18kw with 7/8 flare

[wombat]

A colleague asked for me to connect the pipes to a Transco 18kw ducted yesterday, then pressure test and evacuate. But these units have 7/8" & 1/2" flare connections and use R410A. The 1/2" is no problem, but finding a 7/8" flaring block and torque spanner is not easy.
Normally 3/4" is the largest flare seen on units and 7/8" would be hard drawn copper and soldered.
Has anyone had experience in connecting this size pipe with R410A? Are flaring tools and torque spanners available in Sydney,Australia?
Any help would be appreciated.

[Argus]

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That's an oddball size of flare these days. I haven't seen flares bigger than 3/4" for many years - I didn't know that they are obtainable greater than that. As a matter of interest, who made the kit?

I have an old flare block dating from the 1940's (it's a museum piece, really) that I used occasionally to make 3/4" flares, it also contains a 7/8" and 1" flare size, but I've had it now for over 40 years and I've only ever used the 3/4" - except for the 1" size once on an old Weir compressor to renew the discharge pipe flare - and that was back in the 1960s. But before you get excited - I'm in the UK!

The Japanese sometimes provide 1" pipe connections (a size of pipe which is virtually unobtainable in this part of the world) but it's all braze, these days.

I think you should investigate brazing, if it's possible.

.

[thermo prince]

hi Wombat, might be worth a try to contact TRS , the TK dealer in Blacktown area. In earlier days most of the trailer and bus a/c units used 37deg flare fittings at multiple points on system. Even today large bus a/c use 13/8 suction and 7/8 discharge tubes however fittings have all gone to ORS F( o ring seal) - if I recall correctly that was by law around time of HFC introduction, at least for all transport equipment Flare was banned. Japan did not adhere to this ruling however. See if TRS can help get you some ORS fittings 'to convert'or as Argus says, cut off the flares and sweat cu to cu tube if that is acceptable. Let me know if you need contact and how you get on. Good luck!

[thermo prince]

sorry guys, suction should read 9/8" , not 13/8!

[monkey spanners]

ITE/Imperial Eastman still make the 3/4" 7/8" 1" flaring block, i bought one last month for a Serap Dx milktank that uses a 7/8" connection on the suction. Had to be sent in from Belgium as none in the country. I just heated up some hard drawn copper and allowed it to cool before flaring. This was on R22.

Jon

[wombat]

My colleague found someone who made a flare on each end of a 1m length of 7/8" pipe. This pipe was then cut attached to the indoor and outdoor units and brazed to the pipe.
As expected, both leaked when pressurised with nitro. After several attempts, the outdoor flare stopped leaking at 200 PSI, but the indoor still leaks. I will take your advice Argus and remove the fitting then braze both pipes together tomorrow.
The A/C has the brand name is Transco. Probably made in China. I had a quick look at the rather small installation book, no mention of how tight the flare nuts should be or the use of a vacuum pump with this R410A unit. The word purge was used. I recall purging splits 20 years ago when all units were R22.