Speedfit isolation valves - ok for Mains and hot?

[Doctor Drivel]

Use compression Avoid pushfit. Too many problems with these. Compression is easy.

[Doctor Drivel]

You are a very lucky man.

Oh he has now.

[Doctor Drivel]

The chlorine in a secondary circulation loop attacks the plastic.

Yep.

[Steve Firth]

Ignore Drivel. His bad opinion of pushfit is based entirely on his inability to read and follow instructions.

[Steve Firth]

Whereas compression fittings are held by one little bit of metal. I'll take the laugh option, thanks for the offer.

[Steve Firth]

The reason is given in the Speedfit product guide (p 38), commercial ring mains have constant temperatures higher than 65C which is outside the operating range of Speedfit pipe and fittings. However domestic ring mains which have intermittent temperatures lower than 65C are OK with Speedfit.

[David Hansen]

On Wed, 21 Feb 2007 02:36:55 +0000 someone who may be Steve Firth wrote this:-

Incorrect, they are held by two large bits of metal, the nut and the thread on the end of the fitting. Far more solid than some little metal springs.

Thanks for playing.

[Doctor Drivel]

He is not playing, he is actually serious. He does think knows about it.

[Doctor Drivel]

You must eff off as you are a total idiot.

[Doctor Drivel]

Please eff off, it is clear you are an idiot.

[Steve Firth]

No, you fail to understand how compression fittings work. The only thing stopping the pipe from releasing is the olive. If the nut is secured but the olive is not compressed then the joint will fail. It's that one small piece of metal that makes the joint.

Thanks for proving that smugness is no substitute for knowledge.

[stevep]

I have made a decision and should like to thank you all again for your help.

I've opted for a set of compression fit full-bore ball valves. These might be overkill compared to standard compression fit isolation valves but the price was good and I can use the spare ones elsewhere. Also, having handles on the valves rather than fiddling about with a screwdriver certainly appeals.

Not that I'm knocking pushfit. I will likely be using at least one in an awkward area that will be a bit difficult for spanners. Speedfit is on the list given its additional twist-and-lock feature - got to be more secure.

All the best everyone. Steve

[Jim Alexander]

yes, but not sure every part is twist and lock yet but if not use a collet clip for extra security.

Jim A

[David Hansen]

On Wed, 21 Feb 2007 11:42:24 +0000 someone who may be Steve Firth wrote this:-

Incorrect.

Correct, but the olive is compressed (and held so that it does not come out of the fitting) by the two large bits of metal that are the nut and the threaded part of the fitting. The olive itself is also a large bit of metal, unlike the little springs in a pushfit joint.

Under those circumstances the joint will fail instantly. It will not suddenly fail in a week or a month.

Excellent, another personal attack.