John,I have yet to find an M10x1.0 to 1/8NPT or even 1/4NPT fitting rated for the pressure we need. They probably exist, I just quit looking for them. You could probably find valves and checks with M101.0 threads, again, I quit looking.You could go with foster fittings, use them to attach valves or checks. This just adds more possible failure points...Don't over think or complicate the high side filter... I nearly did the same when I first got mine Here's my set up. compressor Hose threaded into the included black high side filter. Black filter threads into the bottom of the Gold filter, this black filter is nothing more than a pre-filter for the Gold one. For the discharge, I used the M10x1.0 male foster that came with the Gold filter. I use a double female foster micro bore hose to connect filter to tank. I don't have a pressure maintaining valve, my tanks are always above 1800PSI...
John,With these compressors, you MUST bleed off the pressure from the hose at the very least. You don't want to start the unit up with pressure on the piston...Yeah, you could put a shut off on the intake and discharge of the gold filter and isolate the pressure in it. You save a minute or so of fill time by doing this.... just not worth the money spent to do it or the extra possible leak points IMHO.
https://www.discounthydraulichose.com/9235_Metric_x_NPTF_Female_p/9235.htmhttp://rt21trading.com/catalog/index.php?dispatch=products.view&product_id=30675http://mdmetric.com/Just to name a few.
Isn't that for compression tube fittings, the 1500?