Ideas for testing plumbing before covering

[Justme]

As per title I am looking for ways of testing my plumbing for leaks before I can fill it with water & so I can cover it up in the walls & floors.

Mainly need to test the rad system that has been done in 10mm copper but rads not fitted yet. I was thinking of fitting end caps to all open pipes & then some how fitting a schreader valve so I can pressure it with the compressor. Is there an easy way of doing so (or a better idea) & what sort of test pressure should I use & for how long (or should I just pressure it & test for escaping air using water / wash liquid bubble testing).

[Pat_]

Never pressure test using air! It is extremely dangerous because as air is so compressible a lot of energy gets stored, which can launch a loose fitting right through you. I bought a Rothenberger (lookalike) pressure tester (uses water) and have found it invaluable. I test at 3 Bar usually. The only think I don't like is that ou need to add your own pressure gauge if you want to read an accurate pressure that low.

see ebay 250686472109

[johnrae]

As a professional engineer I fully appreciate the dangers of air testing and would never recommend such a proceedure for pressure vessel testing.  However, the benefits of dry testing a domestic system under strictly controlled conditions can mitigate the risk, providing there has been the application of a little bit of common sense. 

Your idea of making up a test piece plus pressure gauge is sound, but do NOT use any form of motor driven compressor.  You need a source of low pressure, low delivery volume air.  Use a bicycle pump and pressurise to a maximum of 0.25bar (4psi) 

Because your plumbing is a low volume, distributed system rather than a single pressure vessel, a failure release will not be an instantaneous event since the tubing lengths will limit blow-off velocity and the low test pressure will quickly disipate.  Also consider that you are not testing the integrity of the pressure retention system. rather you are testing for installation failings.

The procedure will not be a proof test for your installation but will highlight any obvious oversights (leaking joints or missing olives etc)  Only a hydraulic test with water at operating pressure will fully test the system.  However, since you have conducted a controlled dry test you can be reasonably confident that there are no obvious ommisions.

jack

[Jonathan]

I noticed that Lidl are currently selling a garden spray that pumps up to 2.5 bar for 9.99. These sprays are commonly used once adapted for filling solar loops, so should meet your purpose well, both wet or dry.
Jonathan

[Justme]

Good idea with the sprayer. I have one & could use it dry to do the dry test & then follow with a wet test. Just dont want to wet test first in case I need to re solder / re make a joint.

[bram]

could you not just get a dry test pressure kit from the likes of screw fit 72940

[Justme]

could you not just get a dry test pressure kit from the likes of screw fit 72940

Blown the budget.

But must say I had not seen any that cheap. Still a lot for a few mins use.

Even cheaper HERE

[bram]

If you were a little closer you could borrow mine

[johnrae]

Some of you guys have money to burn

What's wrong with the bicycle pump idea.  You can borrow mine ( the test set using such a pump) if you care to come and collect it.
Costs practically ziltch to make using a push-on 15mm end cap and a schrader tyre valve from an old bicycle tube.
To measure/monitor the pressure you can use clear PVC tubing with a column of water in it (2.3 feet = 1 psi)

Cheap as chips and does the job.

jack

[wyleu]

Practically yes, but when the insurance company asks if the tests were done with certified instruments...

[johnrae]

And if you say the tool was bought from *****fix they'll still laugh 'cause it ain't certified either.

[Stuart]

does spoil the fun of running round with old towels though

[johnrae]

Not quite on the same theme, but I use my wet and dry vacuum cleaner when draining radiators for removal.  Simply place nozzle in vicinity of fitting and loosen off the union.

[Justme]

Thanks for all the offers & advice.

The problem is that once its filled the joints will be in the floor & as its a vented system that will fill its self I will have no way of knowing if its leaking till the floor rots away.

Will have a play with valves & fittings to see what I can come up with.

[Billy]

Before I stopped doing gas on boats I always did an air test before filling up with gas.  Just using a hand squeezer and manometer not a compressor or owt.  For fuel tanks I normally fill up with water and elevate the filling pipe and topping up with water to suit the required pressure in metres of water height.

Billy