ASME B31.5-2001 pdf download
ASME B31.5-2001 pdf download.REFRIGERATION PIPING AND HEATTRANSFER COMPONENTS.
soldered join:: a gas-tight joint obtained by the joining of metal parts with metallic mixtures or alloys that melt at temperatures not exceeding 840°F (449°C) and above 400°F (204°C).
submerged arc welding (SA W). an arc welding process wherein coalescence is produced by heating an arc(s) between a bare metal electrode or electrodes and the work. The arc is shielded by a blanket of granular fusible material on the work. Pressure is not used and filler metal is obtained from the electrode and sometimes from a supplementary welding rod.
tack weld: a weld made to hold parts of a weidment in proper alignment until the final welds are made.
throat of a fillet weld
actual: the shortest distance from the root of a fillet weld to its face.
theoretical: the distance from the beginning of the root of the joint perpendicular to the hypotenuse of the largest right-triangle that can be inscribed within the fillet-weld cross section.
roe of weld: the junction between the face of the weld and the base metal.
tube: see pipe.
undercut: a groove melted into the base metal adjacent to the toe or root of a weld and left unfilled by weld metal.
weld: a localized coalescence of metal wherein coalescence is produced by heating to suitable temperature, with or without the application of pressure, and with or without the use of filler metal. The filler metal has a melting point approximately the same as the base metals.
welder: one who is capable of performing a manual or semiautomatic welding operation.
welding operator: one who operates machine or automatic welding equipment.
welding procedures: the detailed methods and practices including all joint welding procedures involved in the production of a weidment.
weidment: an assembly whose component parts are joined by welding.
501.1 General
Paragraph 501 defines the temperatures, pressures, and various forces applicable to the design of piping systems. It also states considerations that shall be given to ambient and mechanical influences and various loadings.
501.2 Pressure
501.2.2 Internal Design Pressure. The piping component shall be designed for an internal pressure representing the most severe condition of coincident pressure and temperature expected in normal operation or standby (including fluid head). The most severe condition of coincident pressure and temperature shall be that condition that results in the greater required piping component thickness and the highest component rating.
Any piping connected to components other than piping shall have a design pressure no less than the lowest design pressure of any component to which it is connected.
501.2.3 External Design Pressure. The piping component shall be designed for an external pressure representing the most severe condition of coincident pressure and temperature expected during shutdown or in normal operation (including fluid head) considering possible loss of internal pressure. Refrigerant piping systems shall be designed to resist collapse when the internal pressure is zero absolute and the external pressure is atmospheric. This is to permit drying the pipe by evacuation. The most severe condition of coincident pressure and temperature shall be that condition that results in the greatest required pipe thickness and the highest component rating.
501.3 Temperature
In this Code, metal temperature of piping in service is considered to be the temperature of the fluid conveyed.
501.3.1 Brittle Fracture. Consideration must be given to a reduction in impact strength occurring in some materials when subjected to low temperatures.
Notch effects should be avoided. See para. 523.2.
501.4 Ambient Infuences
501.4.1 In the design of refrigeration piping systems, consideration must be given to the influence of ambient temperature.
501.4.2 Fluid Expansion Effects (Increased Pressure). Consideration must be given to expansion of liquid refrigerant trapped in or between closed valves and a means provided to prevent overpressure.
