Barney12 Posted July 31, 2017 Share Posted July 31, 2017 (edited) Hi, almost certainly a question for our resident eggspurt @Nickfromwales The picture below shows the connector to join the 32mm ground pipe to the 22mm internal pipwork. The brass is (I think) just one of those bog standard 1" tank connectors. But the male union thread on the other fitting is plastic. Whats the best method to join these? I'm concerned that too much PTFE tape/chord could cause the plastic thread to strip or crack. This joint is going to be buried in the wall so I need to be sure of a permanent connection. Ta muchly in advance. Edited July 31, 2017 by Nickfromwales Brass not copper :-) Link to comment Share on other sites More sharing options...
Nickfromwales Posted July 31, 2017 Share Posted July 31, 2017 A bit risky if it's going to be buried. If it's not too late, can you get one of these instead ? Link to comment Share on other sites More sharing options...
Jeremy Harris Posted July 31, 2017 Share Posted July 31, 2017 I'm with Nick on this, as I have a couple of MDPE to 22mm connections. I used these: https://www.pipestock.com/philmac/adaptor-kits/copper-connection-kit as they just fit into an MDPE coupler or elbow and convert it to take a copper pipe on one side. Link to comment Share on other sites More sharing options...
Barney12 Posted July 31, 2017 Author Share Posted July 31, 2017 30 minutes ago, Nickfromwales said: A bit risky if it's going to be buried. If it's not too late, can you get one of these instead ? No not too late. Its a job I need to do next weekend. (Get me with my planning ahead abilities ) That does look better. Link to comment Share on other sites More sharing options...
Barney12 Posted July 31, 2017 Author Share Posted July 31, 2017 12 minutes ago, JSHarris said: I'm with Nick on this, as I have a couple of MDPE to 22mm connections. I used these: https://www.pipestock.com/philmac/adaptor-kits/copper-connection-kit as they just fit into an MDPE coupler or elbow and convert it to take a copper pipe on one side. So that piece fits inside a coupler? Doesn't look as though they do 32mm to 22mm though and I don't want to introduce another joint if I can help it. (Although I could run in 28mm until I get to the install position and reduce their as that's accessible). Link to comment Share on other sites More sharing options...
Barney12 Posted July 31, 2017 Author Share Posted July 31, 2017 50 minutes ago, Nickfromwales said: A bit risky if it's going to be buried. If it's not too late, can you get one of these instead ? Oh bother. Just noticed that it says "copper". I'm connecting to 22mm Hep2o. Do you think its still OK? Link to comment Share on other sites More sharing options...
Jeremy Harris Posted July 31, 2017 Share Posted July 31, 2017 10 minutes ago, Barney12 said: So that piece fits inside a coupler? Doesn't look as though they do 32mm to 22mm though and I don't want to introduce another joint if I can help it. (Although I could run in 28mm until I get to the install position and reduce their as that's accessible). Yes, it fits inside a coupler. I used 25mm MDPE, as that's about the same bore as 22mm copper, but you could just fit a short length of 28mm copper with a 28mm to 22mm reducer soldered on to get you to 22mm. I've found these fittings very secure, as the stainless steel grip ring bites hard into the copper pipe, holding it very securely in place. Link to comment Share on other sites More sharing options...
Nickfromwales Posted July 31, 2017 Share Posted July 31, 2017 7 minutes ago, Barney12 said: Oh bother. Just noticed that it says "copper". I'm connecting to 22mm Hep2o. Do you think its still OK? Best to run copper until your out of the buried part, and then use a Hep socket or bend to convert back. Link to comment Share on other sites More sharing options...
Barney12 Posted July 31, 2017 Author Share Posted July 31, 2017 11 minutes ago, Nickfromwales said: Best to run copper until your out of the buried part, and then use a Hep socket or bend to convert back. Oh bother. I ran the 22mm Hep last week Link to comment Share on other sites More sharing options...
Nickfromwales Posted July 31, 2017 Share Posted July 31, 2017 Just convert at the mdpe fitting then. They're bullet and bombproof so I wouldn't bat an eyelid burying one of those. Maybe ring Hepworth tech and ask them if it'll go straight in with a stainless insert ? Link to comment Share on other sites More sharing options...
ProDave Posted July 31, 2017 Share Posted July 31, 2017 I will be the stick in the mud here. I have used the type of mdpe to copper converter that has been recommended. I did not like them and would not want one buried in an inaccessible location. My "issue" is that it's just a rubber bung that gets compressed onto the copper. Even when tightened the copper can still flex / move a bit. Although it never leaked, it did not inspire confidence. I would much prefer the fitting Barney proposed, at least the copper connects with a proper olive in a brass fitting. I would not worry about damaging the plastic thread, you really would have to overdo the amount of ptfe for that. Actually my preferred solution is a brass sropcock that takes 25mm mdpe at the input and 22mm copper at the output. Those are really bomb proof. 2 Link to comment Share on other sites More sharing options...
Jeremy Harris Posted July 31, 2017 Share Posted July 31, 2017 19 minutes ago, ProDave said: I will be the stick in the mud here. I have used the type of mdpe to copper converter that has been recommended. I did not like them and would not want one buried in an inaccessible location. My "issue" is that it's just a rubber bung that gets compressed onto the copper. Even when tightened the copper can still flex / move a bit. Although it never leaked, it did not inspire confidence. I would much prefer the fitting Barney proposed, at least the copper connects with a proper olive in a brass fitting. I would not worry about damaging the plastic thread, you really would have to overdo the amount of ptfe for that. Actually my preferred solution is a brass sropcock that takes 25mm mdpe at the input and 22mm copper at the output. Those are really bomb proof. The ones I used (as in the link earlier) had a stainless steel ring to "bite" into the copper, a lip seal that fits around the copper pipe and is compressed to form a seal and a rigid plastic ring that fits under the MDPE fitting compression nut to hold the whole thing together. There's no flex or movement at all, the whole things is very rigid when tightened up, as the rigid plastic ring engages in the bore of the MDPE fitting to keep thing in line.. Link to comment Share on other sites More sharing options...
ProDave Posted July 31, 2017 Share Posted July 31, 2017 Just now, JSHarris said: The ones I used (as in the link earlier) had a stainless steel ring to "bite" into the copper, a lip seal that fits around the copper pipe and is compressed to form a seal and a rigid plastic ring that fits under the MDPE fitting compression nut to hold the whole thing together. There's no flex or movement at all, the whole things is very rigid when tightened up, as the rigid plastic ring engages in the bore of the MDPE fitting to keep thing in line.. That sounds a lot better that the fitting I had. I would put this in the category of a fitting you want to buy from a shop, where you can see it before you buy it, and NOT something to buy mail order, because I can assure you some variations on this fitting are rubbish. Link to comment Share on other sites More sharing options...
Nickfromwales Posted August 2, 2017 Share Posted August 2, 2017 Bingo 1 Link to comment Share on other sites More sharing options...
Nickfromwales Posted August 2, 2017 Share Posted August 2, 2017 On 31 July 2017 at 11:55, ProDave said: Actually my preferred solution is a brass sropcock that takes 25mm mdpe at the input and 22mm copper at the output. Those are really bomb proof. Nope, I will be the stick I greatly dislike putting any metal compression fitting onto plastic ( mdpe ) as I just can't see how a metal olive being compressed onto plastic is ever a good idea. I've done loads when fitting kit supplied by others, but still avoid it on my own jobs. I will also kick in the testicles, anyone who works for me that puts speedfit pipe into a compression fitting. SQUARE in the testicles, and not a glancing blow, btw. ? Link to comment Share on other sites More sharing options...
Barney12 Posted August 2, 2017 Author Share Posted August 2, 2017 3 hours ago, Nickfromwales said: Bingo Now that looks like the baby! Link to comment Share on other sites More sharing options...
Barney12 Posted August 4, 2017 Author Share Posted August 4, 2017 On 02/08/2017 at 09:08, Nickfromwales said: Bingo Ta Da! Thanks Nick. Dry pressure in test in progress. A wet test is going to need some thought as I need to get close to 80ltrs of water and antifreeze into the pipes with no mains water connection available yet! I'll have to see if I can rig up a very long hose from the garage. 1 Link to comment Share on other sites More sharing options...
Jeremy Harris Posted August 4, 2017 Share Posted August 4, 2017 I filled and pressurised our UFH with no water supply, using a cheap pressure sprayer, modified with a fill loop hose and valve. This allowed antifreeze to be pumped in, under pressure, although I had to fill the modified sprayer up a few times. These things will pump up to around 3 or 4 bar, I think, although I only pumped ours up to 1.5 bar. Link to comment Share on other sites More sharing options...
Barney12 Posted August 5, 2017 Author Share Posted August 5, 2017 (edited) Well the dry test had lost 1 bar of pressure over night Not sure though if the cheapo dry test thingy from Toolstation is that great? The 15mm push fit connector doesn't exactly feel robust. I best get some H2O into it and test it properly. @JSHarris What did you connect to the pressure sprayer to fill the pipes? Edited August 5, 2017 by Barney12 Link to comment Share on other sites More sharing options...
Jeremy Harris Posted August 5, 2017 Share Posted August 5, 2017 16 minutes ago, Barney12 said: Well the dry test had lost 1 bar of pressure over night Not sure though if the cheapo dry test thingy from Toolstation is that great? The 15mm push fit connector doesn't exactly feel robust. I best get some H2O into it and test it properly. @JSHarris What did you connect to the pressure sprayer to fill the pipes? The pressure will change a lot with temperature when using air, so you may not have a problem. To make the pressure tester, I replaced the outlet hose from the pressure sprayer with a longer length of 8mm HDPE pipe, which sealed tightly to the 8mm pipe fitting on the sprayer, and on the other end I used an 8mm to 15mm adapter, that fitted to the filling loop pipe. It's currently on loan to @jack, who may be able to take a photo of it (I forgot to take any when I made it). Link to comment Share on other sites More sharing options...
jack Posted August 8, 2017 Share Posted August 8, 2017 Sorry, I was away over the weekend and forgot to reply to this when I got back. I'll take some photos tomorrow. Link to comment Share on other sites More sharing options...
jack Posted August 10, 2017 Share Posted August 10, 2017 Here we go @Barney12 and @JSHarris: Link to comment Share on other sites More sharing options...
Russell griffiths Posted August 10, 2017 Share Posted August 10, 2017 Your a clever sod mr @JSHarris? Link to comment Share on other sites More sharing options...
Barney12 Posted August 10, 2017 Author Share Posted August 10, 2017 1 minute ago, Russell griffiths said: Your a clever sod mr @JSHarris? +1 Link to comment Share on other sites More sharing options...
Jeremy Harris Posted August 10, 2017 Share Posted August 10, 2017 Not really, it took me two goes to get it to work! It was mostly good luck, discovering that the cheap pump spray used an 8mm hose, with a compression fitting where it attaches to the pressure bottle. I happened to have a length of 8mm LDPE pipe, and that fitted directly into the pressure bottle fitting. This 8mm LDPE pipe takes standard 8mm compression pipe fittings , as long as a brass insert is used. The rest was easy, just an 8mm to 15mm compression adapter, an standard 15mm NRV, and then a standard fill loop hose. To use it, you just fill the bottle with antifreeze/inhibitor, screw the filling loop hose on to the fill point valve, open the valve and start pumping. It very easily pumps our ASHP/UFH loop up to 1.5 bar, the only chore is stopping to refill the bottle every few minutes. In our case it's not a big problem, as it's only around 4 or 5 refills to get the system full initially. When I drained and refilled the system after working on it it was only a single bottle full, as the UFH loops remained filled, as I only drained as far down as the lower manifold. Link to comment Share on other sites More sharing options...
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