Squeezing copper tube?

[noel shelleyParticipant @noelshelley55608]

The REAL problem with 70s copper was the price and the wall thickness due to price ! It was thin wall and was so thin it could NOT be bent. If you know what a squeeze off is then 2 bits of round bar and some work will make you a copy to crimp your pipe. IF the pipe is table 1 then it will be ok if thin wall your on your own.

I have a system that uses gravity HW and pumped CH, the 2 come together at a T. The pumped side comes in on the branch and stops the gravity flow. It should have been brought in on an injector T ! Noel.

[HopperParticipant @hopper]

Posted by John Doe 2 on 01/02/2023 10:44:51:

Thanks again tor the (sensible) replies.

I will say once more that this is a temporary fix only and I will of course be making a proper fix in due course. The reason I don't want to drain the system at the moment is because it is winter and I don't know what I might find or what horrors might reveal themselves – e.g. dislodging debris built up in partially blocked pipes, like in the photos above.

A potentially simple quick fitting of an extra valve could easily morph into a major production, which I am very keen to avoid just at the moment !

I did not install this system so I don't know how badly, (or if), it was cleaned out and commissioned, and I could potentially put the system completely out of action, whereas it does sort of work at the moment. There is other more pressing work required on the house so I just need a temporary fix. The potential of copper tube cracking is why I am asking you; the experts! The squeeze would not be to pinch the pipe off completely, just restrict it partially.

I also don't want to waste a load of inhibitor by draining down only to have to buy another system's worth of expensive inhibitor in a month's time.

PS, in answer to another question; yes,I have tried different pump speeds, as well as adjusting the balance of all the radiators

Edited By John Doe 2 on 01/02/2023 10:53:55

It's not something any expert can tell you with any certainty. It might split, or it might not, depending on many factors including grade of tube, age of tube, condition of tube, how it is squeezed, level of gunk inside the tube and so on. As you have said yourself, messing with old plumbing can be the genesis of many horrors. All you can do is either drain the system and do it properly, or try the squeezing method and be prepared to quickly drain the system if it splits, either immediately or later on at some unknown point when the weakened metal gives way.

Your choice. Personally, I would not risk it, based on having worked for some years maintaining rotten old pipework in industry and hospitals. See Murphy's Law posted above.

The other question is: Will squeezing a copper tube reduce the flow? As you squeeze the tube top to bottom, it deforms and bulges out sideways, maintaining the same cross sectional area and thus not restricting flow. Until you get to a certain point where it has reached near full width and you start to close down the elongated slot shape left. At this point the copper at the ends is being forced into a sharp bend, much more likely to split.

Edited By Hopper on 01/02/2023 11:20:02

[Ian PParticipant @ianp]

A few replies ago, Kiwi Bloke asked….

Not sure how your controller is arranged. If you have two circuits, each valve-controlled, what happens if both are 'off' at the same time?

From The OP's description the existing installation sounds to be plumbed reasonably sensibly but is lacking in the control method.

Rather than squeezing pipe why not solve the problem electrically?

I may be wrong but I do not recall seeing restrictors being required in installations fitted with electrically operated valves.

Ian P

[Martin KyteParticipant @martinkyte99762]

I would expect aluminium use in overhead power transmission to be down to weight. You need more cross section for the same conductivity as copper but you end up with half the weight. The load on the Pylons, hanging insulators, and steel reinforcing is reduced which saves cost let alone the cheapness of Al compared to copper.

Regards Martin

[Sam Longley 1Participant @samlongley1]

Turn it off. Let it go cold. Buy a freeze pack, or hire one. Freeze the pipe . Cut it & insert a ball valve. You can then play with the amount of restriction as much as you like.

Copper would come as table X Y Z the thickest being for underground use. The thinnest- thinwall-, could not be bent in plumbers bending machine. If your house does not have loads of bent sections of copper, but bends made with fittings, then it is more likely, thinwall & you will crack it for sure.

[Dave HalfordParticipant @davehalford22513]

If I turn off all the rads both ends in my 4 bed house I get less than two buckets of water out. I just pour it back in via the feed tank.

[duncan webster 1Participant @duncanwebster1]

Posted by Hopper on 01/02/2023 11:13:28:

………

The other question is: Will squeezing a copper tube reduce the flow? As you squeeze the tube top to bottom, it deforms and bulges out sideways, maintaining the same cross sectional area and thus not restricting flow. Until you get to a certain point where it has reached near full width and you start to close down the elongated slot shape left. At this point the copper at the ends is being forced into a sharp bend, much more likely to split.

Edited By Hopper on 01/02/2023 11:20:02

Of course it will, it's the perimeter that remains the same, not the area. In the limit if you squash it flat it will have no area. I was once sent to deal with a stuck whistle valve on a steam loco. Tapping the valve and wiggling the stem didn't sort it, but hammering the pipe flat at least meant the driver could hear himself think whilst he got the train back to base for a proper cure

[OldironParticipant @oldiron]

Posted by Sam Longley 1 on 01/02/2023 12:22:43:

Turn it off. Let it go cold. Buy a freeze pack, or hire one. Freeze the pipe . Cut it & insert a ball valve. You can then play with the amount of restriction as much as you like.

Copper would come as table X Y Z the thickest being for underground use. The thinnest- thinwall-, could not be bent in plumbers bending machine. If your house does not have loads of bent sections of copper, but bends made with fittings, then it is more likely, thinwall & you will crack it for sure.

That is definitely the easiest method to use. I have just replaced and moved a 2 metre long radiator in my study.

I bought the radiator and freezer packs from Toolstation. I had read some horror stories about using freezer packs so read and reread as much info as I could find. The most important things I learned were:-

1. Make sure that the instructions are followed to the letter.

2. Have all the parts to hand, prebend or make as many joints off the job ready to be fitted.

3. Preperation is the key, remove any paint from the pipes where you need to freeze them. The paint has an insulation effect and will slow the freezing down. Clean the pipe where you are going to add a fitting before freezing & cutting.

The pipe freeze lasted for about 15 minutes in my case. REMEMBER moving water does not freeze so make sure everything is off.

regards

[Stuart Smith 5Participant @stuartsmith5]

Another vote for using a pipe freezing kit to fit a valve.

I fitted an extra radiator recently and didn’t fancy draining the system in winter.

It worked well.

Just make sure you get a kit made for the bigger pipe and if possible fit it near a bend so that you can move the pipe to get room to install the valve. You only need to do one cut of the pipe then.

You would probably want to do this anyway when you install the extra controls.

Stuart

[John Doe 2Participant @johndoe2]

Well, I am not going to risk squeezing the tube, and as I say, I don't have the time to fit a valve right now, nor do I want to disturb the system until winter is over. Doing so will cause a lot of woe – I have no doubt of that ! – so I am letting sleeping dogs lie.

My temporary solution is to have only the heating coming on with the timer, and the HW set to off. Then in the middle of the day when I am up, I will override the HW to on for an hour to heat the HW tank, then force it off again. That will give us sufficient hot water for a shower each, the next morning.

That way, we will have the heating automatically in the morning, without the HW coil stealing all the heat, and I won't have to get up early in a cold house to go downstairs to mess about with the heating.

All will be sorted correctly when I clean out and rebuild the whole system; and fit a new controller; and a magnetic cyclone filter; and a twin coil hot water tank for solar input etc etc.

But that's a job for the summer.

 

Edited By John Doe 2 on 02/02/2023 19:10:02

[OldironParticipant @oldiron]

Hi John Doe 2. Did I miss something here. Your boiler should have a way to time the heating & hot water seperatley ie a dual channel timer.

You should be able to have the water off & the heating on at different times using the timer. OR is the boiler only running on its internal timer ? these are usually only single channel.

regards

Edited By Oldiron on 02/02/2023 19:37:55

[Les Jones 1Participant @lesjones1]

If the tank is upstairs then you can probably do the work to insert a valve just by partly draining the system. You may not need to drain it any lower than the top of the upstairs radiators. A picture of the pipework around the hot water cylinder would be helpful.

Les.

[John Doe 2Participant @johndoe2]

The heating system I have "inherited" is of unknown quantity, but there are some dubious aspects to its construction.

Therefore I do not wish to disturb it during the winter and risk putting it out pf action completely.

I have worked on home central heating systems and have installed whole or part systems from scratch, so I have plenty of experience in that.

But I do not wish to partly or fully drain the system right now, as I have no doubt that doing so will cause or reveal other problems, which will put the system out of action and require too much disruption and work that I do not have time for at the moment.

The (old) controller does not allow different timings for HW and CH. Both are either off, continuous, twice or once, but the timed periods are the same for both. When I rebuild the system, I will be fitting a modern control system, allowing complete flexibility, cleaning out all the pipework, installing a magnetic cyclone filter, installing a new HW cylinder to accommodate solar water heating, etc etc. This was only ever intended to be a temporary, (and very approximate), fix.

My question was not how to fix my heating system, but about squeezing copper tube.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John Doe 2 on 03/02/2023 08:33:02:

The heating system I have "inherited" is of unknown quantity, but there are some dubious aspects to its construction.

[…]

My question was not how to fix my heating system, but about squeezing copper tube.

.

Short answer, from one lacking your extensive experience: I wouldn’t risk it

… What would be the result if the offending tube were to spli ?

MichaelG.

[DalboyParticipant @dalboy]

Could you not just use a plumbers freezing kit and insert a reducer into the system no need to drain the system at worse you will end up with a very small amount of air when you allow the flow to return.

[Trevor Johnson 1Participant @trevorjohnson1]

John, check out Aladdin Easy Fit Isolator, if you use one of these you will not have to drain your system and will be able to control the flow.

Hope this helps.

[HowiParticipant @howi]

Seems he has his method i.e squeeze the pipe, set in his mind and wants everyone on here to agree with him so he can go ahead. When the pipe DOES split, he can then blame us

I doubt whether he will listen to the advice given here as it is not what he wants to hear.

Best leave it till the better weather is here then bodge it as he see's fit.

Seems to me that if you are seeking advice then one should accept the advice rather than poo pooing (aka Black Adder) the advice given.

[SillyOldDufferModerator @sillyoldduffer]

With my risk management hat on:

• There's a risk John has misdiagnosed the problem and that restricting the flow is the wrong solution. From what John says, he's a 'competent person', therefore the risk is LOW, but John has to be honest with himself. When tackling jobs like this, is the team really competent, or are they are bunch of over-confident cowboys?  (Over confident cowboys don't know they're cowboys!)
• No-one knows how much John's pipe needs to be squeezed, and it can't be un-squeezed. Too little constriction takes the risk of causing damage with no benefit. Too much risks reducing the hot water supply, which is a disbenefit.
• Main point though, squeezing the pipe risks disabling the central heating system mid-winter AND causing a MUST FIX fault. The risks are LOW but the impact is HIGH. (The risk of squeezing a Copper pipe causing a leak is LOW, and the risk of a serious leak is VERY LOW, but the impact is high – water everywhere, system unusable.

The problem here isn't squeezing the pipe, it's managing what happens if squeezing goes wrong, and the action ends in a HIGH impact incident. Like no heating in the middle of a cold snap, water damage because the system drains into the house, and the stop-cock is seized, shops closed, parts out of stock etc.

The mitigation against a HIGH impact incident is to be ready to do the job properly; stop-cock off, system drained, parts and tools ready to go. And if this well-prepared, one might as well do the job properly without risking squeezing at all.

My conclusion is squeezing the pipe is a bodge that could be tried in an emergency, but this problem should be fixed with standard plumbing methods. I think John is living with an inconvenience rather than facing an emergency. Depends on one's 'risk appetite' though. Mine is low on this example, but John's circumstances might make his appetite higher. It's up to him to decide, but when gambling be prepared to take the losses! If you can't do the time, don't do the crime…

Dave

Edited By SillyOldDuffer on 03/02/2023 10:26:59

[John HaineParticipant @johnhaine32865]

Posted by Dave Halford on 01/02/2023 09:41:07:

1970's copper was very poor, even phone cables went over to ali

and look where that got 'em! All degrading rapidly now…  I used to work for Post Office Telecommunications in the early 70s when they were building Milton Keynes.  A great opportunity for the PO to showcase technology so we developed and installed an advanced CATV system, alongside the brand-new aluminium phone cables, so the new residents would have a good phone service and what was then the state of the art in "broadband".  FF 50 years and the aluminium cables are all degraded and I understand that the broadband service in MK is awful.

Edited By John Haine on 03/02/2023 10:50:37

[Adam MaraParticipant @adammara]

And how many of us have gone to do a '10 minute' job that turns into a multi hour nightmare!

[HopperParticipant @hopper]

And most important: Tinkering with the CH system mid-winter and causing a major breakdown in services is NOT the way to win bonus points from the domestic authorities.

[John Doe 2Participant @johndoe2]

Posted by Howi on 03/02/2023 09:48:49:

Seems he has his method i.e squeeze the pipe, set in his mind and wants everyone on here to agree with him so he can go ahead. When the pipe DOES split, he can then blame us

I doubt whether he will listen to the advice given here as it is not what he wants to hear.

Best leave it till the better weather is here then bodge it as he see's fit.

Seems to me that if you are seeking advice then one should accept the advice rather than poo pooing (aka Black Adder) the advice given.

 

Absolutely nothing could be further from my mind.

I was simply asking you guys – experienced in forming and bending metal – if a piece of copper tube would be easily squeezed.

Any action I took would be at 100% my own risk.

Yes, this is an odd solution, and I do think laterally, but I have explained about four times why I do not want to drain the system to install a conventional valve just at the moment – or install a new controller just yet.

Adam and Hopper, above, understand my caution.

However, when the weather is warmer, I will be completely renovating and remodelling the system correctly to a very high quality of workmanship, including re-siting some components for easier access and maintenance, and getting the floors up to cure the cracking sounds as the pipes expand and contract.

If you had bothered to fully read my posts you would see that I HAVE taken the forum advice and will NOT be squeezing the tube.

 

 

Edited By John Doe 2 on 04/02/2023 09:00:30

[John Doe 2Participant @johndoe2]

@SoD Yes, my approach to any problem is first a period of assessment; gathering data and gathering ideas.

Working out the cause of the problem, thinking through each possible solution, trying some adjustments, along with a risk assessment and a cost/benefit analysis of possible courses of action.

I never just wade in and start attacking anything without carefully thinking it through and considering the consequences of things going wrong.

16 years trained by the BBC followed by 19 years trained as an airline pilot, has given me a reasonable amount of experience of a wide range of electronic and engineering systems, and risk assessment !

 

 

Edited By John Doe 2 on 04/02/2023 09:31:15

[SakuraParticipant @sakura]

I'm surprised nobody has suggested the common plumbers trick of blocking the head tank outlet and the system vent (kits are available) and draining down locally, a pint or so,, and then cutting the pipe and installing a valve. I've done it several times.

[John Doe 2Participant @johndoe2]

Sorry, forgive me; there's a limit to how many times I can repeat myself………..

Edited By John Doe 2 on 05/02/2023 17:20:49

[Author]

Posts