First Fix Plumbing - can I do it myself?

[Rickyy]

Wet testing at 1.5 times the working pressure is all that is needed.

The heating system should never see more than 3 bar, so testing it at 4.5 bar is more than adequate.

[Woody3]

Thanks chaps.

Good to know about the air side of things. Is wet testing easy enough to do? I assume there is a machine that I need to hire to do this?

We're just on the heating circuit at the moment, but so far so good. A few things I hadn't anticipated, but nothing that I wasn't going to do at a later date.

It did, however, take half a day to clear the void in the ceiling above the GF staircase to run the 2 x 22mm pipes across. Looks like a previous builder used this area as a skip. Pulled no end of bricks and rubble from there. Had to remove it all through a brick and half size hole in the wall to either side of the staircase. The amount removed would have easily filled a dustbin - surprised it didn't make the ceiling collapse!

[pghstochaj]

Amazed at the idea of pneumatically pressure testing and devices being sold to support this. I work in process engineering and pneumatic is the last choice if nothing else is possible - for example if water would contaminate a line. When we do the air test we follow a detailed ramp up procedure and risk assessment which includes removing everybody from the site. The working pressure of a typical process compressed system is 7 bar so they are usually tested around 10-12 bar so this is the same ballpark. Air is a compressible fluid so it can store a lot more energy than water which is essentially incompressible. There are some fantastic videos on YouTube comparing the impact of pneumatic and hydraulic tests...I don’t think I would pneutmatically test unless I could avoid it.

[samdale]

pghstochaj said:

Amazed at the idea of pneumatically pressure testing and devices being sold to support this. I work in process engineering and pneumatic is the last choice if nothing else is possible - for example if water would contaminate a line. When we do the air test we follow a detailed ramp up procedure and risk assessment which includes removing everybody from the site. The working pressure of a typical process compressed system is 7 bar so they are usually tested around 10-12 bar so this is the same ballpark. Air is a compressible fluid so it can store a lot more energy than water which is essentially incompressible. There are some fantastic videos on YouTube comparing the impact of pneumatic and hydraulic tests...I don’t think I would pneutmatically test unless I could avoid it.

Maybe it's just the industry you're in? I work in oil and gas and ~100bar nitrogen leak testing is common place. Important to note is how close this is to MAOP of the system. Typically our testing is at 90% of the relief valve set pressure. Occasionally at 110%.

[hobbiniho1]

OP what you are looking for is a tangy pump to do a hydrostatic hold test, pressure up to 4.5 bar close in a valve and leave for 30 minutes at least, the pressure may drop a minuscule amount but that is ok. Talking of working in oil and gas where i work there are regular 227barg nitrogen leak tests carried out by a specialist contractor but that is quite far removed from what the OP is doing

[pghstochaj]

samdale said:

Maybe it's just the industry you're in? I work in oil and gas and ~100bar nitrogen leak testing is common place. Important to note is how close this is to MAOP of the system. Typically our testing is at 90% of the relief valve set pressure. Occasionally at 110%.

That’s not really a pressure test then but a service test if it’s below the PRV setting as the piping stress will be designed a long way above the PRVs. For instance, our boilers operate at 80 bar on my current project and the hydrostatic pressure test was at 220 bar. PRVs on this operate at 100 bar.

Oil is a case where pneumatic testing is necessary to avoid contamination in lines. Turbine oil lines are the same for instance. My central heating system is not as sensitive to contamination with water!

[samdale]

pghstochaj said:

That’s not really a pressure test then but a service test if it’s below the PRV setting as the piping stress will be designed a long way above the PRVs. For instance, our boilers operate at 80 bar on my current project and the hydrostatic pressure test was at 220 bar. PRVs on this operate at 100 bar.

Oil is a case where pneumatic testing is necessary to avoid contamination in lines. Turbine oil lines are the same for instance. My central heating system is not as sensitive to contamination with water!

Semantics. I would call that a strength test. Usually carried out on individual pipe spools/vessels etc before installation. Once all valves/flanges etc are made up, a leak test is carried out. You don't want to be testing a joint to the same pressure you'd strength test the pipe at.

I work on a gas rig, the lines have plenty of sea water in them so not really a contamination issue.

[shady lee]

Woody3 said:

Finally started on this and so far so good. Told you that there would be questions, so...

I'm going to pressure test once complete. Going to pump it up to 10 bar for 2 min, then 2bar for 10 mins (and probably leave it over night).

Is it best to pressure test with the rads connected or should I cap off at the tails before the trv?

10bar!! Your boiler won't do more than 4 without the prv letting pressure off.

Just do 2 bar , if it's going to leak it will, trust me.