Now with Piping & Fabrication, we will entering the Piping Components and here we are start with the Introduction.
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| Table A2.1 Prevalent Piping Specifications |
The term piping refers to the overall network of pipes, fittings, flanges, valves, and other components that comprise a conduit system used to convey fluids. Whether a piping system is used to simply convey fluids from one point to another or to process and condition the fluid, piping components serve an important role in the composition and operation of the system. A system used solely to convey fluids
may consist of relatively few components, such as valves and fittings, whereas a complex chemical processing system may consist of a variety of components used to measure, control, condition, and convey the fluids. In the following sections, the characteristics and functions of the various piping components are described.
PIPE AND TUBE PRODUCTS
Pressure pipe and tube products are
manufactured to a variety of standard specifications of varying designs, employing different manufacturing practices and using a wide variety of materials. The end user of these products must apply the leastcost product suitable for the specified service conditions. Typically, steel and alloy pressure piping is available in cast, wrought, and seam-welded forms. Welded and seamless wrought steel pipe is supplied in standard sizes and wall thickness conforming to ASME B36.10M. Stainless-steel pipe is supplied in standard sizes and wall thickness conforming to ASME B36.19M. These standard pipe dimensions are tabulated in Apps. E2 and E2M, and the metric size equivalent DN of the NPS is given in Chap. A1. Some commonly specified piping materials are listed in Table A2.1.
Pressure Tubing
Pressure-tube applications commonly involve external heat applications, as in boilers or super heaters. Pressure tubing is produced to the actual outside diameter and minimum or average wall thickness specified by the purchaser. Pressure tubing may be hot- or cold-finished. The wall thickness is normally given in decimal parts of an inch rather than as a fraction or gauge number. When gauge numbers are given without reference to a system, Birmingham wire gauge (BWG) is implied. Weights of commercial tubing are given in Apps. E3 and E3M. Pressure tubing is usually made from steel produced by the open-hearth, basic oxygen, or electric furnace processes. Seamless pressure tubing may be either hot finished
or cold-drawn. Cold-drawn steel tubing is frequently process-annealed at temperatures above 1200OF (650OC). To ensure quality, maximum hardness values are frequently specified. Hot-finished or cold-drawn seamless low-alloy steel tubes generally are process-annealed at temperatures between 1200OF (650OC) and 1350OF (730 OC). Austenitic stainless-steel tubes are usually annealed at temperatures between 1800OF (980 OC) and 2100OF (1150 OC), with specific temperatures varying somewhat with each grade. This is generally followed by pickling, unless bright annealing was done.
Pipe Fittings
The major piping materials are also produced in the form of standard fittings. Among the more widely used materials are ductile or cast iron, malleable iron, brass, copper, cast steel, forged steel, and wrought steel. Other major nonferrous piping materials are also produced in the form of cast and wrought fittings. Ductile and cast-iron fittings are made by conventional foundry methods for a variety of joints including bell-and-spigot, push-on flanged, and mechanical (gland-type) or other proprietary designs.
may consist of relatively few components, such as valves and fittings, whereas a complex chemical processing system may consist of a variety of components used to measure, control, condition, and convey the fluids. In the following sections, the characteristics and functions of the various piping components are described.
PIPE AND TUBE PRODUCTS
Pressure pipe and tube products are
manufactured to a variety of standard specifications of varying designs, employing different manufacturing practices and using a wide variety of materials. The end user of these products must apply the leastcost product suitable for the specified service conditions. Typically, steel and alloy pressure piping is available in cast, wrought, and seam-welded forms. Welded and seamless wrought steel pipe is supplied in standard sizes and wall thickness conforming to ASME B36.10M. Stainless-steel pipe is supplied in standard sizes and wall thickness conforming to ASME B36.19M. These standard pipe dimensions are tabulated in Apps. E2 and E2M, and the metric size equivalent DN of the NPS is given in Chap. A1. Some commonly specified piping materials are listed in Table A2.1.
Pressure Tubing
Pressure-tube applications commonly involve external heat applications, as in boilers or super heaters. Pressure tubing is produced to the actual outside diameter and minimum or average wall thickness specified by the purchaser. Pressure tubing may be hot- or cold-finished. The wall thickness is normally given in decimal parts of an inch rather than as a fraction or gauge number. When gauge numbers are given without reference to a system, Birmingham wire gauge (BWG) is implied. Weights of commercial tubing are given in Apps. E3 and E3M. Pressure tubing is usually made from steel produced by the open-hearth, basic oxygen, or electric furnace processes. Seamless pressure tubing may be either hot finished
or cold-drawn. Cold-drawn steel tubing is frequently process-annealed at temperatures above 1200OF (650OC). To ensure quality, maximum hardness values are frequently specified. Hot-finished or cold-drawn seamless low-alloy steel tubes generally are process-annealed at temperatures between 1200OF (650OC) and 1350OF (730 OC). Austenitic stainless-steel tubes are usually annealed at temperatures between 1800OF (980 OC) and 2100OF (1150 OC), with specific temperatures varying somewhat with each grade. This is generally followed by pickling, unless bright annealing was done.
Pipe Fittings
The major piping materials are also produced in the form of standard fittings. Among the more widely used materials are ductile or cast iron, malleable iron, brass, copper, cast steel, forged steel, and wrought steel. Other major nonferrous piping materials are also produced in the form of cast and wrought fittings. Ductile and cast-iron fittings are made by conventional foundry methods for a variety of joints including bell-and-spigot, push-on flanged, and mechanical (gland-type) or other proprietary designs.
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