Relief Valve Piping, 90's & 45's

[Brian G]

I've seen posts before about how many 90's and / or 45's are allowed in relief valve piping, but the info is hiding in one of the many dark corners of my brain. Does anyone know it off the top of their head?

I just looked at one with five 90's and one 45. Seems like too much.

Brian G.

Rube Goldberg relief piping?

[Terence McCann]

Hello Mr. G:

Four 90s.

http://www.wattsreg.com/default.htm?/t& ... lation.htm

or

http://66.132.184.14:8080/~ashi/upload/T&P.pdf

[Brian G]

Gracias Mr. Mc,

I knew that didn't look right. They could have easily piped it down to the garage floor, but they worked it way down a wall to the exterior. It is permissable to empty onto a concrete garage floor isn't it (6" above the floor)? All I can find is "a safe place of disposal", but it also says to keep the pipe as short as possible.

I've seen it both ways, but I kinda like the garage floor because you would notice if it started leaking or discharging. I'm not sure there is a "safe" place to vent scalding hot water and steam under pressure.

Brian G.

[hausdok]

Hi Brian,

They don't pop off like that - at least none of the ones that I've ever seen venting did. They spit a little at a time - enough to relieve pressure - and then they close again, unless the temp is over boiling. In any event, by the time the water trickles to the end of a long run of copper pipe it will be hot when it drips clear but it shouldn't be scalding.

Around here they vent about half of them to the outside, the rest are vented to within 6 and 24 inches of the floor. Most of them are in the garage here unless it's older construction.

ONE TEAM - ONE FIGHT!!!

Mike

[Terence McCann]

As long as it isn't over 30'. Personally I would rather see it in a garage where a weeping valve would be noticed.