Spec Breaks
Spec Breaks
(OP)
I have a line coming off of a 300# spec line, a block valve, another block valve, and then the line returns to the 300# spec line. Between the two block valves there is a branch, a block valve (normally closed) and then the branch flows into a sewer header (150#) that feeds into an atmospheric tank. Why is it okay to have a 300#/150# spec break downstream of the block valve in the branch line? I have attached a drawing to try to clear my description up. Thanks.





RE: Spec Breaks
What your sketch shows looks fine to me, assuming that the "sewer" is open to atmosphere. The spec break is on the downstream side of the last isolation valve. If you close the valve then everything (including the valve) is rated for the upstream pressure. The downstream piping should never see higher pressures than 150# rating because flow rate can never be high enough to generated that sort of back pressure. (unless you get a blockage
RE: Spec Breaks
Is the schedule of the pipe different?
RE: Spec Breaks
RE: Spec Breaks
RE: Spec Breaks
continuing line ( you can lay the break there),
but when You want to add another 300# system later You have to demolish the line, (except when You can upgrade the pipe; p.e. when it's the same schedule)
Greetings
RE: Spec Breaks
RE: Spec Breaks
English is not my native language.
But when I look at the picture it's only a piece of pipe with atmospheric conditions.
So why should You use a different pipespec. and maybe a different pipeschedule?
Greetings.
RE: Spec Breaks