Hi,

2 x 3/4" NPT brass unions
6 x 1/2" NPT brass unions

The 3/4 are fine - no leaks at all, the 1/2" unions a different story, the basic problem is not alignment I believe it's tightening torque, even though the unions are staggered using nipples of different lengths, The access to the union hex nut is really limited, tried various sized ridged pipe wrenches, plumbers pliers, the parallel jawed ridged adjustable wrench and just can't get the drips to stop on 3 from 6. Was wondering if anyone knows a slim but strong wrench key made specially for unions in tight regemented formation, any help anyone could offer would be very much appreciated.



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Because when some unions are manufactured, they are machined to match the seal of the opposite piece. In other words do not disassemble unions and mix the seating surfaces. Each union is a pair of matched machine surfaces. This is assuming you are using all brass pieces. If you have a union with a rubber seal, this does not apply. But to be safe, keep those types together to keep things simple.

1/2 inch brass unions should not need anything bigger than a 12 inch channelocks.
take them apart and use some 100% silicone grease. especially where the big nut drags against the end below it.
this doesn't seal anytning as the seal is made by squeezing the mated surfaces together. it does make things slipperier so they tighten better.

Confirm all unions are matched per supplied, good thought though. The problem I'm sure relates to the Kohler 6 port valve outlet lines (6) having 1-3/4" between centers so access for regular tooling is limited to say the least.

Last night I had the thought to pull all 6 lines from the valve unit, tighten them on the vice and pressure test them before reinstalling and not move the unions after gas integrity test, thread them back into the valve unit and resolver the outlet side connections, but then I thought about future maintenance and may opt to replace all 6 unions with compression couplings or sweat unions, that would open up the space for future loosening / re tightening as I'm sure this will be needed every 3-5 years due to the valve being O'ring dependent.

Also thought about double open ring spanners, but try finding a 1-11/16" on the market, but one offers them

Appreciate you support, thank you

Thanks for sharing your wisdom, I had channel locks 8,10 & 12" top notch quality, the space available does not lend its self to get channel locks to rotate the union nut (pipe centers are 1-3/4", the only tool I could think of that would be effective in such a tight spot is a double open ring spanners, slip in at the 1/2 copper location and slide along onto the union nut, the nut is 1-11/16, (just a tad on the large side but a 1-5/8" won't fit) problem is finding a supplier for this fairly big spanners. Now looking at replacing all 6 brass unions with sweat type or compression to enhance the access to loosen or tighten factor for future trouble free maintenance. Thanks very much for sharing your wisdom and offer to help, appreciate your view on this concern.



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Watts makes a copper x brass union that use a rubber gasket to seal which may work for you. Much more forgiving than a ground joint union and needs less torque to tighten up and to take apart. A little pricey.

[www.watts.com]


Good luck.