Errrmmm... quickie workshop plumbing question

[ondablade]

Borderline for a woodwork forum I know, but I'm plumbing in radiators in the workshop, and having a bit of difficulty making tight bends of about 4in rad in 1/2in copper to connect the valves to the flow and return pipes.

Having run into problems with wrinkling of the inside of the bend (using a spring on heat annealed tube - my knee is sore too) i'm about to capitulate and use 2 x compression elbows. Proper benders seem quite expensive.

The last chance hotel might be to anneal a second time and go again, but i'm not sure if it'll help.

Before i do does anybody have any smart ways to get a tight bend with a spring?

Thanks

 

[jasonB]

You could probably hire a bender for a day. Or make a wooden bending block to save your knee when using the spring

Jason

 

[paulm]

Any reason for not using elbow solder joints, cheaper and less leak prone than compressions ?

Cheers, Paul

 

[petermillard]

Cheap pipe bender from plumbworld:-

http://www.plumbworld.co.uk/heavy-duty- ... =205025294

Or use elbows. Or push-fit - seriously; I learned to solder copper a long time ago and resisted push-fit for a long time, but I did a bathroom last year and the plumber I sub all the wet work to on bigger projects has moved to push-fit & plastic pipe in the last 12 months and honestly, it's absolutely fantastic. I don't show it on the surface for aesthetic reasons, but out of sight it's fabulous.

Pete

 

[knappers]

Pete's right - I used to solder everything, and was also doubtful about push fit. The plumbers that were contacted by my builder for the house extension used plastic for all hidden work and swear by it (not at it).

Si.

 

[wobblycogs]

We've just coming to the end of installing all the heating and plumbing in out place and it's all done in plastic push fit. There are probably upwards of 300 joints in the house and to date we haven't had a single bad one. We use the JG Speedfit pipe and connectors as recommended by out plumbers, they aren't the cheapest but they are good. You can also push them straight onto copper pipe which is very convenient.

The only word of warning I would say is you must use inserts on plastic pipe (as detailed in the instructions). The plastic pipe softens when it gets hot and if you don't put an insert in it can slowly develop a leak.

 

[ondablade]

Thanks Paul, i'd not thought of solder connections - brain fade, as i'd made quite a lot of use of them when relocating a hot water cylinder to make room for my cyclone.

Hiring a bender is a runner too Jason, more brain fade! Think on balance though i'll be lazy and go with the solder as i have the fittings in stock and it's a fair run to a decent hire shop.

More generally I've been struggling with the idea of QualPex and push fittings too, in that i keep on thinking of the plastic creeping, and tolerance and movement problems on the push fittings. But you're (all) right - a plumber i highly respect did a bathroom for us recently, and used them throughout. Says he's had no issues over many years. I meanwhile found some sneaked in under a floor in by his predecessor about 10 years ago while stripping out old piping in the loft over my workshop on the cyclone job - no hassles there either.

Another nice move the bathroom guy went for which might be of interest - he ran the QualPex through conduit, and brought all the connections back from the bath, shower and basin to two manifolds under the bath. So no joints under the concrete sub floor, all joints accessible, and even the piping runs can be replaced if needed.

Thanks again...

 

[matt]

I've never heated the copper before bending it. Might that be the cause of the problem - the copper is too soft?

Just a thought.

 

[jasonB]

The only thing I don't like about plastic pipe & push fit is that the inserts are only about 8mm bore for 15mm pipe and on a gravity system this must restrict the flow.

Jason

 

[jams]

I would use speed fit in an external building as the pipes are less likely to split with a good frost, also, you wouldn't run into the same problems as your having. As been said, you can use copper on speed fit too

 

[wobblycogs]

We wondered about flow restriction caused by as well the inserts so we asked about and did some reading and it would seem that it isn't that much of a problem. The inside of the plastic pipe is much smoother than the inside of copper and you can often run much longer single lengths of plastic so over all the flow rates turn out to be about the same.

Having said that we've installed a mains pressure system so a slight drop in pressure wasn't so much of a concern.

 

[Eric The Viking]

Couple of things:

1. Be very careful if you hire a bender: test it on the counter before you leave the hire shop. They wear, and when they do they wrinkle the pipe instantly - it has to be a very tight fit in order to work. I used to hire but bought mine because of this. The wear to the formers is almost invisible to the naked eye, and the wrinkling is harder to avoid in modern thin-wall piping. Furthermore, proper 1/2" pipe benders probably haven't been available in the UK for three decades -- I've never seen one. I'm not saying they're not available in Eire (I don't know), but watch out you don't get offered 15mm instead!

2. Wrinkled pipe on the inside of the bend won't matter in the slightest for radiators, as the flow rate is so slow. It _does_ matter for mains pressure cold water - I always put slow bends (large radius) in kitchen tap pipes (and toilet cisterns feeds, if I can), to keep them quiet.

3. You can quite happily plumb radiators in 10mm, or even 8mm if the rads are small, and couple that to ordinary piping. Flow rates don't need 15mm, and it's far easier to put in awkward spaces. Even if there's ordinary 15mm in proximity, when I replace a radiator I usually do 3ft 'tails' in 10mm, as it looks neater and reduces the pump noise emanating from the radiators significantly. Some old plumbers will tell you you can't mix 'microbore' and ordinary piping: this is complete nonsense.

4. If it's your workshop the pipes are most probably visible, but if you're burying them in/through walls, insulate them first, electrically, I mean. I use heatshrink over the pipe usually. It stops a lot of the corrosion that otherwise occurs (see other threads). If you have to tidy a hole, expanding foam is good (you can fill it and paint it, etc.), and it's a good insulator both electrically and thermally. Note: they don't corrode in the winter, when the rads are on, but in the summer, when they're cold and any damp in the wall gets to them. Those little 'U' shaped things for radiator brackets are a good idea too: they reduce expansion noises a lot, and they insulate the radiator from the wall.

5. I'm dead nervous of plastic. One major housing association I know uses it but forbids any inaccessible couplers, and when I did use it, about ten years ago, I had older fittings degrade, in a dark cupboard! Yes it's easier and cheaper, but IMHO it's not been in use for anywhere near long enough to assess the long term stability.

HTH,

E.

 

[RogerS]

..... Yes it's easier and cheaper, but IMHO it's not been in use for anywhere near long enough to assess the long term stability.

HTH,

E.

20 years long enough? That's the age of our Hep2O system...no leaks. Personally I prefer Hep2o as I find the Speedfit ones a bit to large and clunky.

One point worth noting....do not use plastic connectors on chrome pipe. The gripper teeth just slip off.

 

[Eric The Viking]

..... Yes it's easier and cheaper, but IMHO it's not been in use for anywhere near long enough to assess the long term stability.

HTH,

E.

20 years long enough?

Nope.

I was permanently scared off by the fitting I had that discoloured and started to depolymerize. It took about four years. :shock:

I have one nominally 22mm piece left in the house: a loop about 3ft round that bridges from the stop tap to the mains cold riser, put in as a temporary measure. You've reminded me: I ought to get rid of it ASAP.

Perhaps I should be Eric-the-Luddite? :wink:

 

[tsb]

Rats love the plastic pipe. I've seen a few fittings and pipe gnawed through over the last few years. Personally I would stick to copper and solder joints even though plastic is so much easier to use.

 

[markymark12]

Copper for me to.

i know of a case of a claim against Speedfit where on a extension 6 months on from completion whilst the couple were away a fitting failed. Upon their return, the house was flooded minus a ceiling. the result after the contractor getting the speedfit manufactures in, was a charge against speedfit, which they then paid out for the repairs after examining the fitting in question.

To my mind who wants to rip out their pipework work after 20years and replace it?

I cannot say i have ever been keen of microbore myself. i have pulled of rads and pipework after it has been installed for a lengthy period of time it must be said, to look down the end of the pipe to see a furred up old pipe with a tiny pathway for the water to flow though. Glad to say it has died a death after finding favor many years ago, i cannot remember the last time i saw any installed. This is where people shout power flush, no maintenance, and yes very important issues but truth is, people do not bother a lot of the time until it all goes wrong, by which time what do you tell them.

Plastic is great for earning lots of money on first fixes mind, now would that have anything to do with guys liking it :roll: :roll: no i am sure it does not appeal to lots for that reason. i will stick to copper myself.

 

[Eric The Viking]

Copper for me to.
. . .
I cannot say i have ever been keen of microbore myself. i have pulled of rads and pipework after it has been installed for a lengthy period of time it must be said, to look down the end of the pipe to see a furred up old pipe with a tiny pathway for the water to flow though. Glad to say it has died a death after finding favor many years ago, i cannot remember the last time i saw any installed. This is where people shout power flush, no maintenance, and yes very important issues but truth is, people do not bother a lot of the time until it all goes wrong, by which time what do you tell them.

Plastic is great for earning lots of money on first fixes mind, now would that have anything to do with guys liking it :roll: :roll: no i am sure it does not appeal to lots for that reason. i will stick to copper myself.

First fix? Probably so, although, as I mentioned at least one big housing association is getting quite wary of it.

Regarding microbore, for mains pressure feeds it's the norm in the USA :norm: (no, not him!).

If the system is properly maintained it shouldn't cause problems, but I can understand why it might. Our system always runs clear when drained at the lowest point, it's got over-strength inhibitor, and I aim to keep it that way!

Cheers,

E.

 

[ondablade]

Thanks for the info Eric. Two bits of info in return:

1. Creep (plastic flow) and the effects of UV bother me a bit too so far as plastics are concerned. Notwithstanding that QualPex seems to be developing a decent track record the fact is that there really isn't any way to simulate real world aging.

I watched 'accelerated aging' tests done on adhesives (also polymers) for long enough when working in that industry, but i could never extract a credible explanation from the chemists as to exactly how confident they were that elevated temperatures and reduced cycle times actually did mimic reality. The fact is anyway that it's usually the unforeseen variable that trips these things up.

2. Apart from noise it makes sense to keep the velocity down in copper pipes - the likes of Myson offer balancing/by pass valves for this purpose - and it's best to match pumps to boiler and piping sizes. My metallurgy lecturer taught us that there is a critical flow velocity it's best not to exceed for water in copper pipes - once you get past it it scours away the oxide layer that prevents corrosion as fast as it can form. Theres a classic form of horseshoe/crescent shaped pit that typically develops it seems - where a spot of debris on the surface caused an increase in water velocity as it flows around it.

PS the rads are now in....

 

[sparkymarky]

making tight bends with a bending springs is almost pointless they are not designed for that. to bend sucessfully the radius of the bend must be split into three sections normally of about 2 1/2" which is then bent in the 3 sections one after another, checking constantly that the spring isn`t stuck in the copper, dont bother heating it for 15mm either.
ideally get a hilmor copper bender, however i have a rothenberger bender which is just fine.
advise from a professional plumber of many years AVOID "pushfit" fittings like the plauge, if you are using them the system must be pressurised to 10 bar to ensure the fitting grips the tube properly, many people dont and the fittings tend to blow off or leak after a few years (john guest recomend this).
a properly soldered copper fitting can last for over 50 years. a pushfit fitting has a guarantee of 25 years i wouldn`t fancy a house full of pushfit fittings burried in my walls and ceilings.
hope this helps, any questions pm me.
mark.

 

[RogerS]

...
advise from a professional plumber of many years AVOID "pushfit" fittings like the plauge, if you are using them the system must be pressurised to 10 bar to ensure the fitting grips the tube properly, many people dont and the fittings tend to blow off or leak after a few years (john guest recomend this)......
mark.

I'm sorry but that just sounds like pure bul*s*it and prejudice. If that was the case the internet would be full of such dire warnings. It isn't.