collapsed compression joints
after a rather more eventful weekend than i was hoping for, i'm hoping
somebody can explain this.... i finished plumbing in everything in my new bathroom a couple of weeks ago. no real problems and all went quite well. so, i was a bit surprised to be woken at 1am on saturday to the sound of water running and a hysterical girlfriend. it appears that one of the compression joints has spontaneously exploded, allowing mains pressure water to go everywhere. fortunately no real damage done, just a lot of mopping up to do downstairs. the bit i don't understand is why this joint went so suddenly. here's the facts : 1. the pipe had just slipped straight out leaving the olive in the service valve that the pipe had escaped from. 2. the joint hasn't leaked at all in the last 2 weeks. 3. the pipe was running from a service valve horizontally about 4" across then going to a flexi-hose which connects vertically to the adapters which go up to the mixer tap. 4. the pipe wasn't supported by pipe clips, although it's a short run and hardly moves at all anyway. 5. i'd put a couple of wraps of PTFE tape over the olive as i'd been advised that this can help stop small leaks (was this my downfall?) 6. all the other compression joints i've made are absolutely fine and have been for 2 weeks. i'd quite like to understand why this joint has failed so spectacularly before i go trying to fix it. thanks dan |
collapsed compression joints
Redeye wrote:
5. i'd put a couple of wraps of PTFE tape over the olive as i'd been advised that this can help stop small leaks (was this my downfall?) IANAP Best to remove all tape, provided the fittings are clean, unscratched and undamaged. Tighten until the olive just grips the pipe. Add an extra 1/6 turn to compress the olive. No doubt proper plumbers will disagree. john2 |
collapsed compression joints
Redeye wrote:
after a rather more eventful weekend than i was hoping for, i'm hoping somebody can explain this.... i finished plumbing in everything in my new bathroom a couple of weeks ago. no real problems and all went quite well. so, i was a bit surprised to be woken at 1am on saturday to the sound of water running and a hysterical girlfriend. it appears that one of the compression joints has spontaneously exploded, allowing mains pressure water to go everywhere. fortunately no real damage done, just a lot of mopping up to do downstairs. the bit i don't understand is why this joint went so suddenly. here's the facts : 1. the pipe had just slipped straight out leaving the olive in the service valve that the pipe had escaped from. snip i'd quite like to understand why this joint has failed so spectacularly before i go trying to fix it. Because you diddn't tighten it up enough. The olive should form a tight metal-metal seal, with no need for PTFE. The only case where PTFE is actually needed is if you've got damaged pipework, or fittings, and can't really replace easily. You should _NOT_ be able to 'pull' the pipe out as happened in this case, without actually damaging the fitting, and exerting much, much more force than it saw. |
collapsed compression joints
john2 wrote:
Redeye wrote: 5. i'd put a couple of wraps of PTFE tape over the olive as i'd been advised that this can help stop small leaks (was this my downfall?) IANAP Best to remove all tape, provided the fittings are clean, unscratched and undamaged. Tighten until the olive just grips the pipe. Add an extra 1/6 turn to compress the olive. No doubt proper plumbers will disagree. john2 Th olive should be tightened enough to permanently deform the pipe. In practice you can keep on going till you can't go no more, but somewhere in between 'just leakproof' and 'fully home' is a happy medium. I am not sure how I do it, but in practice when screwing up they get tighter and tighter and then they don't get any harder to turn at all.that mean you are now deforming the copper, not taking up the slack, and its time to stop..or add that 1/6th turn for good luck. |
collapsed compression joints
The message .com
from "Redeye" contains these words: i finished plumbing in everything in my new bathroom a couple of weeks ago. no real problems and all went quite well. so, i was a bit surprised to be woken at 1am on saturday to the sound of water running and a hysterical girlfriend. it appears that one of the compression joints has spontaneously exploded, allowing mains pressure water to go everywhere. fortunately no real damage done, just a lot of mopping up to do downstairs. Comiserations. Happened to my parents in law over Christmas. They'd not even moved into the house fully - just had new carpets and wallpaper etc, and had never even seen most of it fitted. Pipe went while they were away for a week - mains feed to loft tank came apart. Previous owner was a plumber! Just the electricity to dry the house out came to nearly a grand. Thank heavens for insurance. Anyway - never ever put PTFE tape on compression joints. They rely solely on metal to metal contact. If the olive has slipped off the pipe then it wasn't done up properly. -- Skipweasel Pay no attention to that man behind the curtain. |
collapsed compression joints
okay, thanks for the feedback.
i've come to the conclusion that i've followed bad advice which is probably the cause of the problem. i'd also been warned not to overtighten compression joints, but advice here seems to suggest that isn't possible. anyway, i think i'll replace some of my compression joints with push fittings in the hope of avoiding a repeat disaster (although i've got a push fit joint leaking slightly at the moment as well !!). |
collapsed compression joints
In an earlier contribution to this discussion,
Redeye wrote: i'd quite like to understand why this joint has failed so spectacularly before i go trying to fix it. As others have said, it wasn't done up properly - and don't use PTFE tape! If you're not sure when it's tight enough - and you get used to the 'feel' when you've done a few - do it up and then take it apart again and check that the olive is firmly crimped onto the pipe. If you want a belt and braces job, smear a bit of Boss White (not PTFE tape) round the olive before you re-assemble it - but that shouldn't be necessary on a new fitting with new pipe. -- Cheers, Roger ______ Email address maintained for newsgroup use only, and not regularly monitored.. Messages sent to it may not be read for several weeks. PLEASE REPLY TO NEWSGROUP! |
collapsed compression joints
The message .com
from "Redeye" contains these words: i've come to the conclusion that i've followed bad advice which is probably the cause of the problem. i'd also been warned not to overtighten compression joints, but advice here seems to suggest that isn't possible. Well, it is if you're a gorilla... -- Skipweasel Pay no attention to that man behind the curtain. |
collapsed compression joints
Redeye wrote: anyway, i think i'll replace some of my compression joints with push fittings in the hope of avoiding a repeat disaster (although i've got a push fit joint leaking slightly at the moment as well !!). My caution with mains pressured water extends to the belief that properly-installed soldered fittings are the way to go unless the consequences of a failure won't be too damaging. Of course, this then thwarts any changes because they aren't as readily undo-able as compression fittings. I haven't used the new Monsoon 3 bar shower pump yet but its my first exposure to push fittings and I must admit to being quite impressed (with no experience of them this isn't saying much!). That plus the perceived speed in installation as well as easier installation in restricted locations makes push fittings sound interesting... Mungo |
collapsed compression joints
"Redeye" wrote in
oups.com: 5. i'd put a couple of wraps of PTFE tape over the olive as i'd been advised that this can help stop small leaks (was this my downfall?) I think it's this that did you, making you think you had a seal when you hadn't. You should NEVER put jollop on a compression joint (unless, unless...) but in case of a bodge like that - old pipe, short pipe, unremoveable olive etc you will need to muller it well down and make damn sure it won't budge mike |
collapsed compression joints
Guy King wrote:
The message .com from "Redeye" contains these words: i've come to the conclusion that i've followed bad advice which is probably the cause of the problem. i'd also been warned not to overtighten compression joints, but advice here seems to suggest that isn't possible. Well, it is if you're a gorilla... Or it's 8mm pipe. With 22mm compression fittings, you'll have a job breaking the fitting so that it won't seal by overtightening. It's probably possible, but you'll need a long spanner, and the pipe to be restrained quite securely. |
collapsed compression joints
Redeye wrote: after a rather more eventful weekend than i was hoping for, i'm hoping somebody can explain this.... i finished plumbing in everything in my new bathroom a couple of weeks ago. no real problems and all went quite well. so, i was a bit surprised to be woken at 1am on saturday to the sound of water running and a hysterical girlfriend. it appears that one of the compression joints has spontaneously exploded, allowing mains pressure water to go everywhere. fortunately no real damage done, just a lot of mopping up to do downstairs. the bit i don't understand is why this joint went so suddenly. here's the facts : 1. the pipe had just slipped straight out leaving the olive in the service valve that the pipe had escaped from. 2. the joint hasn't leaked at all in the last 2 weeks. 3. the pipe was running from a service valve horizontally about 4" across then going to a flexi-hose which connects vertically to the adapters which go up to the mixer tap. 4. the pipe wasn't supported by pipe clips, although it's a short run and hardly moves at all anyway. 5. i'd put a couple of wraps of PTFE tape over the olive as i'd been advised that this can help stop small leaks (was this my downfall?) 6. all the other compression joints i've made are absolutely fine and have been for 2 weeks. i'd quite like to understand why this joint has failed so spectacularly before i go trying to fix it. thanks dan I'd guess the pipe was not fully home when you tightened it. The PTFE tape wouldn't have caused it. |
collapsed compression joints
The message
from Ian Stirling contains these words: With 22mm compression fittings, you'll have a job breaking the fitting so that it won't seal by overtightening. It's probably possible, but you'll need a long spanner, and the pipe to be restrained quite securely. Doesn't everyone use two spanners? Perhaps that's where all the people who've been having compression joint fittings are going wrong, they're just using one spanner! -- Skipweasel Pay no attention to that man behind the curtain. |
collapsed compression joints
Guy King wrote:
The message from Ian Stirling contains these words: With 22mm compression fittings, you'll have a job breaking the fitting so that it won't seal by overtightening. It's probably possible, but you'll need a long spanner, and the pipe to be restrained quite securely. Doesn't everyone use two spanners? Perhaps that's where all the people who've been having compression joint fittings are going wrong, they're just using one spanner! Two spanners helps - but you've still got an unbalanced torque left. |
collapsed compression joints
In article .com,
Redeye wrote: i've come to the conclusion that i've followed bad advice which is probably the cause of the problem. i'd also been warned not to overtighten compression joints, but advice here seems to suggest that isn't possible. Use proper open ended spanners and tighten them till they groan. You won't overtighten them unless using something silly like large Stilsons. -- *There are two sides to every divorce: Yours and **** head's* Dave Plowman London SW To e-mail, change noise into sound. |
collapsed compression joints
On 8 May 2006 05:59:05 -0700, "Redeye"
wrote: 5. i'd put a couple of wraps of PTFE tape over the olive as i'd been advised that this can help stop small leaks (was this my downfall?) This is the reason. Compression joints are not PTFE territory. |
collapsed compression joints
Guy King wrote:
[tightening compression fittings] Doesn't everyone use two spanners? Perhaps that's where all the people who've been having compression joint fittings are going wrong, they're just using one spanner! Don't you *have* to use two spanners (or a spanner and a "grip", or two pairs of Stillsons)? |
collapsed compression joints
Chris Bacon wrote:
Guy King wrote: [tightening compression fittings] Doesn't everyone use two spanners? Perhaps that's where all the people who've been having compression joint fittings are going wrong, they're just using one spanner! Don't you *have* to use two spanners (or a spanner and a "grip", or two pairs of Stillsons)? Depends. If it's a valve, or something else assymetric you can hold it with one hand, and sort-of do it up with the other. |
collapsed compression joints
The message
from Ian Stirling contains these words: Doesn't everyone use two spanners? Perhaps that's where all the people who've been having compression joint fittings are going wrong, they're just using one spanner! Two spanners helps - but you've still got an unbalanced torque left. Mitigated with offset spanners. Anyway, it was the self limiting by the user of the applied torque to do up the fitting I was wondering about. With only one spanner even quite inept people will limit the tightness because the other half of the fitting is starting to turn. -- Skipweasel Pay no attention to that man behind the curtain. |
collapsed compression joints
The message
from Chris Bacon contains these words: [tightening compression fittings] Doesn't everyone use two spanners? Perhaps that's where all the people who've been having compression joint fittings are going wrong, they're just using one spanner! Don't you *have* to use two spanners (or a spanner and a "grip", or two pairs of Stillsons)? I'd have trouble doing otherwise, but I was wondering whether failing to do so might be the root of the trouble people are having with compression fittings. -- Skipweasel Pay no attention to that man behind the curtain. |
collapsed compression joints
The Natural Philosopher wrote:
john2 wrote: Redeye wrote: 5. i'd put a couple of wraps of PTFE tape over the olive as i'd been advised that this can help stop small leaks (was this my downfall?) IANAP Best to remove all tape, provided the fittings are clean, unscratched and undamaged. Tighten until the olive just grips the pipe. Add an extra 1/6 turn to compress the olive. No doubt proper plumbers will disagree. john2 Th olive should be tightened enough to permanently deform the pipe. eh ? |
collapsed compression joints
Redeye wrote:
okay, thanks for the feedback. i've come to the conclusion that i've followed bad advice which is probably the cause of the problem. i'd also been warned not to overtighten compression joints, but advice here seems to suggest that isn't possible. it is. |
collapsed compression joints
Ian Stirling wrote:
Guy King wrote: The message from Ian Stirling contains these words: With 22mm compression fittings, you'll have a job breaking the fitting so that it won't seal by overtightening. It's probably possible, but you'll need a long spanner, and the pipe to be restrained quite securely. Doesn't everyone use two spanners? Perhaps that's where all the people who've been having compression joint fittings are going wrong, they're just using one spanner! Two spanners helps - but you've still got an unbalanced torque left. IMEE it's 2 pairs of grips. no spanners. |
collapsed compression joints
mike wrote:
"Redeye" wrote in oups.com: 5. i'd put a couple of wraps of PTFE tape over the olive as i'd been advised that this can help stop small leaks (was this my downfall?) I think it's this that did you, making you think you had a seal when you hadn't. You should NEVER put jollop on a compression joint (unless, unless...) oh, really :-) |
collapsed compression joints
The message
from "." contains these words: Th olive should be tightened enough to permanently deform the pipe. eh ? Seems clear enough to me. The clamping by the nut should tighten the olive onto the pipe sufficiently to indent the pipe all the way round - that's how they work. -- Skipweasel Pay no attention to that man behind the curtain. |
collapsed compression joints
Redeye wrote:
okay, thanks for the feedback. i've come to the conclusion that i've followed bad advice which is probably the cause of the problem. i'd also been warned not to overtighten compression joints, but advice here seems to suggest that isn't possible. I think it is. If you tighten it up as far as it will go, if you need to take the joint apart at any future date you'll have a hard time getting it watertight again as there's nothing left to compress. Tim |
collapsed compression joints
Guy King wrote:
The message from "." contains these words: Th olive should be tightened enough to permanently deform the pipe. eh ? Seems clear enough to me. The clamping by the nut should tighten the olive onto the pipe sufficiently to indent the pipe all the way round - that's how they work. /deform/ the pipe (sic) ? overtightening the joint deforms the /tube/, that's what causes leaks. a /light/ touch of jollop, good control on the static part of the joint and knowing when the joint is nipped up all takes experience and it's for that reason that them who are not dealing with compression joints day in, day out should take the time to learn how to solder a joint. YMMWV, of course. |
collapsed compression joints
.. wrote:
Guy King wrote: The message from "." contains these words: Th olive should be tightened enough to permanently deform the pipe. eh ? Seems clear enough to me. The clamping by the nut should tighten the olive onto the pipe sufficiently to indent the pipe all the way round - that's how they work. /deform/ the pipe (sic) ? overtightening the joint deforms the /tube/, that's what causes leaks. a /light/ touch of jollop, good control on the static part of the joint and knowing when the joint is nipped up all takes experience and it's for that reason that them who are not dealing with compression joints day in, day out should take the time to learn how to solder a joint. YMMWV, of course. If the olive does not indent, how has the joint any mechanical strength at all? ISTR that a compression joint in 15mm is safe to 45 bar, but ICBW. They shouldn't be over-tightened, else wrinkles are a problem, that's why they leak AFAIK. |
collapsed compression joints
On Mon, 08 May 2006 05:59:05 -0700, Redeye wrote:
after a rather more eventful weekend than i was hoping for, i'm hoping somebody can explain this.... i finished plumbing in everything in my new bathroom a couple of weeks ago. no real problems and all went quite well. so, i was a bit surprised to be woken at 1am on saturday to the sound of water running and a hysterical girlfriend. it appears that one of the compression joints has spontaneously exploded, allowing mains pressure water to go everywhere. fortunately no real damage done, just a lot of mopping up to do downstairs. the bit i don't understand is why this joint went so suddenly. here's the facts : 1. the pipe had just slipped straight out leaving the olive in the service valve that the pipe had escaped from. 2. the joint hasn't leaked at all in the last 2 weeks. 3. the pipe was running from a service valve horizontally about 4" across then going to a flexi-hose which connects vertically to the adapters which go up to the mixer tap. 4. the pipe wasn't supported by pipe clips, although it's a short run and hardly moves at all anyway. 5. i'd put a couple of wraps of PTFE tape over the olive as i'd been advised that this can help stop small leaks (was this my downfall?) 6. all the other compression joints i've made are absolutely fine and have been for 2 weeks. i'd quite like to understand why this joint has failed so spectacularly before i go trying to fix it. Either the pipe was not inserted past the olive (it may have been but then pulled out before tightening), in this case the tightening tends to roll the olive over the end of the pipe and tends to expel the pipe. The fitting was in noway adequately tightened. If the pipe/fitting are in good alignment and everything is clean then the back nut will "finger spin" up to the "bite point". After that I would say you are looking at adding 2-4 'flats' (1/3 to 2/3 of a turn to tighten most fittings). HTH -- Ed Sirett - Property maintainer and registered gas fitter. The FAQ for uk.diy is at http://www.diyfaq.org.uk Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html |
collapsed compression joints
Redeye wrote: okay, thanks for the feedback. i've come to the conclusion that i've followed bad advice which is probably the cause of the problem. Probably. You came to the right place for conflicting advice ;-) i'd also been warned not to overtighten compression joints, but advice here seems to suggest that isn't possible. Definitely possible. You can overtighten it enough to damage the pipe (and hence the joint) if you go at it like some gorilla. There's a distinct difference between loose, tight (watertight) and overtight. I think experience has shown you what 'loose' feels like. anyway, i think i'll replace some of my compression joints with push fittings in the hope of avoiding a repeat disaster (although i've got a push fit joint leaking slightly at the moment as well !!). I wouldn't choose pushfit over compression, especially in hot water situations, no matter what 25 year guarantee the pushfit manufacturers give ..... All plumbing with whatever fitting of choice takes practice. It's easy to undertighten a compression if you've not had much experience of them, as much as it's easy to make a bad solder joint. Practice. Then take it apart (compression) or heat up a practice solder joint and separate to check how well the joint has 'wetted'. Then you'll know how much solder is enough .. Cheers Paul. |
collapsed compression joints
|
collapsed compression joints
In article .uk,
Ed Sirett writes i'd quite like to understand why this joint has failed so spectacularly before i go trying to fix it. Either the pipe was not inserted past the olive (it may have been but then pulled out before tightening), in this case the tightening tends to roll the olive over the end of the pipe and tends to expel the pipe. The fitting was in noway adequately tightened. If the pipe/fitting are in good alignment and everything is clean then the back nut will "finger spin" up to the "bite point". After that I would say you are looking at adding 2-4 'flats' (1/3 to 2/3 of a turn to tighten most fittings). The voice of reason from one who does this for a living, respect. -- fred Plusnet - I hope you like vanilla |
collapsed compression joints
The message
from "." contains these words: Seems clear enough to me. The clamping by the nut should tighten the olive onto the pipe sufficiently to indent the pipe all the way round - that's how they work. /deform/ the pipe (sic) ? That's right - deform the pipe. The olive will be pressed into the pipe, deforming it in a ring all the way round. What's wrong with that? -- Skipweasel Pay no attention to that man behind the curtain. |
collapsed compression joints
Guy King wrote:
The message from "." contains these words: Seems clear enough to me. The clamping by the nut should tighten the olive onto the pipe sufficiently to indent the pipe all the way round - that's how they work. /deform/ the pipe (sic) ? That's right - deform the pipe. The olive will be pressed into the pipe, deforming it in a ring all the way round. What's wrong with that? 1/ it's copper /tube/ 2/ if the olive deforms the tube the joint is over tightened and will weep |
collapsed compression joints
In article ,
EricP wrote: 5. i'd put a couple of wraps of PTFE tape over the olive as i'd been advised that this can help stop small leaks (was this my downfall?) This is the reason. No it's not. Compression joints are not PTFE territory. I'm one of those who does use PTFE round the olive. And non of mine leak - and certainly don't pull apart. The only way a compression fitting can pull apart is when it's not properly tightened. -- *Depression is merely anger without enthusiasm * Dave Plowman London SW To e-mail, change noise into sound. |
collapsed compression joints
In article ,
Tim Downie wrote: I think it is. If you tighten it up as far as it will go, if you need to take the joint apart at any future date you'll have a hard time getting it watertight again as there's nothing left to compress. Not so - once the olive is compressed on the pipe it remains compressed. The tapers on the olive and body are then the seal - and if in good condition will seal again ok even if moved round. However, an old fitting may well have some corrosion on the seats due to electrolytic action and if so will be difficult to seal. -- *Constipated People Don't Give A Crap* Dave Plowman London SW To e-mail, change noise into sound. |
collapsed compression joints
In article ,
. wrote: /deform/ the pipe (sic) ? overtightening the joint deforms the /tube/, that's what causes leaks. If it doesn't 'deform' the pipe slightly it isn't correctly made. It's impossible to pull off an olive from a properly made joint, and this wouldn't be so if it was merely friction. -- *(over a sketch of the titanic) "The boat sank - get over it Dave Plowman London SW To e-mail, change noise into sound. |
collapsed compression joints
Dave Plowman (News) wrote:
In article , Tim Downie wrote: I think it is. If you tighten it up as far as it will go, if you need to take the joint apart at any future date you'll have a hard time getting it watertight again as there's nothing left to compress. Not so - once the olive is compressed on the pipe it remains compressed. The tapers on the olive and body are then the seal - and if in good condition will seal again ok even if moved round. However, an old fitting may well have some corrosion on the seats due to electrolytic action and if so will be difficult to seal. .... and that's the one time I put some PTFE tape on the olive. To form a new seat. R. |
collapsed compression joints
Dan,
Temp change, pressure change??? one of those things. Why are you using PTFE tape, Ive never found a need to use it, i allways use new pipes and fittings, there cheap enough esp if you go to a plumbers merchant. Kev "Redeye" wrote in message oups.com... after a rather more eventful weekend than i was hoping for, i'm hoping somebody can explain this.... i finished plumbing in everything in my new bathroom a couple of weeks ago. no real problems and all went quite well. so, i was a bit surprised to be woken at 1am on saturday to the sound of water running and a hysterical girlfriend. it appears that one of the compression joints has spontaneously exploded, allowing mains pressure water to go everywhere. fortunately no real damage done, just a lot of mopping up to do downstairs. the bit i don't understand is why this joint went so suddenly. here's the facts : 1. the pipe had just slipped straight out leaving the olive in the service valve that the pipe had escaped from. 2. the joint hasn't leaked at all in the last 2 weeks. 3. the pipe was running from a service valve horizontally about 4" across then going to a flexi-hose which connects vertically to the adapters which go up to the mixer tap. 4. the pipe wasn't supported by pipe clips, although it's a short run and hardly moves at all anyway. 5. i'd put a couple of wraps of PTFE tape over the olive as i'd been advised that this can help stop small leaks (was this my downfall?) 6. all the other compression joints i've made are absolutely fine and have been for 2 weeks. i'd quite like to understand why this joint has failed so spectacularly before i go trying to fix it. thanks dan |
collapsed compression joints
In article ,
Dave Plowman (News) wrote: In article .com, Redeye wrote: i've come to the conclusion that i've followed bad advice which is probably the cause of the problem. i'd also been warned not to overtighten compression joints, but advice here seems to suggest that isn't possible. Use proper open ended spanners and tighten them till they groan. You won't overtighten them unless using something silly like large Stilsons. Yup, all the joints that I'd convinced myself were leaking cos I'd over-tightened them turned out to be not tight enough. Just an extra 1/8 turn was all that was needed for most of them. G. |
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