General Definitions
Absolute Viscosity. Absolute viscosity or the coefficient of absolute viscosity is a measure of the internal resistance. In the centimeter, gram, second (cgs) or metric system, the unit of absolute viscosity is the poise (abbreviated P), which is equal to 100 centipoise (cP). The English units used to measure or express viscosity are slugs per foot-second or pound force seconds per square foot. Sometimes, the English units are also expressed as pound mass per foot-second or poundal seconds per square foot.
Adhesive Joint.
A joint made in plastic piping by the use of an adhesive substance which forms a continuous bond between the mating surfaces without dissolving either one of them.
Air-Hardened Steel.
A steel that hardens during cooling in air from a temperature above its transformation range.
Alloy Steel.
A steel which owes its distinctive properties to elements other than carbon. Steel is considered to be alloy steel when the maximum of the range given for the content of alloying elements exceeds one or more of the following limits.
Manganese 1.65 percent
Silicon 0.60 percent
Copper 0.60 percent
or a definite range or a definite minimum quantity of any of the following elements is specified or required within the limits of the recognized field of constructional alloy steels:
Aluminum Nickel
Boron Titanium
Chromium (up to 3.99 percent) Tungsten
Cobalt Vanadium
Columbium Zirconium
Molybdenum
or any other alloying element added to obtain a desired alloying effect.
Small quantities of certain elements are unavoidably present in alloy steels. In many applications, these are not considered to be important and are not specified or required. When not specified or required, they should not exceed the following amounts:
Copper 0.35 percent
Chromium 0.20 percent
Nickel 0.25 percent
Molybdenum 0.06 percent
Ambient Temperature.
The temperature of the surrounding medium usually used to refer to the temperature of the air in which a structure is situated or a device operates.
Anchor.
A rigid restraint providing substantially full fixation, permitting neither translatory nor rotational displacement of the pipe.
Annealing.
Heating a metal to a temperature above a critical temperature and holding above that range for a proper period of time, followed by cooling at a suitable rate to below that range for such purposes as reducing hardness, improving machinability, facilitating cold working, producing a desired microstructure, or obtaining desired mechanical, physical, or other properties.(A softening treatment is often carried out just below the critical range which is referred to as a subcritical annealing.)
Arc Cutting.
A group of cutting processes in which the severing or removing of metals is effected by melting with the heat of an arc between an electrode and the base metal (includes carbon, metal, gas metal, gas tungsten, plasma, and air carbon arc cutting). See also Oxygen Cutting.
Arc Welding.
A group of welding processes in which coalescence is produced by heating with an electric arc or arcs, with or without the application of pressure and with or without the use of filler metal.
Assembly.
The joining together of two or more piping components by bolting, welding, caulking, brazing, soldering, cementing, or threading into their installed location as specified by the engineering design.
Automatic Welding.
Welding with equipment which performs the entire welding operation without constant observation and adjustment of the controls by an operator. The equipment may or may not perform the loading and unloading of the work.3,5
Backing Ring.
Backing in the form of a ring that can be used in the welding of piping to prevent weld spatter from entering a pipe and to ensure full penetration of the weld to the inside of the pipe wall.
Ball Joint.
A component which permits universal rotational movement in a piping system.