By CWI555 
Date 07-16-2009 00:03
Edited 07-16-2009 00:10
Giovanni,
A quote from B31.8 2007:
"802.12 This Code does not apply to
(a) design and manufacture of pressure vessels covered
by the BPV B31.1
(b) piping with metal temperatures above 450°F or
below −20°F (For low temperature within the range covered
by this Code, see para. 812.)
(c) piping beyond the outlet of the customer’s meter
set assembly (Refer to ANSI Z223.1 and NFPA 54.)
(d) piping in oil refineries or natural gasoline extraction
plants, gas treating plant piping other than the main
gas stream piping in dehydration, and all other processing
plants installed as part of a gas transmission
system, gas manufacturing plants, industrial plants, or
mines (See other applicable sections of the ASME Code
for Pressure Piping, B31.)"
(e) vent piping to operate at substantially atmospheric
pressures for waste gases of any kind
(f) wellhead assemblies, including control valves,
flow lines between wellhead and trap or separator, offshore
platform production facility piping, or casing and
tubing in gas or oil wells. (For offshore platform production
facility piping, see API RP 14E.)
(g) the design and manufacture of proprietary items
of equipment, apparatus, or instruments
(h) the design and manufacture of heat exchangers
(Refer to appropriate TEMA2 Standard.)
(i) liquid petroleum transportation piping systems
(Refer to ASME B31.4.)
(j) liquid slurry transportation piping systems (Refer
to ASME B31.11.)
(k) carbon dioxide transportation piping systems
(l) liquefied natural gas piping systems (Refer to
NFPA 59A and ASME B31.3.)
Based on that, it is my opinion that B31.8 stops at the meter, and begins where the process piping ends in an LNG facility. It may be used where no regassification or liquification is utilized. The -20 degree limitation also helps define it.
Regards,
Gerald
