Pressure testing radiator pipework

[Jupiter01]

can someone please send me a picture of the vent I can connect to 10mm hep20 pipe or 22mm copper pipe.

 

[Jupiter01]

Can someone please send me a picture of the vent being discussed above? Thanks

 

[Jupiter01]

can someone please guide me in the type if vent I should be using. Thanks in advance

 

[Madrab]

Several ways, 8mm pipe to 15mm reducer and then an ISO valve
Manual air vents - I have a set of manual air vents made up on 15mm copper with compression ends
Use stop ends - just pump until water is at the open end then pop the stop end on.

 

[Jupiter01]

Thanks @Madrab.
That's very helpful. A couple of questions please.
- If I stick an isolating valve on one of the open ends, will that be fine to release air as well? I assume it will as per your post but didn't know whether air releasing requires a minimal opening capacity like the type you have on a radiator vent
- With the Rothenberger Pressure Tester, what type of fitting does it have? I will want to connect to 22mm copper

 

[dilalio]

The system being tested doesn't need to be completely full of water. Put a pressure gauge on it and pump it up to relevant pressure and mark the gauge with pen or the red indicator that most have... Leave it for the day (or overnight if you can) and any drop will register even if it's air escaping!

 

[Madrab]

Yes, an ISO can be used, no bother there.

Some if not all come with 1/2" BSP female connectors

 

[Jupiter01]

thanks. Does 8 bar seen sufficient?

 

[Jackrae]

For a system running at a maximum of 3 Bar I'd reckon 8 for a test is excessive (4.5 should be sufficient sufficient)

 

[Jupiter01]

Thanks @Jackrae. What's a realistic test duration please? I only ask as I have 2 separate zones to test and obviously a flow and return within each. That's 4 tests unless it makes sense to combine the flow and returns for each zone?

 

[Jackrae]

You want to couple all zones including flow and return together as a single test otherwise any weeping past zone valves will screw up your test results.
Providing the system has no air in it then as others have said, a couple of hours should reveal soundness. However if there is substantial quantities of trapped air then you may have to extend the test period. On a large system a small weep will not show as a drop in pressure during a short duration test if there is air entrained in the pipework, hence the need to get all the air out for the test.
Again you want to do the test with reasonably stable air and water temperature since a decrease in either's temperature will show up as a loss in pressure and vice versa.
Ideally you need to be able to inspect all joints and use some blue hand drying paper to check joints if you suspect leaks. The blue paper shows up any weeps much better than white as its colour change to darker blue when wet is quite evident.

 

[Jupiter01]

At the moment I have two separate set of flow and returns (upstairs and downstairs). I have laid these pipes. Everything else will be done by the plumber, including the zones. I just want to test all my pipework in advance of the plumber doing his piece.

I assume in this situation I am okay to test each zone (flow and returns) individually i.e. 2 tests: 1 for upstairs zone and one for downstairs. This also means that I don't have to spend a fortune on Hep20 end caps for my 10mm down pipes (!!!) as I can demount and reuse across zones.

Thanks for the tip on blue paper.