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Discuss Pressure test JG Speedfit? in the Plumbing Jobs | The Job-board area at PlumbersForums.net

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Hi all, I’ve just installed a two pipe central heating system and need a pressure test. However JG require a wet test at 2 bar then at 10 bar with the pipe disconnected from the rads and boiler.

I should have probably thought about this earlier but I can’t think how I’m going to fill the pipes and purge the system if I can’t connect them to the rads? I wouldn’t have thought the TRVs and locksheilds could withstand 10 bar pressure?

Do I need to put stop ends on all the rad tails, fill with water then test? If so I’m sure il have air in the tails?

Sorry if I’m being thick!!
 
Link the pipes together

But tbh if it's already connected to the rads test them upto 5 bar
 
As ShaunCorbs says, link them together.

I'd test them to 10 bar, as this may well be the pressure required to make the grip rings grab the pipes firmly, which might be a warranty issue in the event of later failure.
 
Dont think I would be pumping it up to 5bar with the rads fitted ??? you will need to remove them and link the flows and returns you can then fill through the filling loop isolate the boiler on its valves dissconnect your filling loop and connect your pump there shouldnt take much as the pipework will be full . Kop
 
Couldn’t you just turn all the rads lockshield and TRVs off fully and with boiler also isolated just use filling loop if bypass valve is on system and open, so linking flow and returns?
 
Thanks for the replies.

I think I’m with KOP not sure about pressure testing rads to 5 bar? Is that recommended? Plus JG require 10 bar test and I definitely don’t want to put 10 bar through them..

If I link the feed and returns, surely water will just take the easiest path ie only fill the first couple loops and i’ll end up with a load of air at the end of the index loop? How would I ensure there’s no air traps? Or would a small part of air not matter too much?

Is there a standard approach people use?
 
You could first fill the system to a couple of bar and bleed the radiators etc.
Then isolate the radiators and boiler from the system and put pressure higher if flow and returns are connected somewhere.
I think most radiators have a working limit of 3bar.
 
Thanks Best, I could easily put a temporary link between flow and return and having rads in place would make it easy to bleed then shut off on the locksheild and TRV to only pressure test the pipes. I could isolate the boiler as well then pressure test from a tee. However do you think the TRVs would be able to cope with 10bar for 10 munitues? Don’t want to damage them?
 
Thanks Best, I could easily put a temporary link between flow and return and having rads in place would make it easy to bleed then shut off on the locksheild and TRV to only pressure test the pipes. I could isolate the boiler as well then pressure test from a tee. However do you think the TRVs would be able to cope with 10bar for 10 munitues? Don’t want to damage them?

Need to check the MIs of your TRVs, but some are rated for 10 bar
 
20 bar test pressure apparently! That’s a lot more than I thought.

https://www.plumbase.co.uk/link/1/h013782_28484_t.pdf

Thanks for the help all.

20bar? Not for the JG. 10 bar max IIRC.

One thing to be wary of: you must purge as much air as possible. 1) It will take forever to pressurise a dry system; 2) More importantly, 10 bar of several dozen litres of compressed air is extremely dangerous in terms of the energy stored. A wet test, a fitting falling off is likely to do just that, fall off. A dry test, it will probably take out a window.
 
20bar? Not for the JG. 10 bar max IIRC.

One thing to be wary of: you must purge as much air as possible. 1) It will take forever to pressurise a dry system; 2) More importantly, 10 bar of several dozen litres of compressed air is extremely dangerous in terms of the energy stored. A wet test, a fitting falling off is likely to do just that, fall off. A dry test, it will probably take out a window.

Thanks Tim, it’s the TRVs that can take 20bar hence the link, yes the jg is 10bar for 10 mins according to the website. How would you recommend purging the system if the feed and returns are linked with the rads removed as KOP suggests?
 
Thanks Tim, it’s the TRVs that can take 20bar hence the link, yes the jg is 10bar for 10 mins according to the website. How would you recommend purging the system if the feed and returns are linked with the rads removed as KOP suggests?

If you have the boiler feed and return available, I'd try connecting one to a hose outside and the other to a hose on the garden tap (or any other tap) and purge it with mains water pressure. Did that on my UFH loops the other week (via the drain cocks). When you bridge the radiator connections as suggested, I would include a temporary valve that is rated at 10 bar - even a cheap isolator valve - pop it onto some scrap copper and plug the JG onto that if you can't find a cheap pushfit version. Close all off, then open one, wait, close, move to next radiator position and I would have thought that should flush most of the air out.
 
Thanks for that post Tim, that’s what I was after. It’s going to be a bit of a pain though... il have to buy some more pipe and fittings.

Off to screwfix for the 25th time this month!
 

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