A computer program has been developed to evaluate piping systems in which cryogens are used as the fluid medium. It covers piping systems (series, parallel, and series-parallel network) with typical cryogens (hydrogen, helium, nitrogen, oxygen, argon, and methane) in the temperature range from 2K to 400K and the pressure range from 0 bar to 1,200 bar. With data on thermodynamic and transport properties of cryogens, the calculated results show a significant difference between using constant cryogenic properties and updated properties. This program is probably the first of its kind in the public domain that accounts for variable cryogenic properties. It indicates that for some cryogens, such as hydrogen, helium, and argon, using constant fluid properties in piping system calculations will create non-negligible errors in the results of pressure drop, flow-rate and pipe diameter. This program advises when constant cryogenic properties are adequate and when their variability must be taken into account. This program, which could update cryogenic properties is recommended for the calculations and design of cryogenic piping systems.

KEYWORDS: computer programs, pipes, cryogenics, properties, calculating, hydrogen, nitrogen, oxygen, argon, methane, helium, accuracy, pressure drop, flow rate, diameter, designing