Full bore pushfit isolation valve

[CoxHQ]

Hello, I'm using JG Speed fit in my bathroom, will there be a noticeable drop in pressure if I use their isolation valves on the shower etc? Their valves aren't full bore according to screwfix. If so what would anyone recommend?

Thanks in advance.

 

[blup]

It depends on the water pressure, whether it's from hot or cold supply, whether it's pumped, competing calls on water, etc etc.

Less likely to be an issue if it's a cold fed mains pressure electric shower.

The restriction on bore is often specified, and can vary, so this is a factor too.

Location permitting, I replace my isolation valves with full bore Pegler 1/4 turn ball valve when the opportunity arises, having had several gate valves fail through seizure and rusting.

Blup

 

[CoxHQ]

Thanks for the quick reply Blup. The mains pressure is decent, there are no pumps involved and the hot water comes from a combi boiler. JGSpeed fit say "The through bore in a 15SVP is 9.5mm".

The valves will be behind the bath panel so no problems with access. Can I use compression fittings on plastic pipe?

 

[Elkato531]

You can use compression fittings on plastic but don't forget the pipe inserts. Avoid the plastic pushfit isolation valves as they are crap.

 

[SandyLyon]

You can use compression fittings on plastic, always use a pipe insert, better to use copper olives rather than brass and DON’T use any jointing paste. If you need to you can use PTFE tape.

Hep2o make a range of Full Bore metal bodied 1/4 turn lever isolating valves, not particularly cheap but top quality.

 

[CoxHQ]

I’ll get some decent full bore compression fittings for bath, basin and toilet. Thanks for your help.

 

[winston1]

If you need to you can use PTFE tape.

PTFE tape is NOT needed on compression fittings whether plastic or copper.

 

[blup]

As said pipe inserts are needed.

Shouldn't use PTFE on compression fittings, and certainly not on plastic, the water pressure will encourage the fitting to part company with the pipe.

Blup

 

[ReX83]

Resuming a very old thread, but hopefully someone is still interested...

I was about to upgrade few isolation valves, replacing with full bore valves when I made the awkward discovery that the plastic pipe inserts have exactly the same diameter of the existing valves.

So my question is: what is the point of using full bore valves in a plastic pushfit installation that anyway has plenty of inserts?

The other question is: on a 22mm/15mm installation with good pressure and combi boiler, am I going to see a reduced flow rate due the partial bore of valves and inserts?

Thanks

 

[StopHammerTime]

Resuming a very old thread, but hopefully someone is still interested...

I was about to upgrade few isolation valves, replacing with full bore valves when I made the awkward discovery that the plastic pipe inserts have exactly the same diameter of the existing valves.

So my question is: what is the point of using full bore valves in a plastic pushfit installation that anyway has plenty of inserts?

The other question is: on a 22mm/15mm installation with good pressure and combi boiler, am I going to see a reduced flow rate due the partial bore of valves and inserts?

Thanks

Push fit inserts, or at least hep20 ones ,are not the same diameter as Normal isolation valve bores. Full bore allows more flow.. They are about 2mm narrower in diameter , if not a little more-they are a surprising reduction though. However you’ll notice more flow rate reduction in all the elbows used due to the nature of plastic pipe, try to make that up where bending is possible .

 

[ReX83]

The no-name products used at my house (sold by Toolstation) have inserts without o-rings with an inner diameter equal to the non-full bore valves from the same series. I wanted to upgrade to full bore valves from another brand, but I think it is pointless, as anyway the bottlenecks are the inserts.

Thanks for the tip about elbows - I never appreciated the extent of the diameter reduction.

 

[Keithmac]

Sounds pointless to fit full bore valves if your inserts are already restricting the flow?.

 

[ReX83]

Sounds pointless to fit full bore valves if your inserts are already restricting the flow?.

I agree - I came to the same conclusion.

 

[HERTS P&D]

The only thing is, full bore valves are better quality, easy to turn and don't leak.

Andy

 

[StopHammerTime]

The no-name products used at my house (sold by Toolstation) have inserts without o-rings with an inner diameter equal to the non-full bore valves from the same series. I wanted to upgrade to full bore valves from another brand, but I think it is pointless, as anyway the bottlenecks are the inserts.

Thanks for the tip about elbows - I never appreciated the extent of the diameter reduction.

Ah, I was tempted by their no-name stop ends at the weekend but the reviews put me right off. I stick with Hep2O and it's been good to me..apart from the pricetag.

I've been aware of angles reducing flow for a while but I recently redid a kitchen where the predecessor didn't own a pipe bender so the pipework resembled a rubics cube (they'd litterally created squares of pipework to eventually get it pointing the way they wanted) .There was a minimum of 12 angles used between stop tap and kitchen tap - I ripped it all out and now there are 2 angles (one on each h/c)and only pipe bends...I'm still getting used to the new found water pressure/flow! It was an amazing difference, previously hot water took ages to get there and was sporadic.

Sounds pointless to fit full bore valves if your inserts are already restricting the flow?.

That's like saying the speedlimits been changed to 50mph an hour I may aswell just do 40mph everywhere (which some people admittedly do!). On branded kit I've seen the inserts restrict diameter about 10% a normal isolation valve would restrict a FURTHER 10% (minimum).
So your options are 10% less than copper using full bore valves where needed or 20% less than copper using iso valves everywhere. (Unless you are referring only to Rex's non-brand stuff with the same diameter)


I hasten to point out, it's pointless putting fullbore valves directly below quite a lot of appliances as you will find a mixer tap, for instance, has a bore of about half of a pipe insert. I use full-bore valves where I isolate flow to a segment of the house, i.e I have a service hatch with full bore valves at every level of the house and on entry to the extension.
If you are unable to get an iso valve under every appliance in a room for whatever reason (sometimes shower pipes are innaccessible) and will be using one valve for both a sink and a shower for example I would fit a full bore valve.