Thanks one & all for all the useful bits, especially about the cavity inside a ball valve.
I think that I now have more than enough to continue my Design.
Thansk all again,
Andy (Englishman in France!!)
I am currently working on an LNG job and a question had come up as to the the minimum volume of blocked-in pipework (between 2 isolation valves) that require the addition of a Thermal PSV.
I have some very small inventories (of the order of 5 litres) on the LNG piping; the LNG will vaporise when...