John Guest ?

[Millie Master]

The problem I have with any larger size tube is the actual capacity of water it holds.

It doesn't matter so much with the cold water pipes but when it comes to the hot water supply, it stands to reason that larger diameter pipe waste so much water when you turn on the tap and have to wait for the hot stuff to arrive at it!
For this very reason I fitted 10mm pipe throughout which the Surflo pump works with very well indeed with lots of pressure and more than adequate flow at the tap.

Phil

 

[trevskoda]

The solid red and blue 12mm plastic pipe widely sold for caravan / campervan water seems to be the same stuff (nylon?) as industrial air hose.

Thats what i thought but maybe chems used in construction are not same,who knows.

 

[Vicdicdoc]

The problem I have with any larger size tube is the actual capacity of water it holds.

It doesn't matter so much with the cold water pipes but when it comes to the hot water supply, it stands to reason that larger diameter pipe waste so much water when you turn on the tap and have to wait for the hot stuff to arrive at it!
For this very reason I fitted 10mm pipe throughout which the Surflo pump works with very well indeed with lots of pressure and more than adequate flow at the tap.

Phil

~~~~~~~~~~~~~~~~
Phil, before I go get GJ piping & fittings can you tell me if 10mm is sufficient to give a good flow to the taps (kitchen & shower) using a Shurflo pump in my van?
Vic

 

[Millie Master]

~~~~~~~~~~~~~~~~
Phil, before I go get GJ piping & fittings can you tell me if 10mm is sufficient to give a good flow to the taps (kitchen & shower) using a Shurflo pump in my van?
Vic

Hiya Vic; yes I can assure you that just as long as you have a decent pump such as the Shurflo.................. you will get a good powerful flow.

We only on soak/off wash/on rinse shower to save water and the power of flow at the shower head is way more than adequate, in fact neither of us ever have the tap fully turned on.
At the kitchen sink where in our case we have a domestic kitchen tap (bought in B&Q) fitted there is adequate pressure but not the kind of pressure which results in water splashing everywhere.

I suppose the big question for me would be..................... would you fit the same size of pipe in your next conversion, my answer would be "absolutely"!
The only problem you might have is getting the fitments which will take the 10mm up to the sizes of your taps etc., but this wasn't a problem for me as I simply went along to the professional trade plumbing suppliers Plumb Centre who will no doubt have an outlet just down the road from you.

ATB

Phil

 

[Vicdicdoc]

Thanks Phil, that’s reassuring to know & I’m convinced !
Vic

 

[Misterg]

The solid red and blue 12mm plastic pipe widely sold for caravan / campervan water seems to be the same stuff (nylon?) as industrial air hose.

Actually, I've found out that it isn't. The proper John Guest stuff is LLDPE (a type of polythene) which is food safe, etc.

Sorry if anyone was misled

 

[Vicdicdoc]

Ok, I think I've got all the JG fittings & 10mm piping (+ pipe inserts), I read that the pipe should be cut using one of the JG pipe cutters (being a cheapo can I just use a hacksaw ?

 

[Deleted member 4404]

If you use a hacksaw you will need to de-burr every cut. A pair of pipe shears will give you a clean 90 degree cut every time and you can use them on soft plastic tubing as well. This type of cutter from screwfix is £12 well spent --- PIPE SHEARS

 

[wildebus]

I have a pair of cable cutters very similar to these - https://amzn.to/2HjS7nV
Very multi-purpose.... used them on the 12mm plastic pipe, 2mm heater fuel pipe and yesterday was using them to cut 70mm copper cable.

 

[Squiffy]

Ok, I think I've got all the JG fittings & 10mm piping (+ pipe inserts), I read that the pipe should be cut using one of the JG pipe cutters (being a cheapo can I just use a hacksaw ?

I always use a sharp knife or razor though I have used a hacksaw in the past, just make sure the cut is square and the cut has no ragged burrs, i.e. make sure the cut is clean edged. I've never used inserts? Didn't know they were necessary on semi rigid 12/10mm polypropylene polypipe, I'm aware they are on 25mm blue but the fittings on that are different. Phil.

P.s. Never had any problems in 15 years not using inserts.

 

[Deleted member 4404]

The inserts prevent ovality and give a tapered leading edge, so reduce the risk of damaging the seal.

 

[Squiffy]

Yes Chris I'm well aware of the use of inserts, I built the whole pontoon water system for Cardiff bay Yatch club when I worked there all in 25mm poly and of course had to use inserts ( missed in a few joints as I ran out on occasions, but to my knowledge have never given way ). But 25mm is a different kettle of fish in comparison to 12/10mm pipe the wall thickness of 12/10mm in percentage terms is makes them far more ridgid and unlikely to deform even under hot water conditions, indeed as I stated in my last in 15 years apart from on one occasion where I had not pushed the pipe into the joint far enough, I have never had a problem, just seems unnecessary to have inserts in my view anyway. Phil

 

[Millie Master]

I always use a sharp knife or razor though I have used a hacksaw in the past, just make sure the cut is square and the cut has no ragged burrs, i.e. make sure the cut is clean edged. I've never used inserts? Didn't know they were necessary on semi rigid 12/10mm polypropylene polypipe, I'm aware they are on 25mm blue but the fittings on that are different. Phil.

P.s. Never had any problems in 15 years not using inserts.

I was of that opinion Phil up until l built the shower block at La Tournerie where I used alkathene pipes to bring the water down from the water/solar panels on the roof down to the hot water cylinder. The summer of 2008 was a very hot one in the Dordogne, so hot in fact that the water temperature in the tank was approaching boiling point (yes that hot). I was across the road from the site when one of our friends came running over to tell me that the entire shower block was flooded out and that there was no electricity!
The reason was that one of the alkathene pipes that I hadn't used inserts in had blown off from a coupling allowing mains water at very high pressure to squirt all over the bloody consumer units!!!

Lesson learnt, from that day on I have always used inserts if they are available.

Phil

 

[Deleted member 4404]

I had a joint give way on the hot water circuit in a narrow boat and it was the only one I had forgotten to fit an insert in. That was in 15mm and the pipe was on a curved run, so I presume the heat had let the pipe go out of shape. Since then I have always used them!

 

[Squiffy]

I was of that opinion Phil up until l built the shower block at La Tournerie where I used alkathene pipes to bring the water down from the water/solar panels on the roof down to the hot water cylinder. The summer of 2008 was a very hot one in the Dordogne, so hot in fact that the water temperature in the tank was approaching boiling point (yes that hot). I was across the road from the site when one of our friends came running over to tell me that the entire shower block was flooded out and that there was no electricity!
The reason was that one of the alkathene pipes that I hadn't used inserts in had blown off from a coupling allowing mains water at very high pressure to squirt all over the bloody consumer units!!!

Lesson learnt, from that day on I have always used inserts if they are available.

Phil

 

[Squiffy]

Yes I do agree with 25mm pipe work Phil especially on the hot water side of things ( In Cardiff Bay of course it was all cold water ) and so I got away with it. I'm not saying don't use them on 10/12mm I just personally think in the terms if caravan and motorhome its not absolutely necessary, indeed in caravans that i2have worked on I've never found inserts being used? Phil

 

[Millie Master]

indeed in caravans that I have worked on I've never found inserts being used? Phil

I agree with you Phil about inserts not being used in caravans etc., but I have found that every single one of the very many caravans I have serviced over the years that so many of them had leaks at taps, showers or other such joints. Possibly if the manufacturers of these mega expensive caravans weren't so damned penny pinching they might actually use good quality materials?
Phil

 

[Vicdicdoc]

For the minuscule extra cost I've got inserts - and pipe shears (from Screwfix - half the price of branded JG ones)

 

[Vicdicdoc]

Another question- should I get & insert these collets in the joints

 

[Squiffy]

Another question- should I get & insert these collets in the joints
View attachment 919

If they are pennies then why not, never used them myself infact I have found in the past that if the pipe is inserted properly it can sometimes be a real pain trying to pull the pipe out even with the coller fully depressed. Phil