Pressure testing - 1.5 bar enough?

[Dotty]

yer like testing your CH pipe work?? wet test do you wet or dry test for gas runs????

All will be revealed when you do your ACS. Learn to walk before you try running.

 

[tamz]

There is no requirement to pressure test any existing pipework when doing alterations.

 

[jas88]

There is no requirement to pressure test any existing pipework when doing alterations.

I think there's a requirement to do some testing when the job quoted for was "fit the new cylinder, and check all the existing fittings since we're worried about the higher pressure" though...

But, according to this guy, you can't tell if a fitting's going to fail by inspecting it (probably mostly true) or by doing a pressure test or other test (the bit I'm very doubtful about). Apart from anything else, if he'd responded to the brief with "you can't test, changing to UV means a risk your fittings will suddenly burst and flood the house hours, weeks or months from now without any warning", he'd have been told to install it somewhere much darker and less comfortable for him!

 

[lame plumber]

if he had hydraulically tested you system and it had burst during the test, flooding your ceiling as now, who would you be claiming off for damages, or would you accept the damage as you asked him to test the system fully?

 

[tamz]

Believe me there is NO requirement to test when doing alterations to existing systems. Fitting an an unvented cylinder is an alteration to an existing.
New systems are different and should be tested to 1.5 times the working pressure.

There is always a risk of increased pressure finding out any weak points in a system. Getting someone else to do it wouldn't have changed the result. You would have still had a burst.
I would have had you sign a disclaimer before the work started or it wouldn't have started.

 

[jas88]

Is it not much more likely that burst would have been during an air test, though, with the plumber right there to deal with it, rather than in a potentially empty house? Even the hydraulic test, surely better under more controlled circumstances (with limited water) instead of an uncontrolled high-pressure flow continuing for however long it took to find and fix!

That disclaimer would have been a deal-breaker: no installation. With hindsight, obviously a better outcome, but this guy and the bathroom fitter were far too keen to go ahead, plonk the thing in and scarper. (Even leaving the logbook/guarantee paperwork blank, which doesn't help!)

 

[lame plumber]

if a disclaimer was a deal breaker then most firms wouldnt offer to do the work for you!

 

[tamz]

Plumbing systems are tested hydraulically. Air tests can be dangerous and require proper risk assessment and control measures.

If a test was offered this would be at an additional charge and any failings that showed up (testing by its nature is destructive) also chargable. Would you have been happy for the work to go ahead at a greater cost (and potential cost) if he had offered that and explained why.

Disclaimers and terms and conditions are a necessary thing these days (such is the way of the world). I don't need the hastle.

 

[jas88]

Plumbing systems are tested hydraulically. Air tests can be dangerous and require proper risk assessment and control measures.

If a test was offered this would be at an additional charge and any failings that showed up (testing by its nature is destructive) also chargable. Would you have been happy for the work to go ahead at a greater cost (and potential cost) if he had offered that and explained why.

The job as quoted - and indeed as performed - did include air testing, albeit only done at 1.5 bar which was apparently not much use, and with no mention of any risks involved. (Should I be concerned that I was sitting one sheet of plasterboard from most of the pipes concerned during the air test they did do?!) If a joint had burst during the test, even water rather than air, fixing that would be fine, and presumably any damage that might result too - after all, that's the situation I ended up having to deal with anyway, except without the plumber present and without any warning before the ceiling started dripping.

Disclaimers and terms and conditions are a necessary thing these days (such is the way of the world). I don't need the hastle.

Really, that's the bit I'm angry about. If I'd been told, say, "pressure-testing this properly will cost an extra £100, and might burst a pipe/joint, in which case that pipe/joint will need replacing" would be fine. Equally, being told it would cost £1000 to test and might mean a £10,000 repair bill would have been fine, though of course that one wouldn't go ahead.

If they'd just done the air test they did do at a higher pressure, like the 1.5 x 3 bar for new work instead of the 0.5x they used, am I right in thinking that would probably have caught the weak fitting which failed at 3 bar?

 

[tamz]

No one can say. It may have held up to a test ok as it did take a fair bit time before it came apart.
One of the downsides of plastic is when it leaks it is a big one rather than a drip.

 

[jas88]

You have a point there I suppose, having held up to 3 bar for 2 hours, it could well have held 4.5 for a few minutes and passed the test anyway...

Having just realised there was only six feet of air and nothing else between me and one of the plastic pipes under test, with hindsight and having seen your mention of danger, perhaps I should be happier about their use of low pressure! (Most of the pipes were above my head, with plaster in the way, but one ended in an open cupboard a few feet from where I sat, since your post was the first mention I've seen of any danger involved.)

Now you've piqued my curiosity about risk assessments and control measures, though - how should the air test have been done?

 

[tamz]

Ha If i tell you i would need to kill you :lol:

 

[tamz]

This will give you an idea

http://www.ukcopperboard.co.uk/literature/pdfs/Installation-Tips/Pressure-testing-piping-systems.pdf

 

[jas88]

This will give you an idea

http://www.ukcopperboard.co.uk/literature/pdfs/Installation-Tips/Pressure-testing-piping-systems.pdf

Thanks, interested reading - and a little worrying...

No more problems since Saturday (unless demanding an extra £160 to fill in the cylinder's logbook/guarantee paperwork counts!), which I'm hoping means it's all OK now.

The starting point was the need to get a second shower working on the far end of an ~ 8 foot run of 17mm copper under the floor. Rather than replace the copper - the floorboards were already up anyway - this guy suggested a UV cylinder as an alternative. The builder/plumber doing the shower room and I both had concerns about the existing bits, particularly the bathroom B&Q had fitted a few years earlier (the bit that leaked an hour after this plumber left!), so the job he was to quote for was changing to UV and checking/testing the existing fittings and the new bit. (Obviously, no mention at all of any danger or risks involved with testing; no mention of the air test until after the leak happened, just assurances the fittings had been checked and were all fine.) After it failed, they said the problem fitting was white rather than blue, which sounds like something you'd identify by looking at it?

How would you have done it? Swap the 17mm for something heftier and use a power shower (which had been the plan before the boards came up and the 17mm copper was visible)? (The pipe's perpendicular to the joists, which is a bit of a pain.) Go ahead with the UV cylinder?

 

[lame plumber]

wasnt leaking when he left, what more can you expect of a plumber. B&Q and their fitters are the ones to blame imho.

 

[jas88]

wasnt leaking when he left, what more can you expect of a plumber.

Honesty!

When specifically asked if the existing fittings would cope with the much higher pressure, the plumber recommending it could have given one of the answers others have posted here, that it's not possible to be sure, or that being nearly-sure risked causing a water leak in itself - instead, he said it would be fine and that he'd check the fittings could cope as part of the job. Not the slightest suggestion of any risk involved, quite the opposite. That, legally, morally and IMO professionally, is where he screwed up badly. (As he has since admitted, to be fair, and done what he can to put it right; after a little lawyering, it sank in that both parties had had a narrow escape.)

I would be grateful if someone could clarify their explanation about white v blue fittings, which sounds like something immediately obvious with even a brief glance at the fittings they were supposedly checking as part of the job quoted for. I posted this question here because they were hiding behind their 1.5 bar air test as being enough to support their assurances; as a physicist that sounded like nonsense, so I wanted the plumbing view. (It sounded to me a lot like "I tested this car's brakes at 30mph, so it must be fine for motorway use", "this extension cord's tested for 110V at 15 amps, so I'll use it for your 30A 240V ring main and hope it's OK"...)

B&Q and their fitters are the ones to blame imho.

They did a poor job*, perhaps, but their work held up fine as installed for years: it was only after this outfit made the change they'd promised would be OK that there was any problem. Legally (per Trading Standards lawyer), B&Q are off the hook there unless the "white" fittings (whatever those are) are actually prohibited for plumbing use: the increased pressure is a 'novus actus interveniens', not to mention this outfit's breach of contract by not even glancing at the fittings. Tell a customer about a risk and make sure they understand and accept it, that's one thing: sell them something and promise you'll do something that avoids the risk you ignored and they asked about, you are in for a whole world of pain when you let them down.

I had eye surgery last year. There was a detailed consent form explaining the risks and possible side-effects or complications (as standard for medical procedures), and I discussed the risks and how they would be reduced and dealt with if necessary beforehand. It wasn't a perfect outcome - but they didn't promise one, and did take the appropriate steps we'd discussed beforehand to address them. When you risk flooding a customer's house, potentially causing structural damage and tens of thousands of pounds of damage, shouldn't you tell the customer first?! The plumbers on this thread all seem to agree on that point at least.


Bottom line: shouldn't getting paid to "check those fittings, particularly the bathroom ones" involve at least seeing them? Wouldn't a proper plumber admit to the risks of much higher pressure when asked?

* It included fly-tipping in the garden: dumping a used bathroom suite from their previous job round the corner, to pick up later and save on disposal fees, as well as breaking a phone socket. Not impressive stuff, but at least the ceiling was still dry afterwards, unlike this unvented cylinder fiasco.

 

[lame plumber]

best you can do now is to replace all the shoddy fittings and pipework as youll never know if its going to fail in the future