question on expansion loops

[mark_mc]

have to install expansion loops and iron pipework 1".

can the expansion loops be done in threaded fittings or do they have to bent in a bender one peice.
any ideas

 

[GQuigley67]

what about installing expansion bellows ?

 

[SimonJohns]

I always thought these were bent. Or mainly bought due to the tight bends.

Is someone giving you a spec for this. I wouldn't want to be making it without someone taking the bullet for liability.

Btw. Put unions either side and valves if poss. When these go thru work hardening. It makes life alot easier to replace them

 

[mark_mc]

no bellows not allowed to use.
have the measurement and have them in but used threaded fittngs but someone told me to bend them looking for advice if the threaded loops with do.

 

[SimonJohns]

no bellows not allowed to use.
have the measurement and have them in but used threaded fittngs but someone told me to bend them looking for advice if the threaded loops with do.

Only issue with threaded fittings to construct shapes of loops is that you dont get a uniform movement. You will find that it is more proud around the fittings and will cause premature failure

What style loop are you putting in?

 

[turnpin]

Used to bend these with sand and oxy acetelene when I was younger much easier with hydraulic bender these days what is going through the pipe ? mine were all carrying steam.Regards turnpin

 

[ecowarm]

I have fitted expansion loops with fittings and also bent as turnpin, I dont think the expansion will cause the fittings to fail

 

[GQuigley67]

when we done expansion loops we done them in fittings, this was water services though not heating, but i found that most jobs we used bellows, any particular reason why they are not allowed ?

 

[stevetheplumber]

allways bent but i havent used one for twenty years now mostly linear exspansion joints now
i assume its buried so needs to be maintainence free?

 

[mark_mc]

just not allowed to use bellows the consultant wants loops.
it wasnt the consultant that wanted them changed but are boss. he maintains that the fitting would spilt and with todays fitting i wouldnt be surpised.
have order a bender from hss hire and im going to bend them, i think your right bout the uniform expansion if your even a couple of mm out it would intend to expand on one side only and cause failure.