Having spent some time learning to double flare from the help above and other sources, I’ll summarise what I’ve found that works for me in case it helps any other flaring-novices later.
This is based around using a standard type flaring tool – in my case a “Sealey AK506 Pipe Flaring & Cutting Kit 10pc”:-
www.sealey.co.uk/popupimage.htm?Images/Products/AK506.V2.pngHere’s the process I ended up with for double flaring. It may be excessive to those who know what they’re doing, but it works consistently for me:-
1. Cut the pipe squarely with a pipe cutting tool (not a saw or anything that can stray from a right angled cut).
2. Put a pipe union fitting on the pipe the right way round before flaring! Keep it near the end of the pipe because it won’t move over any bends you put in the pipe to get it back to the end of the pipe later.
3. Ream/debur the inside of the pipe back to its original internal diameter.
4. File the end of the pipe flat whilst keeping the cut square. One way to do this well is to put the pipe in the flaring tool, but the wrong way round (i.e. slightly emerging on the flat side of the tool) and file across it there.
5. Quick debur of inner again if necessary.
6. Chamfer the outside of the cut – only a slight chamfer is needed.
7. Insert the pipe in the pipe flaring tool. To measure the correct amount of pipe to leave protruding; measure it against the wider diameter part of the appropriate die.
8. Secure flaring tool clamps tight without using additional leverage (for this Sealey tool anyway) making sure the two sides are level and not offset.
9. Consider putting a piece of masking tape around the pipe under the tool and up against the tool – as a mark to be able to check that the pipe has not been pushed through the tool during the flaring process.
10. Lubricate and insert the appropriate die.
11. Install the pressing part of the tool squarely over the die and tighten it until there’s contact with the die and the feet have come up against the underneath of the tool deck. Then rotate the press clockwise to hit the sides of the tool deck - so that it won’t move when it’s being tightened.
12. Smoothly tighten the press right down until the die has hit the tool deck.
Single flare done.
13. Remove the press and the die.
14. Tighten down the press with no die, just its cone (lubricated) for the double flare. For my flaring tool it takes about one whole turn to produce a double flare 6.8mm across (7mm has been recommended above). Flares can be measured in situ and flared further with care if necessary.
15. Don’t forget to flush out swarf from the pipe before installing.
... now I just need to hear back from Serenco about what they think was wrong with their Powerhand tool (or my use of it).
