How many times can the constant pressure valve 15 air pressure be played?

230 to 250. Constant pressure valve 1 can be used for 15 to 16, and constant pressure valve 15 can be used for 230 to 250. So there is a nut on the constant pressure valve, which can be used to adjust the constant pressure. After loosening the nut and increasing it, the gap between them will also be enlarged, and the pressure will increase, so you can play more constant pressure valves.