Standards pipe fittings

Friction losses occurring as a result of a sudden enlargement or contraction in the cross-section of the pipe, and the resistance of various standard pipe fittings, are now considered. 

Details of the standard pipe fittings, welded, screwed and flanged, can be found in manufacturer s catalogues and in the appropriate national standards. The standards for metal pipes and fittings are discussed by Masek (1968). 

List the standard pipe fittings used to connect pipe. 

The coefficient of linear expansion of these alloys in the temperature range of 21 to 100°C (70 to 212°F) is 12.2 X lO C (6.8 X 10"V°F), which is slightly above that of cast iron (National Bureau of Standards). Since these loys have practically no elasticity, it is necessary to use expansion joints in relatively short pipe hnes. Connections for flanged pipe, fittings, valves, and pumps are made to 125-lb American Standarci drilling. 

Equation 2-25 is valid for calculating the head loss due to valves and fittings for all conditions of flows laminar, transition, and turbulent [3], The K values are a related function of the pipe system component internal diameter and the velocity of flow for v-/2g. The values in the standard tables are developed using standard ANSI pipe, valves, and fittings dimensions for each schedule or class [3]. The K value is for the size/type of pipe, fitting, or valve and not for the fluid, regardless of whether it is liquid or gas/vapor. 

A tabulated form as in Table 19.3. This shows flows versus pipe length and diameter for both copper and steel. Such tables are included in British Gas lM/16 and British Standard BS 6891. Note that Table 19.3 includes allowances for elbows, tees and bends. Allowances, equivalent to numbers of pipe diameters, must be made for all pipe fittings, which cause an additional pressure loss. Further details for allowances to be made for pipefittings, including valves and nonreturn valves, are given in Table 19.4. 

Equipment manufacturers also work to standards to produce standardised designs and size ranges for commonly used items such as electric motors, pumps, pipes and pipe fittings. They will conform to national standards, where they exist, or to those issued by trade associations. It is clearly more economic to produce a limited range of standard sizes than to have to treat each order as a special job. 

ASTM A 338, Standard specification for malleable iron flanges, pipe fittings, and valve parts for railroad, marine, and other heavy duty service at temperatures up to 650 °F (345 °C). 

In the laboratory, Swagelok pipe fittings are often used to set up plants. The Forschungszentrum Karlsruhe used these interfaces to define a modular platform which consists of modules for a number of standard unit operations. The modules are all equipped with these pipe fittings (Figure 4.10) and can thus be combined using the Swagelok interface standard ([68] see also [69]). 

A process scheme (Figure 4.87) consists of standardized surface-mount components and can be arranged on the screen to a customized system. The software also delivers a summary considering necessary seals and pipe fittings which can be used for ordering directly (Figure 4.88). 

D 5686 Standard Specification for Fiberglass (Glass Fiber Reinforced Thermosetting Resin) Pipe and Pipe Fittings, Adhesive Bonded Joint Type Epoxy Resin, for Condensate Return Lines... 

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