Are those cheap (B&Q, etc) white plastic push-fit end-caps reliable on
15mm copper pipe in a gas-fired domestic central heating system? I
just removed a radiator and used these to cap off the feed and return
pipes. I was alarmed when I saw how easy they push on and pull off by
hand. Has anyone known one to work loose? The pressure of my system
goes up to 2 bar.

Thanks..

Al

Al  wrote:

> Are those cheap (B&Q, etc) white plastic push-fit end-caps reliable on
> 15mm copper pipe in a gas-fired domestic central heating system? I
> just removed a radiator and used these to cap off the feed and return
> pipes. I was alarmed when I saw how easy they push on and pull off by
> hand. Has anyone known one to work loose? The pressure of my system
> goes up to 2 bar.


1 bar = 1Kg/m^2 of pressure.
2 bar = 2Kg/m^2 of pressure.
15mm pipe has an area a bit more than 1 square centimeter, so you're probably
looking at a force of around 3Kg.
Obtain a 3Kg weight, and compare the forces.

"Ian Stirling"  wrote in message 
news:4324a6ac$0$17492$ed2e19e4@ptn-nntp-reader04.plus.net...

> Al  wrote:
>> Are those cheap (B&Q, etc) white plastic push-fit end-caps reliable on
>> 15mm copper pipe in a gas-fired domestic central heating system? I
>> just removed a radiator and used these to cap off the feed and return
>> pipes. I was alarmed when I saw how easy they push on and pull off by
>> hand. Has anyone known one to work loose? The pressure of my system
>> goes up to 2 bar.
>
> 1 bar = 1Kg/m^2 of pressure.
> 2 bar = 2Kg/m^2 of pressure.
> 15mm pipe has an area a bit more than 1 square centimeter, so you're 
> probably
> looking at a force of around 3Kg.
> Obtain a 3Kg weight, and compare the forces.


I think you mean 1 bar = 1kg/cm^2, non?!

Andy.

Andy  wrote:

> 
> "Ian Stirling"  wrote in message 
> news:4324a6ac$0$17492$ed2e19e4@ptn-nntp-reader04.plus.net...
>> Al  wrote:
>>> Are those cheap (B&Q, etc) white plastic push-fit end-caps reliable on
>>> 15mm copper pipe in a gas-fired domestic central heating system? I
>>> just removed a radiator and used these to cap off the feed and return
>>> pipes. I was alarmed when I saw how easy they push on and pull off by
>>> hand. Has anyone known one to work loose? The pressure of my system
>>> goes up to 2 bar.
>>
>> 1 bar = 1Kg/m^2 of pressure.
>> 2 bar = 2Kg/m^2 of pressure.
>> 15mm pipe has an area a bit more than 1 square centimeter, so you're 
>> probably
>> looking at a force of around 3Kg.
>> Obtain a 3Kg weight, and compare the forces.
> 
> I think you mean 1 bar = 1kg/cm^2, non?!


Yes.
I'd claim a dodgy c key, but it was simply not thinking while typing.

On Sun, 11 Sep 2005 21:04:41 GMT, AL205refirst@phoneyaddy.com (Al)
wrote:


>Are those cheap (B&Q, etc) white plastic push-fit end-caps reliable on
>15mm copper pipe in a gas-fired domestic central heating system? I
>just removed a radiator and used these to cap off the feed and return
>pipes. I was alarmed when I saw how easy they push on and pull off by
>hand. Has anyone known one to work loose? The pressure of my system
>goes up to 2 bar.
>
>Thanks..
>
>Al


Did you push them on far enough? I'm currently replumbing a load of
radiators using hep2o (http://hep2o.co.uk/) and you certainly can't
pull those connectors off by hand, but it takes a bit of effort to
push the pipe far enough into the connectors.

Being able to pull plumbing apart by hand doesn't sound right to me!

Mr F.

> I was alarmed when I saw how easy they push on and pull off by
> hand. Has anyone known one to work loose? The pressure of my system
> goes up to 2 bar.


No problem with them on copper. However, if you can pull them off again,
then you either aren't pushing them on enough, or the joints have been
misassembled, so the grab ring is ineffective.

Christian.

On Sun, 11 Sep 2005 21:04:41 GMT, AL205refirst@phoneyaddy.com (Al)
scrawled:


>I was alarmed when I saw how easy they push on and pull off by
>hand. Has anyone known one to work loose? The pressure of my system
>goes up to 2 bar.
>

They generally do pull on and off easily by hand when there is no
pressure behind them. IME, once you refill the system the endstop is
unmoveable as the pressure locks it into place.
-- 
Stuart @ SJW Electrical

Please Reply to group

Thanks to all who responded. After reading your comments I found I
could push them on a further 5mm than I had realised. Hopefully they
will now hold! Many thanks!

Al

> Thanks to all who responded. After reading your comments I found I
> could push them on a further 5mm than I had realised. Hopefully they
> will now hold! Many thanks!


You'll probably find the first "click" is the O-ring, which provides the
seal. The second "click" is probably the lock ring going onto the copper,
which stops it coming apart.

Christian.