oilman said:
Crimping olives is NOT the way to seal the joint, in fact it is more likely to cause the joint to leak. What sort of pressure do you have on pipes that is going to cause them to blow off? If you have that sort of pressure, you should be using a different type of joint, and ALL the fittings, (taps, valves, water tank) would have to be rated to take the pressure.
The correct way to test the joints is to do a hydraulic test, not over-tighten it.
Hi oilman
Er, you seem to have replied to a couple of things I didn't write.
For example, I didn't mention sealing the joint - that's a different subject. Although, while we're on it, 1st hand experience is that crimping doesn't make joints leak. You've confused crimping with incompetence.
Do you replace every wrong fitting that you come across? I certainly don't, and I'd soon see myself on Rogue Traders if I did. I surmise that your hint is aimed at using soldered joints, but it really isn't practical to replace every 'incorrect' compression joint with a soldered one, is it? I'm asking rhetorically of course.
Nor am I talking about the rating of valves, taps and other devices and appliances. Nothing personal, but you seem to be stating the obvious there.
To answer your question about the sort of pressure, I'm merely talking about mains pressure. For example, at a recent job, the mains was so high that all the Hep fittings that I'd just installed actually creaked and visibly moved when the cold was put back on. Clear groungs for a limiting device, but there wasn't one there before I started, and the guy had leaks from all kinds of places in his Combi system.
Now then - tell me that you've never ever seen a compression fitting that had excused itself from the duty of staying put on a 15mm rising main? No? Maybe all the installations that you encounter were perfectly carried out? Or perhaps you just haven't seen enough action yet?
Whatever the cause of your strongly-held view, I think maybe an open mind is best in all circumstances.