60 to 80mesh is recommended for liquid or gas application.
"Primary pressure regulating valve" is installed as a relief valve for the pump in the air conditioning facilities for high-rise buildings adopting the open circuit method. "Differential pressure regulating valve" is installed in the facilities adopting the close circuit method, where a pump needs to run at the stable flow rate regardless of the back pressure. GD-20R primary pressure regulating valve and GD-21 differential pressure regulating valve are the major products in our product lineup.
It is designed to seal the water by the gasket on the cap, so water leak from the screw at the time of adjustment is not abnormal.
Refer to "Pressure Sustaining Valve Sizing Check."