Review on NANPU 0.75-inch NPT Air Drying System - Dual Air Filters & Pressure Regulator Combo with Semi-Automatic Drain and Poly Bowl by Mark Harrison

I was really impressed with this unit. The kit included all the accessories I needed, tape (although it's very flimsy), and everything came mostly assembled. The way they designed it makes each module interchangeable. I actually removed the gauge module to check the pressure, everything worked great without the filters attached. The supplied instructions are very short and poorly translated. Luckily everything is marked with flow arrows on top of each module and there are blocking and pressure increase/decrease instructions on the regulator. Two reasons I gave it 4 stars instead of 5: filter dump valve assemblies and a small air leak. * With my small airbrush compressor, the drain valves do not close by themselves. I have to manually keep them closed for the filters to build up pressure to keep them closed. It's a bit annoying, but it still works. * I also have problems with fittings and pressure holding modules (compressor output is 57 psi, gauge is about that). With tape and fittings included, I can't hold the pressure. I have a slow leak that shortens my compressor cycles. All fittings are tight except for the pressure gauge which is very difficult to reach with a wrench due to the small gap between the pressure gauge and the body. I hand tightened it as much as possible. Manufacturer Recommendations: * I would recommend either including a thin wrench to tighten the gauge with, or having the gauge installed at the factory. * I would replace the piping with something stronger. If it's leaking at 60psi I can imagine what others are experiencing. * Replace the spring in the dump valves to allow low pressure/low flow compressors to close the valves without manual intervention.