Fixed vs Adjustable Pressure Regulator

Recently, I purchased a fixed-pressure regulator (I bought both the 1200 PSI and 2000 PSI versions), and I would like to share a few observations.

• At first glance, it is clear that the regulator piston in the fixed-pressure regulator is significantly larger, and it uses a much larger stack of Belleville washers. The overall design looks more robust. In the adjustable regulator, the washers appear to be less precisely matched, so I suspect the pressure consistency of the adjustable regulator may be lower.
• In the adjustable regulator, I had to replace the piston o-ring from time to time because it would occasionally become damaged. When operating at pressures up to around 1500 PSI, the o-ring lifespan was noticeably longer. At higher pressures, the o-ring tended to wear out more quickly. If you buy a regulator with a shut-off pin, its service life should be significantly longer, provided that you do not use the adjustment screw as a pressure shut-off valve.
• The adjustment screw threads in my adjustable regulator failed. It was not repairable, so I ended up buying another regulator of the same type. Despite this issue, it is still very useful for testing, as it allows you to easily experiment with a wide range of pressures and observe how the air rifle behaves.
• A fixed-pressure regulator can also be adjusted slightly. I purchased some spacer shims, and by making small changes to the washer stack, it is possible to change the output pressure. I bought a regulator rated at 2000 PSI, but received one that was actually set to 2200 PSI. By modifying the washer stack, I was able to bring the output pressure down to 2000 PSI.

I will try to add more observations as I come up with them. 🙂