Pressure Testing

[33ching]

I go to my garage a few nights a week to practice my soldering (sad I know) and it is quite good but in the real world are you better to pressure test before you turn the water back on if possible or will you be able to tell with experience if it is a good joint. I have not yet seen either of the plumbers I work with from time to time pressure test so is this due to experience. They may do it when I am not there!
If you have not pressure tested and you turn the water back on and you have a leak what should you do.. eg. dry the joint and heat it back up and add more solder or cut out the joint and add a new one.

Thanks.

 

[migoplumber]

any soldered joint that leaks should always be cut out and replaced in a dry enviroment. ive lost count of the times, ive just depressurized and resoldered with plenty of flux, sometimes it works. for the times it does,dont bother.

no experience can tell you if a joint is going to fail. if you have time and the inclination and want to be sure of not getting an insurance claim against you, then dry test first.


sometimes when i soldar a joint, i think that might not be good, and have now learnt the lesson of chopping it straight out and doing it again though.
it did take me 15 years, before i opted for this line of action, and has since then probably saved me 100 hours of extra work.

 

[dodge]

as a rule personally with vertical joints that i can drain i would try only once to re-solder,horizontal with water laying in pipe or refilling cut out,re-solder and try to fit compression joint so you can let out water if you have another leak

 

[stevetheplumber]

to be honest most of us know by experience that a joint has run the one that leaks is always the one you have that little doubt in your mind about
if you can drain it you can resolder if you cant its a cut out job
worst one ever was a 42 mm elbow tucked behind a boilersix inches below the drain of 3 pm friday afternoon
yes before you all shout i know the drain off should be the lowest point but mean while in the real world ........

 

[33ching]

Thanks guys, I will remember that. Looks like I will be buying myself a pressure testing kit this weekend to be on the safe side.

Just an add on to this are you better dry or wet testing.

Thanks

 

[heinz57]

I was taught to pressure test wet for copper/plastic and air test for drains and traps. I read a thread here a few weeks ago about more experienced guys who use a compressor to air test copper pipe (if i read it right). I'm curious to know how you would find a leak using this method. Smoke pellets in the pipe maybe? Water leaking is easy to spot on a new system, but air? unless it whistles maybe. Would love to get some more info here, cheers.

 

[Plouasne]

I was taught to pressure test wet for copper/plastic and air test for drains and traps. I read a thread here a few weeks ago about more experienced guys who use a compressor to air test copper pipe (if i read it right). I'm curious to know how you would find a leak using this method. Smoke pellets in the pipe maybe? Water leaking is easy to spot on a new system, but air? unless it whistles maybe. Would love to get some more info here, cheers.

Exactly the same way as you would test a gas service, either a special spray can or the old soapy water and a paint brush, (the old Brymay Mark 1 test has been superseded, by more modern technology )

 

[Liam - Trainee]

I was recently taught to build up the pressure in the pipes to a certain level, then leave it for 30/40min and if the pressure has reduced then you have a leak..

If the pressure did reduce then the harder task is trying to find out which joint is leaking!!

 

[kingkenny]

i have made a small testing device out of a car tyre yalve and a 15mm hep2o coupling,then i can use a twin cylinder footpump,i replaced the pressure gauge with one from a prv,and regularly use it to test up to 6bar,just go round the joints with a soapy water spray to detect leaks.

 

[kirkgas]

always better to test with water, there is a defined test criteria for plastic and metal pipes, found in Water Byelws Document and relevant BS doc