Plumbing experiment.

Billjratt

Billjratt

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I decided to use blue (underground) water hose for part of the calorifier plumbing. Joining it to the real world involves heating and forcing a copper fitting inside.
I am considering involving sealant/glue/putty as well.
Any seasoned plumbers out there done it sucessfully?
 
Bill - the pipe is MDPE ( medium density polyethylene) and you need a

"Universal Transition Fitting" of the right size to connect to copper.

Try BES for example, online.

Good luck
 
Bill,

Been playing around with plastic pipework for a no of years now, & the best product for your application would be a CPVC pipework system, which can do both hot & cold water.
There are many manufactures out there but you would be better of going to your local Plumbcenter or Wolsey & see what they stock they will also give you some advice.. you can go to durapipe & get an idea of the product also some info on jointing techniques.
Personally, I would always use a copper male/female iron to connect onto the calorifier. then a transition adaptor to your CPVC.
Good luck

poter
 
The blue pipe is really designed for cold mains water. A better alternative would be Hep pipe and fittings. If you do use the blue MDPE pipe, be SURE to put in inserts into the blue pipe first. The same applies to Hep pipe and fittings - you must use an insert. The inserts are plastic and easy to insert. To join the blue pipe to copper, you need a 'Plasson' fitting. Any wholesaler (incl. screwfix) sell inserts, plasson fittings and Hep pipe and fittings. Finally, the key to plastic pipework and fittings is to make sure that you FULLY insert yhe pipework into the fittings.
 
Do it properly using Hep or polypipe, all the fittings are available, unless its QE2 its not going to cost a fortune.

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sealant/glue/putty

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Well, the lid is truly off the jar of worms now!
Thanks for all that info guys, I'll go and investigate it all. The main reason for using blue pipe is that a longish run with no joints apart from the ends would be acheivable.
 
Just to add to what has already been said:

As far as I recall, the pressure rating of MDPE is significantly reduced at higher temps, it's used mainly for potable cold water supply in Construction.

Whilst no doubt you could get away with it at the pressure/temp you are likely to encounter (careful though pressure can build if over-temp controls, or expansion vessel fail) why take the risk?

What with the cost/problems getting hold of MDPE adaptors/fittings should a leak occur - I would recommend Hep2o as others have said!
 
Hi Bill,

As well as a long term boat owner I also work for the parent company of Durapipe.

Just to clear one thing up. DO NOT USE MDPE OR HDPE PIPE FOR HOT WATER. IT WILL FAIL!

As far as other solutions for hot water services are concerned you can use a number of the proprietary push fit systems such as Marley Equator, John Guest etc... as already stated. I suggest using a PEX or mutilayer pipe with these fittings.

You can use blue HDPE for Domestic Cold Water yet it isn't a great product to install aboveground, particularly onboard. Jointing systems such as Philmac offer a complete range of fittings and adaptors onto other fittings for HDPE. Note that you cannot solvent weld (glue) MDPE.

CPVC is another solution for hot and cold water services and is available under the Friatherm brand from BSS or Wolseley. This is a solvent welded system. This offers a permanent joint that cannot be dismantled.

Speak to the Durapipe Technical Support Team if you need more help. Hope this helps.
 
Definitely vote for hep20 or similar.
Another point to look into is the possibility of changing some runs down to 10mm pipe, on my boat this meant the long run to the heads could be one piece due to the tighter bend radius possible. Also this meant that much less hot water was wasted waiting for the shower to run hot. The flow rate was OK, particularly as we wanted to be sparing with water anyway, due to small calorifier+ tanks. You can easily plug together a temporary run of pipe to see what the flow rate will be.
Some of the 20year old connections were showing sign of minor leaks, possibly due to vibration, stress or poor installation, as the pipework in the bilge was not secured well.
I would avoid joins as much as possible, all sizes of poly pipe are available in long coils, but sometimes straight 2m lengths are easier to get a neat straight pipe.
 
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