Jet Range by Wolseley - DN20 Isolation Valve

[ShaunCorbs]

Would need a pic

 

[Trevor Rix]

What pic would you like? Please see the two photos of the valve earlier in this thread.

 

[ShaunCorbs]

Where it was installed

 

[Trevor Rix]

In the yellow circle.

 

[ShaunCorbs]

That’s 22mm pipe so I would say not the parts fault the installers at fault

With it being 20mm it’s for alk eg watermains etc

What’s with the two flexis ?

 

[Trevor Rix]

So, are you saying that the installer is at fault for using a valve designed for use with 20mm alkathene on a 22mm copper installation?

I am guessing that the two flexibles pipes were used as an easy method of connecting the copper sections together? Looks rather Heath-Robinson to me.

 

[ShaunCorbs]

Correct it won’t fit as you’ve measured the hole is 20mm so must of been rammed in or something

Them flexis arnt rated for heating so best get them replaced

 

[Trevor Rix]

Thank you ShaunCorbs and everyone else who contributed. Much appreciated.

 

[Brambles]

Trevor,

DN20 is an ISO sized fitting for 3/4 inch pipe (26.66mm). It is not intended to be used with 22mm pipe. With respect to copper pipe it is intended for 3/4 inch outside diameter.

Normally if metric and imperial fittings are mixed up with 15mm and 1/2inch diameter pipe they generally work (not always). However the size difference between 22mm and 3/4inch is too great for success to be a possibility.

This would account for the pipe “popping” out - but I would be surprised that the pipe remained in place and leak free since the original installation - unless it had been “mumified” with ptfe tape!!

The Jet valve in question is a non return valve, the screw is for testing, it is not intended for isolation, there should be a proper (ball) isolation valve at the point of entry into the boiler house - the installer will have fitted one - he/she won’t have driven 1/2 mile to isolate the supply.

The flexibles look to be a makeshift filling loop. They should be replaced with the correct WRAS compliant ones.

If I were in your shoes, I would check out the system on a line by line basis, both for the design ( heat balance and flow calculations) and the specification of pipework and fittings / quality of installation work.

 

[Harvest Fields]

Trevor,

DN20 is an ISO sized fitting for 3/4 inch pipe (26.66mm). It is not intended to be used with 22mm pipe. With respect to copper pipe it is intended for 3/4 inch outside diameter.

Normally if metric and imperial fittings are mixed up with 15mm and 1/2inch diameter pipe they generally work (not always). However the size difference between 22mm and 3/4inch is too great for success to be a possibility.

This would account for the pipe “popping” out - but I would be surprised that the pipe remained in place and leak free since the original installation - unless it had been “mumified” with ptfe tape!!

The Jet valve in question is a non return valve, the screw is for testing, it is not intended for isolation, there should be a proper (ball) isolation valve at the point of entry into the boiler house - the installer will have fitted one - he/she won’t have driven 1/2 mile to isolate the supply.

The flexibles look to be a makeshift filling loop. They should be replaced with the correct WRAS compliant ones.

If I were in your shoes, I would check out the system on a line by line basis, both for the design ( heat balance and flow calculations) and the specification of pipework and fittings / quality of installation work.

So why could he not use a 3/4 olive?

 

[Chalked]

All sorts at fault here.
Wrong size valve fitted to 22mm copper. ( but would probably seal)
Wrong flexi pipes used as a filling loop. .
Fitter that had the problem thinking the non return was a service valve. Which he then unscrewed the Center. This would then have popped out, causing the main flood.
Looks like the OP is looking for blame, it it’s just a case of bad installation and a mistake by the guy investigating.

Remedy.
Pay the last guy to fit an approved filling loop.

 

[Trevor Rix]

"Which he then unscrewed the Center".

That was not the case. Nothing was unscrewed, or even touched on the valve, prior to the potential flood. The plumber said he merely removed the insulation around the valve for access when the pipe popped out of the valve.

The "last guy" working for the original supplier/installer/service was very much part of this issue as in giving me wrong information, and also much to blame regarding my other thread on this forum today.

 

[Trevor Rix]

The Jet valve in question is a non return valve, the screw is for testing, it is not intended for isolation, there should be a proper (ball) isolation valve at the point of entry into the boiler house - the installer will have fitted one - he/she won’t have driven 1/2 mile to isolate the supply.

Apparently the installer did not fit an isolation valve because they claim that would contravene the regulations that state that an unimpeded flow of mains water needs to be constantly available to quench/flood any serious malfunction in the ETA biomass boiler. An isolation valve could be closed manually accidentally. Hence the need to drive half a mile to turn off the supply at the incoming water meter.

 

[Trevor Rix]

I have had a detailed conversation with Wolseley/Pipecentre who are the suppliers of this Jet double check valve known as DZR.

He said this valve is still sold as a current product and does not have a design fault. He said the valve comes with universal ends that are intended to be used on various pipes including 22mm copper pipe compression.

As the 22mm copper pipe popped out of one end of the valve under mains water pressure, he said that the failure was due to incorrect installation by the plumber.

Does all of that make sense?

 

[Riley]

I think you’d do well to drag an admittance of design flaw out of them. Unless there is a product recall I doubt they would be obliged to admit to anything.