Jet Range by Wolseley - DN20 Isolation Valve

[Trevor Rix]

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.

Do you consider that there is a design flaw?

 

[Riley]

That’s really neither here or there, I don’t tend to fit that brand so it’s kind of inconsequential. My point is though unless there is some product recall I think you would have to assume that even if it is of poor quality then the valve should be fit for purpose. Look at it this way I wouldn’t have thought that a company like wolsley would continue to sell a pipefittings known to have serious failure issues​

 

[Brambles]

Trevor,
A couple of points. I have never seen a properly installed heating installation that cannot be isolated from all the external services ( compressed air, water, oil, gas, electricity et al) at the boundary limits to the boiler house) . It is basic safety that applies to any process. The fact that a service (ie water) needs an unimpeded supply, does not mean that it is not to be provided with a means of isolation for serving or maintenance. It does mean that isolation should be designed to prevent accidental isolation.

With respect to quenching - it is highly unlikely that a large domestic or small commercial wood fired, coal, coke, straw or biomass boiler has any form of quenching system. If you inject even a small quantity of water into an operating boiler (at 900 degrees plus), you will probably get an explosion. As and when you get a tube leak in your boiler - as it ages, look inside to see the damage even a small amount of water entering through a pin pick hole causes. Some boilers have steam injection, but they are generally related to power generation facilities.

In an emergency situation a biomass boiler is controlled by:
venting steam whilst increasing the flow, reducing combustion air, whilst maintaining cooling air to the burners and shutting off the fuel source. Having said that, the majority of fire incidents occur downstream of the boiler in the storage area ( biomass chips have a tendency to self combust if stored incorrectly).

Your boiler may have an external fire protection system, but even that is uncommon in the boiler house of a large domestic / small commercial biomass boiler.

Apologies for the soliloquy - but any boiler and particularly a biomass boiler burning a variable fuel source should be maintained by someone who is fully conversant with how the boiler operates. If the boiler is set up and operated incorrectly, you will get slagging, that produces hot spots and the integrity ( and life) of the boiler will be compromised.

As for having someone tinkering with the system who cannot fit a compression joint - I would show him the door.

 

[Trevor Rix]

Thanks for your observations Brambles. Only the biomass boiler supplier/installer/servicer company have had anything to do with the system. The plumber in question works for them. The boiler is a ETA Hack 70.

 

[snowhead]

There's nothing wrong with that NRV.
It's suitable for both bsp 3/4, (DN20) using the external thread and 22mm with olive internally.

I've used hundreds of Jet fittings of that type.

The 22mm pipe wasn't pushed in far enough and or not tightened correctly.
If the 22mm pipe was available for inspection it would show the mark where the olive gripped, or failed to grip.

And there should be a mains cold isolation valve nearby, whether the boiler has quenching or not, for exactly the situation that happened.
The quenching is to stop fire if it's burning back into the fuel feed tube or fuel store, not to extinguish the fire withing the combustion chamber.

The flexis are on the filling loop so should be O.K as it's normally isolated.