For what it’s worth- I know many of us have pcp fill rigs off of eBay along with used fire carbon fiber scba tanks. There really isn’t a good way to check the pressure except to guess what pressure equates to 60, 50, or 40 min of air. So with that said, Amazon (as well as AOA and other sites) has a foster plug that you can use to seal the end of your full hose and check the pressure of air in your tank - just put the plug in the female end of the hose and slowly open the tank until max pressure is reached to check. After, shut the valve off, bleed the air and remove the plug. Just make sure it’s tight when you check the pressure or it becomes a 50cal slug! Hope it helps
Outdoor Guy Paintball Airsoft PCP Connection Hex 8MM Quick Connect Male Dust Plug/Blind Plug X2 PCS https://www.amazon.com/dp/B07GYJ194F/ref=cm_sw_r_cp_api_uud8BbE764EJ0
Outdoor Guy Paintball Airsoft PCP Connection Hex 8MM Quick Connect Male Dust Plug/Blind Plug X2 PCS https://www.amazon.com/dp/B07GYJ194F/ref=cm_sw_r_cp_api_uud8BbE764EJ0
