Air Compressor testing | Air Sourced Heat Pumps | Plumbers Forums

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Discuss Air Compressor testing in the Air Sourced Heat Pumps area at Plumbers Forums

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jase158

Hi All
I am looking to purchase an air compressor to test installations, I have seen the one I want and I am happy that finnaly I can test the pipework before I put water through it, Now I have no idea on how to connect these to the pipework, the plumbfix magazine says you can get 1/4 " connection for it, however, I have no idea what this will fit to, any ideas please,

also anybody know if i should disconnect the boiler, hot water and cold water tanks and the F&E tank.

My guess is that they all need disconnecting, but anybody with any experience, please let me know
 
How can you pressure test a system which is open to the atmosphere? of course you need cap the open vent and cap the feed.

1/4" male or female to copper what ever fits the compressor

Be careful what pressure you take the systems up to!
 
pressure test is on pipework only and i am also interested in getting a machine what one have you got your eye on??
 
I have used one for years,you I got a shraeder valve from the local tyre shop and drilled out a radiator bleed fitting and inserted the schraeder valve , I then fitted the 1/2 inch rad bleed valve into a 15mm M/I and onto this had a short section of 15mm pipe with a speedfit isolator and then a T with a PRV gauge and then onto a speedfit socket which will go onto your pipework to test, the isolator is closed when you have the system up to pressure and the schraeder valve is used to fill the system with air. Works a treat.
 
"the reward for work well done is the opportunity to do more. you're only as good as your last job"

love the saying, but does that me if you do a bad job, you should stop, lol
 
"the reward for work well done is the opportunity to do more. you're only as good as your last job"

love the saying, but does that me if you do a bad job, you should stop, lol

Just always do your best to do a good job always think would I like that in my own house
 
We've always used a cheap compressor to test systems. I make up a simple rig that has a guage (don't trust the one on your compressor) and two lever arm valves, One to lock the pressure in and another to release it in a controlled manner. Very simple to knock up.

Points to note: Water doesn't compress, and air does, therefore if a fitting did go, for instance a speedfit cap, it will go with a considerable PING. Make sure you won't be in the way if it did go.

Also don't over charge the system, very easy to turn around for a second, look back and the whole lot might have jumped to 8bar or whatever.

Don't attach things like expansion vessels, and cylinder coils to your test. As said, they are factory tested, and you'll do more harm than good.

I bought my latest compressor (last one was nicked in January) from Tool station. Cost £100 and came with a load of bits that I'll never use, but are useful for producing said rig.
 
Here's the same rig, used to pressure test reclaimed column radiators on a period install job. The part spurting water is a female 3/8 BSP, which with a bit of PTFE will accept a compresser hose union perfectly.
IMG_3023.jpg
 
Thanks Danny pipe,
has anybody had any experience with these?
http://www.*************/p/monument-dry-pressure-test-kit/72940?cm_mmc=GoogleBase-_-Datafeed-_-Tools-_-Monument%20Dry%20Pressure%20Test%20Kit

seems a lot simpler to me? although, simplicity aint always a good thing.

does anybody know the maximum pressure, I know most things are different, i.e. solder fittings, pushfit,
but most houses have a mixture, so what would be the highest reccomended pressure.
The house has a prv so the maximum pressure is 4 bar so the test would be 6 bar. but what if the house was 6 bar for instance the test would need to be 9 bar, very worrying at that pressure.
 
You should really turn them off, but in all honesty, I never do, and it's useful not to because it will show up if a rad valve union is leaking or you've left a bleed valve open.

So in short, yes check the rads as well as the pipe work. I've done it for years and never had a single problem. It can save you hours on a drain down too. I only bother checking large runs of pipe. Not worth the hassle of setting it all up otherwise.
 
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Oh and Jase, your link doesn't work, but I think I know without looking. No not ever used one. My little rig is perfect. If I lose it, I make another one, and it's quicker than a shrader connection.

Pressure, I normally go up to about 1.5/2 bar. Going to 9 bar would be silly, and over the top. You're on the hunt for obvious leaks. Not things that will only go at 9Bar!!
Besides if it leaks, it will leak at 0.5 of a bar, so going up to such a dangerous pressure is not really helping you.


If a speedfit cap came off at 9bar and hit some one, they'd probably be going to hospital.
 
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Oh and Jase, your link doesn't work, but I think I know without looking. No not ever used one. My little rig is perfect. If I lose it, I make another one, and it's quicker than a shrader connection.

Pressure, I normally go up to about 1.5/2 bar. Going to 9 bar would be silly, and over the top. You're on the hunt for obvious leaks. Not things that will only go at 9Bar!!
Besides if it leaks, it will leak at 0.5 of a bar, so going up to such a dangerous pressure is not really helping you.


If a speedfit cap came off at 9bar and hit some one, they'd probably be going to hospital.

So you are testing for a drop in normal working pressure, in college we got told to test for 30 minutes at 1.5 times working pressure for 30 minutes and then normal working pressure for 60 minutes.

I think yours way makes more sense, Is air testing 100% fool proof or have you tested a run before and got no drop and when you put water through, you get a leak?
 
Yeah what they teach you at college is all well and good, but follow it all like gospel and you'll probably end up causing yourself unnecessary grief. Its a good grounding but common sense and doing it in a way that works best for you is the thing to do.

Yes I've had joints pass an air test, and fail with the real thing. However its normally a weep rather than a spurt!! Perfect example is on the last install we did.

The apprentice had wound the unions in the rad too deep. They passed the air test but dripped upon filling up.

An air test will save you lots of hassle with obvious things, but there is no substitute for a proper water test. I also have the gear to over pressurise the system wet with a hydraulic pumped tester. However I only use this on underfloor heating circuits. I pressurise the system up, and leave it pressurised while the screed is being laid. This helps for two reasons.

1/ You'll notice if someone puts a hole in the pipe (water everywhere and the needle on the guage will drop like a stone).
2/ The plastic pipe expands with pressure, so you want it in an expanded state while the screed is laid (and dries) to prevent it cracking later.
 
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if you get a tubeless tyre shraeder valve and squeeze into a 15mm comp nut this works.
then get one of these,
18V RECHARGEABLE AIR COMPRESSOR 2 BATTS TYRE INFLATOR | eBay UK

you will find it is exactly the same as the rothenburger one and others, just re-packaged.
the added value to this one it is 18v with 2 batteries not 9v like the others.

ps. dont know what the price is doing at £1k, but last time i looked it was £30.
 
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Hi All

Just to let you know, I got the compressor, £99 from Screw fix, 8mmx15mm reducer, pressure gauge, 2x isolation valves and connected the hose to the 8mmx15mm reducer, then connected up the pressure gauge with the isolation valves. and it worked a treat. now the property is all working and I know that there aint no leaks, plus I now know that my work aint as bad as it sometimes feels. (plumbing can be depressing when you are just about to leave at 7.30pm and you see water dripping from 3 different joints)

Thanks everybody for your help.
 
Well done Jase. That little rig will stand you in good stead for years to come. Find one dodgy joint with it and it will have earned its money, as you won't have all that draining malarky to contend with.

PS - You leave at 7.30pm.....good on you. I like to make sure I'm all wrapped up for 2pm and in the pub for ten past. :) :) :) Would be nice though!
 
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