Redo flare?

[lomb]

How many times can a correctly made and correctly torqued flare be disassebled and reassembled on 3/8 pipe?
Obviously on 1/4 inch its probably never from experiance but on 3/8 can they be undone and redone once or twice?

[monkey spanners]

Two or three times i would think but if it is something that needs regular disconnecting you can get a braze in brass flare that you use a new copper washer with everytime. Much better imho.
You get a feel for how a flare does up, some do up nice with the nut getting progressively tighter, others just feel like they have come to a dead stop, these are the ones that the copper has become work hardened and a new pice of pipe or anealing the old one is the best coures of action.

If in doubt, chop it out!

[Tesla]

From experience on a correctly ROLLED (not drawn) flare, with a little oil for lubrication - well over ten times. I have found that less than 10% of technicians carry/use a rolling toll to form the flare, the others mainly use a draw type of flaring tool which work hardens the copper more than rolling.

[lomb]

thanks for that. ive had bad luck redoing up 1/4 inch flares with the pipe wanting to pull out and straighten the flare on tightening quite often. i now cut these off and redo as i find it impossible to know if it is good. 3/8 and 1/2 seem meatier and more durable.

another question! flare sizes for 1/4 inch pipe are 8.7- 9.1mm and for 3/8 i think its 12.5-13.1mm, ive measured mine cut with the mastercool eccentric rolling flare cutter and with the pipe level according to instructions it gives a flare of 8.3 mm measured with a caliper. only leaving the pipe out 2mm gives anywhere near the correct dimension. the 8.3mm ones ive cut dont leak but what about the long term?

[lomb]

ps its a r410a flare cutter as its got the purple neck band and was sold as such.

[monkey spanners]

I just do them by eye, never have measured the trumpet (note use of technical term...)

[damo567]

I have stopped making flares. I just cut them off and use a LOKRING flare fitting with copper bonnet. If I ever have to undo them I just replace the bonnet.