Solid Brass 3-Port Air Compressor Check Valve M10*1 x G3/8" x G1/2" Male Female Threaded Tube Connector Non-Return Valve...

Excelente

The smaller of the two compression fittings is M6 thread. The M6 nut and ferrule comes with it. It will hold a 1/4 tube just fine. The larger of the two compression fittings does NOT come with the compression nut. It is 21/32 thread (within .001 when measured). It is not metric, unless someone out there sells a metric nut between 16mm and 17mm. I was unable to source a nut that size anywhere including online. It most fit certain model compressors, but not my old Central Pneumatic from Harbor Freight. I was, however, able to tap the inside if that fitting to 1/8NPT and then put another brass fitting from the hardware store on it that would connect to my 3/8 copper tube. So I made it work, but it was significant effort.

The smaller of the two compression fittings is M6 thread. The M6 nut and ferrule comes with it. It will hold a 1/4 tube just fine. The larger of the two compression fittings does NOT come with the compression nut. It is 21/32 thread (within .001 when measured). It is not metric, unless someone out there sells a metric nut between 16mm and 17mm. I was unable to source a nut that size anywhere including online. It most fit certain model compressors, but not my old Central Pneumatic from Harbor Freight. I was, however, able to tap the inside if that fitting to 1/8NPT and then put another brass fitting from the hardware store on it that would connect to my 3/8 copper tube. So I made it work, but it was significant effort.

This is a 5-star product with a 2-star description. I was replumbing an older Hitachi compressor with a 3/8 NPT output port, and all my other fittings are NPT, so I spent $20 on NPT-to-G adapters to make it work. But it turns out that the threads on this valve are NPT (3/8 input and 1/2 output), not G (BPPT) as in the description. I didn't need the adapters. Oh, and the relief port has a 10 mm nut but takes 6 mm (.236") OD tubing. I tried 1/4" (.250") but it would not fit in the ferrule. Once I finally got everything together the valve seems to work fine.

This is a 5-star product with a 2-star description. I was replumbing an older Hitachi compressor with a 3/8 NPT output port, and all my other fittings are NPT, so I spent $20 on NPT-to-G adapters to make it work. But it turns out that the threads on this valve are NPT (3/8 input and 1/2 output), not G (BPPT) as in the description. I didn't need the adapters. Oh, and the relief port has a 10 mm nut but takes 6 mm (.236") OD tubing. I tried 1/4" (.250") but it would not fit in the ferrule. Once I finally got everything together the valve seems to work fine.