compression fittings

[Kyle87]

ive heard a lot lately about flexis and pushfit. and there seems to be a mutual agreement between forum members in that soldered joints are the best. what about compression fittings. apart from the sheer cost....is there any other draw backs to compression joints?

thanks

 

[PlumbBobBob]

not to be used in a situation where they are hidden i.e. under floors, in walls etc.

 

[AWheating]

size, access to tighten and maintenance, more problematic if fitted poorly. but the mainly cost and time i guess.

 

[Kyle87]

not to be used in a situation where they are hidden i.e. under floors, in walls etc.

thanks for that because i was under the impression that it was just valves you couldnt hide. i had it in my head that for instance, a comp elbow or stop end would be fine under floorboards etc

 

[AWheating]

compression has been used for years under floors without problems, but end feed has so many advantages over it its not the done thing today to use compression. of course if the pipe your dealing with is live or cant be emptied of water fully compression may need to be used.

 

[Best]

A bit mad, or just lazy to fit compression below floors etc, but been done for years. Always more risk of them weeping, but if done right & IMO, paste used they should be sound. Brass can corode, particularly on modern so called brass.
Good place for them is on a heating pipe (usually won't corrode on a decent heating system) that will need removed someday, like a connection that is going in front of a cylinder etc.
So, brass joints for above floors, in places like final connections to sink taps, cylinders, boilers, all the rest solder if possible.

 

[dontknowitall]

... all the rest solder if possible.

That's the crux of the matter - not always possible to solder everywhere so you end up having to use a compression (or push fit) joint. It's not illegal to use compression, just sensible to solder.

 

[Alanka]

Another drawback with compression fittings is their bulkiness compared to solder fittings. Sometimes where space is tight this can be a decider -- especially with elbows. I agree about needing more room to fully tighten the compression backnuts -- 'spanner access'. Another drawback sometimes is the tendency of the pipes to rotate as you tighten the backnuts -- you may need a third hand to prevent this from happening: one to turn the spanner, one to hold the fitting, and a third to prevent pipe rotation! Otherwise you may end up by loosening an existing fitting as you tighten up your one.

 

[Simon F]

for water as said best practice to solder, for under ground pipe if compression would have to be a type b fitting
for gas pipe yes to comply with regs only soldered joints were hidden, compression is ok where visible

 

[dontknowitall]

for water as said best practice to solder, for under ground pipe if compression would have to be a type b fitting
for gas pipe yes to comply with regs only soldered joints were hidden, compression is ok where visible

Compression only (standard fittings with copper inserts) on oil above and underground.

 

[Guest123]

Good quality compression fittings such as Kuterlite 600 are excellent. The cheap imported ones are terrible and have no consistency in getting and maintaining a watertight seal. I can tighten a Kuterlite and forget about it as it wil be sound.

The one advantage that compression has over soldered is that there is no flux and excess solder that can contaminate the pipework and appliances, although this should thoroughly flushed out from soldered pipework, there is always the chance that a bit of solder can dislodge and get inside a pump or a shower and can be a nightmare to remove.

Kuterlite 600 fittings can be used with plastic pipe if copper olives and the correct inserts are used. There is also a dzr range for dezincification.

 

[royston]

It surprises me how some people think that copper and soldered fittings are bomb proof ! Ive come across loads of soldered fittings that have become brittle and leaked, and copper pipe that's corroded and leaked.

 

[Roger Welton]

Compression only (standard fittings with copper inserts) on oil above and underground.

Or flared (I know it's a type of compression), and any underground joints to have access for inspection