P&ID questions
P&ID questions
(OP)
I have a difficulty in understanding this convention. Please let me know, what I can infer from the below convention.
PIS-+A-+
and LS++A++
and so on.
Thank you,
PIS-+A-+
and LS++A++
and so on.
Thank you,





RE: P&ID questions
But relax, if you look at page 1 in your P&ID book you should find a legend that tells you everything you need.
RE: P&ID questions
LS is level switch. A is alarm.
PIS is unusual but would be pressure indicating switch. For example, Mercoid makes a bourdon tube pressure gauge switch. The alarms often include an associated suffix like H for high and L for low.
RE: P&ID questions
LS++A++ switch at high-high level, alarm at high-high level
Often you will find a "slang" written and the signs are not fully conforming to ISA.
RE: P&ID questions
It was so nice to get the answer.
Thanks a lot once again.