Valve tables

In order to cover all the lines in the facility, pipe and valve tables are normally included. Each pipe pressure class is assigned a designation. Sometimes it is necessary to assign two classes for a single designation. For ample, in Table 15-1 A, L, and AA are all ANSI 150 cl , but they contain different fluids. 

The computer program PROG52 calculates the control valve capacity coefficient (C ) or the maximum flow rate that will pass through the valve. Table 5-9 shows the input data and results of the control valve calculations for liquid, gas, and steam conditions. For the liquid service, at a flow rate of 400 gpm and the control valve pressure drop of 25 psi, the control valve capacity coefficient (CJ is 80. The gas service with a flow rate of 1200 fP/h, and control valve pressure drop of 400 psi gives the control valve capacity coefficient (C ) of 0.059. For the steam condition of capacity coefficient (C, ) = 75, and the control valve pressure drop of 10 psi, the maximum steam flow rate through the valve is 5511.4 Ib/hr. 

B. Valves. Table 9.21 summarizes the application of various types of valve, according to the same four classes used for piping services in Fig. 9.60. The table has the status of a recommendation rather than a hard specification. Exceptions exist, but they should be made only after thorough testing and documentation. All practical combinations are listed, but threaded valves usually should be considered only for connection to transportation equipment, instruments, and special process equipment. Flanged valves generally are preferred. 

However, these modifications cannot be implemented on a stand-alone as they would cause feed vaporization and flash before heater control valves (Table 23.2). To assess the effects of these modifications on feed vaporization, the bubble point (BP) as a function of feed temperature was calculated. This calculation is shown in Figure 23.1, which shows the actual feed temperature and pressure while the line indicates the bubble point as a function of feed temperature. The triangle above the line indicates severe feed vaporization could occur if three modifications... 

The corrosion resistance of nickel alloys has been extensively explored in seawater and saltwater (brackish water). Although stainless steel 316 is known to resist pitting in seawater, stainless steels are, in general, susceptible to pitting in the tidal zones of seawater. The nickel alloys, more expensive than steels, have been extensively used in seawater service. Inconel alloy 625 offers an excellent resistance to corrosion in seawater. It also offers an excellent resistance to SCC. Nickel alloys are best used for pump shafts, bodies and impellers while other materials, like 90-10 Cu-Ni and austenitic steels are used for other parts, such as heat exchangers and valves. Table 9.47 shows the classification of selected nickel alloys in seawater service. 

WISR-8 has been implemented at SRS. A list of key valves has been prepared based on their importance to safety. These valves were disassembled, and their internal parts were checked and evaluated. The WISR 8 inspection requirements are, documented in RTM-4987 (Reference 24). The valves inspected are listed in Section III of the WISR items and in the Section IV valve tables of the restart I T plan. 

Steel. The steel container s most usual form is cylindrical with a concave (or flat) bottom and a convex top dome with a circular opening finished to receive a valve with a standard 2.54-cm opening. The three pieces (body, bottom, and top) are produced separately and joined by high speed manufacturing. The size of the container is described by its diameter and height to top seam, in that order. Hence a 202 x 509 container is 54.0 mm (2 /jg in.) in diameter by 141.3 mm (5 /jg in.) high. Tables of available sizes and overflow volumes and suggested fill levels can be readily obtained from manufacturers. 

An EMEA table contains a series of columns for the equipment reference number, the name of the piece of equipment, a description of the equipment type, configuration, service characteristics, etc, which may impact the fadure modes and/or effects, and aflst of the fadure modes. Table 2 provides a Hst of representative fadure modes for valves, pumps, and heat exchangers. The last column of the EMEA table is reserved for a description of the immediate and ultimate effects of each of the fadure modes on other equipment and the system. 

The flow resistance of pipe fittings (elbows, tees, etc) and valves is expressed in terms of either an equivalent length of straight pipe or velocity head loss (head loss = Kv /2g ). Most handbooks and manufacturers pubHcations dealing with fluid flow incorporate either tables of equivalent lengths for fittings and valves or K values for velocity head loss. Inasmuch as the velocity in the equipment is generally much lower than in the pipe, a pressure loss equal to at least one velocity head occurs when the fluid is accelerated to the pipe velocity. 

For laminar flow, data for the frictional loss of valves and fittings are meager. (Beck and Miller,y. Am. Soc. Nav. Eng., 56, 62-83 [194fl Beck, ibid., 56, 235-271, 366-388, 389-395 [1944] De Craene, Heat. Piping Air Cond., 27[10], 90-95 [1955] Karr and Schutz, j. Am. Soc. Nav. Eng., 52, 239-256 [1940] and Kittredge and Rowley, Trans. ASME, 79, 1759-1766 [1957]). The data of Kittredge and Rowley indicate that K is constant for Reynolds numbers above 500 to 2,000, but increases rapidly as Re decreases below 500. Typical values for K for laminar flow Reynolds numbers are shown in Table 6-5. 

TABLE 6-4 Additional Frictional Loss for Turbulent Flow through Fittings and Valves ... 

Threadless copper pipe, thinner than ASTM B42, is available with dimensions as in Table 10-34. Solder-end fittings similar to ANSI B16.15 screwed fittings and solder-end valves are used with this pipe. 

TABLE 10-45 Pressure-Temperature Ratings for FlangeS/ Flanged FittingS/ and Flanged Valves of Typical Materials/ Ibf/in ... 

In the absence of more direc tly applicable data, the flexibility factor k and stress-intensification factor i shown in Table 10-54 may be used in flexibihty calculations in Eq. (10-101). For piping components or attachments (such as valves, strainers, anchor rings, and bands) not covered in the table, suitable stress-intensification factors may be assumed by comparison of their significant geometry with that of the components shown. 

The peripheral stiffening zone (tray ring) is generally 25 to 50 mm (1 to 2 in) wide and occupies 2 to 5 percent of the cross section, the fraction decreasing with increase in plate diameter. Peripheiy waste (Fig. 14-28) occurs primarily with bubble-cap trays and results from the inabihty to fit the cap layout to the circular form of the plate. Valves and perforations can be located close to the wall and little dead area results. Typical values of the fraction of the total cross-sectional area available for vapor dispersion and contact with the liquid for cross-flow plates with a chord weir equal to 75 percent of the column diameter are given in Table 14-6. 

FIG. 17-16 Solids-flow-control devices, a) Slide valve, (h) Rotary valve, (c) Table feeder, (d) Screw feeder, (e) Cone valve, (f ) L Valve. 

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