Safety valves installed in liquid pipelines due to thermal expansion
Thread Content
When considering the installation of safety valves for liquid pipelines, what does everyone use as a basis for making such decisions? Regarding project implementation, previously we considered installing safety valves between control valves, but not between manual valves. I wonder whether we should also consider installing safety valves between all manual valves
Are safety valves installed between all manual valves? I’ve really never seen anyone do that; it seems unnecessary. Installed between control valves? Are there multiple control valves between your pipelines as well? From a process perspective, it is still necessary to determine whether safety valves should be installed; install them where it is deemed necessary.
HG-T 20570.2-95 \"Installation and Selection of Safety Valves\"
There was a misunderstanding of clause 5.0.2.8 in the standard HG/T 20570.2-1995; it was overinterpreted, and indeed no consideration is needed for it. Meeting API 521 clause 4.4.12.4 is sufficient.
For isolation valves such as those used with liquid ammonia liquefied gas, safety valves are required to prevent overpressure by releasing any vaporized gas; you can take a look at the section on safety valves 20570