Pressure relief discharge pipe - inadequate piping

Foodface · Dec 1, 2012

Just been to do a load of gas safety checks on a block of flats, asides from having to I.D and disconnect a fire I came across another issue. I noticed that the pipe on the pressure relief valves, from the boilers I looked at were not quite right. Instead of exiting the property with two elbows, and pipework pointing towards the wall; they had a 22 mm stop end soldered onto the end of a straight piece of 15mm, leaving only a small gap for any potential pressure to be released from. I've highlighted this to the landlord and told him that it needs putting right. Has anyone come across this before, cos the landlord was insinuating I was wrong and tried to get the installer on the phone while I was there.

stevetheplumber · Dec 1, 2012

there are a lot of different designs of terminals for dischare pipes and most seem to be quite small openings i assume the cap is soldered at one point only
to be honest i wouldnt have worried about them as they fulfill the need to stop the water shooting straight out directing it back to the wall is the object

Foodface · Dec 1, 2012

Yeah they are soldered at one point, but only leave a very small gap for the water to discharge from. Guess my point is what happens if they get blocked up cos' the gap is tiny, where as if they were done in the more typical way they would have more clearance in terms of pipe diameter and less likely to get blocked.

lame plumber · Dec 1, 2012

you can get a tidy little mushroom ef fitting now to finish the prv outlet tidily, v small holes works ok

tamz · Dec 1, 2012

It is an easy way to do the prv from inside when it is hard to get access up to them. Nothing wrong with it.
The internal area of 15mm table x is 145.29mm3. The internal are of a 22mm cap end is 380.18mm3 (2.6 times greater)
It should be done like this.

Foodface · Dec 1, 2012

OK cleared that one up then, just seemed a bit odd but I shall take your responses and rescind my advise to the customer.

Thanks.

blade11 · Dec 1, 2012

Foodface said:
Just been to do a load of gas safety checks on a block of flats, asides from having to I.D and disconnect a fire I came across another issue. I noticed that the pipe on the pressure relief valves, from the boilers I looked at were not quite right. Instead of exiting the property with two elbows, and pipework pointing towards the wall; they had a 22 mm stop end soldered onto the end of a straight piece of 15mm, leaving only a small gap for any potential pressure to be released from. I've highlighted this to the landlord and told him that it needs putting right. Has anyone come across this before, cos the landlord was insinuating I was wrong and tried to get the installer on the phone while I was there.

different strokes for different folk alls well in my eyes