right. may i point out that 3226.2 of b31.3 requires that the disch piping from a psv shall have a facility for drainage. and the most cost effective way of meeting this reqt is by drilling a 6 mm drain hole. the absence of this tiny weeny hole may even be construed as a non-compliance.
ive check our psv disch piping on the the main steam line (idont even know why i did it - its hot). the end is square cut. page 93 piping guide by sherwood and whitstance "pipe exhausting to atmosphere is cut square, not at a slant as formerly done, as no real advantage is gained for the cost involved." API 520 and the crosby manual both showed a sqaure cut end for the disch. pipe.
-----Original Message-----
From: mechengr [mailto:mechengr1977@yahoo.com]
Sent: 23 March, 2002 11:32 AM
To: PipingDesign@yahoogroups.com
Subject: RE: [PipingDesign] query
the riser of the psv vent pipe can sometimes be signifivant msot especially if its located near a walkway or platform. API 520 equation to calculate the reaction force F included the term A0xP2 where P2 is the static pressure at the discharge. If you got a choke flow then F goes up and the resulting bending moment at the intersection of of the psv inlet and the header increases correspondingly.
Second, where would the collected condesate go - least of path resistance the psv. probably corrode a spring or the trim affecting over a period of time affecting the proper functioning of the psv.
Wont the set pressure of the psv affected as well becuase of the back pressure. Well, better make sure you got the holes drilled in the tail pipe.
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Received on Sat Mar 23 08:10:00 2002
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