A and D butt welds. (Courtesy of Th American Society of Mechanical Engineers.)
TABLE 2.4b Shell Thickness Tables in Inches: Joint Efficiency=0.90
Figure 2.6 Constant factor versus stress.
Figure 2.7 Simplified external-pressure shell thickness chart: Carbon-steel yield strength is 30,000 to 38,000 psi; temperature, 300°F.
Figure 2.8 Simplified external-pressure shell thickness chart: Stainless steel (18 Cr—8 Ni) Type 304 temperature, 400°F.
TABLE 2.7a Torispherical Head Thickness Tables in Inches: Joint Efficiency=1.0
Figure 2.10 Flat head thickness chart, C=0.162. Figure 2.9 Flat head thickness chart, C=0.50.
Figure 2.11 Thickness chart for bolted flat cover plates with full-face gasket, C=0.25.
TABLE 2.12 Calculations for Conical and Toriconicat Heads
Figure 2.17 Illustration defining locations of welded joint categories. A. Longitudinal joints; circumferential joints connecting hemispherical heads to the main shell; any welded joint in a sphere. B. Circumferential joints; Circumferential joints of torispheri- cal, ellipsoidal heads; angle joints not greater than 30°. C. Flange joints; Van Stone laps; tube sheets; flat heads to main shell. D. Nozzle joints to main shell; heads; spheres; flat sided vessels.
Figure 3.1 Drying cylinder explodes when an almost foolproof safety device failed. (Courtesy of The Hartford Steam Boiler Inspection and Insurance Company.)
Figure 3.2 Door of cylinder. (Courtesy of The Hartford Steam Boiler Inspection and Insurance Company.)
TABLE 5.3 Full Radiographic Thickness Requirements’ Carbon and Low-Allow Steels TABLE 5.3 Full Radiographic Thickness Requirements* Carbon and Low-Allow Steels + P numbers and group numbers as given in Code Section IT], Part D, Table 1A, Pressure Vessel Code Section VIII, Division 1, and Code Table QW-422, ASME Code Section IX, Welding and Brazing Qualifications.
Figure 5.2 Stereoscopic principle in radiography. Any group of slag inclusions in a line with a total length greater than the thickness of plate in a length 12 times the plate thickness is unac- ceptable, except when the distance between the successive imperfec- tions exceeds 6 times the length of the largest imperfection. With full radiography, moreover, any type of crack or lack of penetration is not I ee a EE ee ee Sener ef, ee, Per eee omer Ee ee ee eee In heavy wall welds, knowing how deep a defect is from each side. helpful. We have seen chip-outs 2-in deep made in a 3-in weld thi could have been only 1-in deep from the opposite side if stereoscop principles of radiography had been used to make proper depth inte pretation. (See Fig. 5.2 for an example.) When available, ultrason techniques can and often are utilized to determine the depth of mar types of defects. Not every discontinuity in the film is objectionable vessels are fully radiographed (see Code Par. UW-51 and Appendix 4 The Code allows for a maximum length of slag inclusion according 1 the plate thickness as follows: % in for plates less than % in thick; | the plate thickness for plates % to 2% in thick; and % in for plates mo than 2% in thick. eS 6, a ee: ey i: eS es i: i: nS fe oe i. oe
Figure 5.3 Water pressure and temperature graph. all valves closed. During the night the water in the vessel warmed up expanded, and bulged out a flat stayed section. This accident occurrec¢ despite the cautionary footnote to Code Par. UG-99, which states: “A small liquid relief valve set to 143 times the test pressure is recom mended for the pressure test system, in case a vessel, while under test is likely to be warmed up materially with personnel absent.” (For ¢ graph showing the increase in water pressure caused by increase o water temperature, see Fig. 5.3.)
Figure 6.3 Welding qualification positions.
Figure 6.5 Longitudinal test specimens for plate materi- als.
Figure 6.6 Preparation of face, root, and side bend specimens.
Figure 6.7 Preparation of reduced section tension test specimens.
Figure 6.8 Fillet weld size. ing information on shop drawings. The Code gives fillet weld sizes for nozzles and flanges in terms of throat dimensions (to facilitate load calculations). The effective stress- carrying area is the throat dimension times the length of the weld. The American Welding Society's Standard Welding Symbols gives fillet weld sizes in terms of leg dimensions, and it is this measurement that should oe given to the shop rather than the throat dimensions. Calculations for leg sizes are illustrated and explained in Fig. 6.8. For example, if the Code-required throat dimension of a nozzle is 0.75 in, the leg size would oe 0.75 divided by 0.707, or 1.06 in, and it is this last figure that should appear on the drawing. If this is not done when the designer calls for a throat measurement of 0.75 in, the welder may assume a leg size of 0.75
Figure 6.9 American Welding Society’s standard welding symbols. (Courtesy of the American Welding Society.) On smaller vessels and pipe that cannot be welded from the inside, special care must be taken when fitting-up the abutting sections. This is especially true in pipe of uneven thickness, in which the proper fit-up of inside diameters is almost impossible to obtain. If there is sufficient thickness in the pipe wall, however, machining can
Figure 6.10 Welding details and symbols for shell plates and heads.
Figure 6.11 Welding details and symbols for nozzles and connections.
Figure 6.12 Miscellaneous welding details and symbols.
Figure 6.14 Metallurgical changes in ferritic materials at different fabrication and service temperatures.
Figure 6.15 Good design provides for expansion and contraction.
Figure 7.1 X-ray inspection of welds.
Figure 7.4 Magnetic particle inspection (longitudinal magnetic field). Figure 7.3 Magnetic particle inspection (circumferential magnetic field).
Figure 7.2 Gamma-ray inspection.
Acoustic Emission Testing
Figure 9.1 Quick Reference Guide: ASME Boiler and Pressure Vessel Code, Section I Power Boilers. (Courtesy of The Hartford Steam Boiler Inspection and Insurance Company. )
Figure 10.1 Pressurized water reactor (PWR). ihe pressurized water reactor (F Wi), wnich 18 1nsiae the containment vessel, is subjected to a high coolant water pressure. Here the pressur- ized water is heated. A pump circulates the heated water through a heat exchanger where steam for the turbine is generated. (See Fig. 10.1.) The part of the pressurized water nuclear power plant which con. tains the reactor coolant is called the primary circuit. Included in the primary circuit is an important vessel called the pressurizer. The coolant volume varies when load changes require coolant temperature changes. When this occurs, the pressurizer serves as the expansion tank in the primary system, allowing the water to undergo therma expansion and contraction and holding the primary circuit pressure nearly constant. If pressures were allowed to fluctuate too far, stear
Figure 10.2 Boiling water reactor (BWR).
Figure 11.1 MC-331 specification cargo tank. (Courtesy of National Tank Truck Carriers, Inc.)
Figure 11.2 Multiple tank specification plate markings.
Figure 11.3 Manufacturer’s Certificate of Compliance (typical). These federal regulations are available at the following address:
ities greater than 400 gallons. These manholes must be at least 15 in in diameter and be capable of withstanding a pressure test of at least 36 psig. The manhole covers must be permanently marked by the man- ufacturer with stamping or other means such as a nameplate. The owner or user who purchases the manhole cover must ensure that a certification statement is received, indicating that the cover complies with the regulations (see §178.345-5). 1 i) a RL es ey A: om a. cy i. a es a : es cn a.
Figure 11.6 Acceptable correct markings of cargo tanks upon completion of all required tests and inspections [§180.415(b)].
Figure 11.7 Unacceptable markings.
Figure 1.4 (Continued) CANADA
STAMPING REQUIREMENTS
CITIES, COUNTIES AND TERRITORIES OF THE UNITED STATES
CANADA
in accordance with provisions of the National Board Inspection Code FORM R-1 REPORT OF WELDED REPAIR
in accordance with provisions of the National Board Inspection Code
in accordance with provisions of the National Board Inspection Code
TABLE 2.1 Classes of Materials (Continued)
TABLE 2.1 Classes of Materials (Continued)
TABLE 2.2 Welded Joint Efficiency Values
TABLE 2.3 Radiographic Requirements For calculations involving the circumferential stresses of seam- less parts, or for thicknesses of seamless shells or heads, the value of E may equal 1.00 when the spot radiographic requirements of Code Par. UW-11(a)(5)(b) are met. Additionally, the value of E may equal 0.85 and may be utilized in the formula if the designer elects not to perform any radiography. The value of E = 0.85 for circum- ferential butt joints and longitudinal butt joints which connect seamless vessels, vessel sections, and heads, may be used provided that these welds are Type 3, 4, 5, or 6 joints as derived from Code Table UW-12.
TABLE 2.3 Radiographic Requirements (Continued) fH = 0.80 may continue to be used in Code calculations provided th welding process used is permitted by the rules of Section VIII, Divisio: 1 for the materials to be welded and provided that the quality of sucl welds are tested. Such test specimens shall be representative of th production welding on each vessel. These specimens may be taken fron the shell of the vessel or from a separate “runoff” tab attached as a pro trusion of the longitudinal joint of the vessel. If there is no longitudina joint, a separate test plate of the same base material, thickness, an welding materials which will be used on the production piece shall b used. Each test piece shall be tested with one reduced section tensio: test specimen and two side bend test specimens which shall meet th requirements of ASME Code Section IX Pars. QW-150 and QW-160. Ae «a woowlt af thse wawranimt ofhirianer vaniiPramant -allannmne a nar
Thinning due to the forming process and corrosion allowances are not included in these tables. The thickness equations for ellipsoidal and torispherical (flanged and dished) heads may be found in Table 2.8 (see also Code Par. UW-12). Table 2.9 sets forth the requirements and gives the location of the desired design calculations for various materials which may be planned to be used for Code construction. TABLE 2.6 Calculations for Cylindrical and Spherical Shells under External Pressure (Continued) Elements of Joint Design for Heads As stated in the beginning of this chapter regarding the new design thickness stress multipliers, a number of important factors must be considered in determining the thickness required for heads under in- ternal pressure, such as stress values, quality factors, and joint effi- ciencies, according to the degree of radiographic examination. Many designers have difficulty in determining these factors.
TABLE 2.11 Maximum Allowable Working Stress per Bolt (Standard Thread anc 8-Thread Series)
TABLE 2.12 Calculations for Conical and Toriconical Heads (Continued) Allowable Pressure, Pitch, and Thickness Areas of flat surfaces under internal pressure which are not supported have the tendency while under pressure to deform, bulge, and try to form a circle. An example of this phenomenon can be seen by blowing air into a cereal box. As pressure is applied to the box, the box becomes tubular in shape, and if one could blow hard enough, the box would rup- ture. The Code recognizes this problem and has included requirements for adding bracing or stays between these flat surfaces. Table 2.14 states the equations for braced and stayed surfaces and gives the Code references which apply. Mm LIT. O4Pr 2... hk... Ie CUR ]hClUl Re RI COA 2 Ae RRR Oe een ee ny nee ee
TABLE 2.14 Calculations for Braced and Stayed Surfaces
Table 2.16 is based on an allowable stress of 13,800 psi. For pressures using other stress values, divide the table pressure by the appropriate constant for the stress desired: Simplified Calculations for Reinforcement of Openings (Fig. 2.12) To determine whether an opening is adequately reinforced, it is first necessary to determine whether the areas of reinforcement available will be sufficient without the use of a pad. Figure 2.12 includes a schematic diagram of an opening showing the involved areas and also all the required calculations. The total cross-sectional area of rein- forcement required (in square inches) is indicated by the letter A, which is equal to the diameter (plus corrosion allowance) times the required thickness. The area of reinforcement available without a pad includes
fe) For bolting and nuts, the fallowing impact test exernption temperature shall apply: welds may be calculated from the equation W = S(A —- A,), in which § equals the allowable stress specified by Code Subsection C and Code Par. UW-15(c). For large openings in cylindrical shells, see Code Appendix 1-7. For openings in flat heads, see Code Par. UG-39. Fo weld sizes required, see Code Par. UW-16 and Code Fig. UW-16.1.] Or all welded vessels built under column C of Code Table UW-12, 80 per cent of the allowable stress value must be used in design formulas anc calculations. Table 2.17 states the requirements for openings and the reinforcement of these openings as well as detailing the applicable Code paragraphs.
TABLE 2.17 Openings and Reinforced Openings Cryogenic and Low-Temperature Vessels Use of cryogenic and low-temperature pressure vessels is increasing rapidly, but there have been many defects caused by improper materials and poorly designed vessels, particularly those meant for low-tempera- ture service. Many materials exposed to low temperatures lose their toughness and ductility. As the temperature goes down, the metal has a tendency to become brittle. This may cause brittle fracture at full stress. Most materials used for service at normal temperatures have a marked decrease in impact resistance as temperatures decrease. These materials must have the proven ability to safely resist high-stress changes and shock loads. Only impact-tested materials able to withstand unavoidable stress concentrations should be used for cryogenic vessels. All sharp or abrupt transitions or changes of sections, corners, or notches should be eliminated in the design of the vessel and fabrication of its parts.
GENERAL NOTE: See Fig. UCS-66 for SI values.
TABLE 3.1 Corrosion Allowances and Requirements temperature; the reaction of piping systems; the restricted therma expansion on attachment of piping systems to the vessel and on its hangers or anchors; the weight of valves; and pumps, blowers, anc rotating machinery. It is imperative for the designer to see that al machinery, piping, and equipment are properly balanced and sup. ported. Nonmandatory Code Appendixes D and G also give more use. ful information to be taken into consideration. Ties x eee a ok wee ee ak we ie Tee ed eae Lew, RK ie ee. Ree Se aed Ke dz
The minimum thickness of plate after forming and without allowances for corrosion shall not be less than the minimum thickness allowed for the type of material being used (see Code Pars. UG 16 and UG-25).
Figure 4.3 Inspection checklist.
WELDERS QUALIFICATIONS & PERFORMANCE RECORD LOG
The following formula is provided for convenience in calculating the bend specimen thickness:
TABLE 7.1 Analysis of Nondestructive Testing Techniques The manufacturer is responsible for seeing that all personnel pe: forming nondestructive examinations for Code vessels are competen and knowledgeable in applicable nondestructive examining requiré ments. They must be qualified in accordance with the requirements SNT-TC-1A. The intent of SNT-TC-1A is to serve as a guide for th qualification and certification of nondestructive test personnel. Thi document establishes the general framework for a qualification an certification program. It explains the various levels of qualification. | sives the requirements and shows the type of examination requirec Certification may take any one of several forms.
The manufacturer may employ persons previously trained and cer- tify these people. If this is done, the responsibility would be the same as if the manufacturer had trained and qualified these persons. The manufacturer may conduct a training program to meet the require- ments of SNT-TC-1A. This responsibility would be carried out through a designated employee who meets Level III requirements. This employee will train the persons, examine them, and certify them as to
TABLE 7.1 Analysis of Nondestructive Testing Techniques (Continued)
TABLE 7.1 Analysis of Nondestructive Testing Techniques (Continued) their ability to do nondestructive examinations. Through the examina- tions, this employee will be able to judge the qualifications of these per- sons for Level I and/or Level II certification. I In summarizing, a manufacturer must have qualified personnel. In addition, the manufacturer should have written procedures if the shop does nondestructive examinations. The Code requires that nondestruc- tive examining personnel be trained and qualified, also that their qual- ifications be documented as required in the referencing Code and SNT-TC-1A with its supplements and appendixes. It cannot be empha- sized too strongly that nondestructive examination of ASME Code pressure vessels must be performed by qualified personnel.
TABLE 7.1 Analysis of Nondestructive Testing Techniques (Continued)
TABLE 11.1 Effective Dates for Completing Construction As seen in the table, after September 1, 1993, the MC-306, MC-307, and MC-312 specifications will no longer be authorized for construc- tion; however, they will be permitted to be used in transporting haz- ardous materials after that date provided they were marked or certified on or before that date. After that date a new designation num- bering system along with more stringent manufacturing and design requirements will be employed. These new specifications are called DOT-406, DOT-407, and DOT-412 and will replace MC-306, MC-307, and MC-312, as discussed earlier in this chapter.
*ASOC = The American Society for quality Control.
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Manual of Engineering Drawing Manual of Engineering Drawing Second edition
by Enida Teletovic
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by Enrique Garcia
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