The basic performance of the pressure reducing valve: (1) pressure regulating range: it refers to the adjustable range of pressure reducing valve output pressure P2, within the scope of this requirement to achieve the required accuracy. Regulating the pressure range and the main spring stiffness. (2) Pressure characteristics: It refers to the flow rate g is set value, due to input pressure fluctuations caused by the output pressure fluctuations. The smaller the output pressure fluctuation, the better the characteristics of the pressure reducing valve. The output pressure must be lower than the input pressure - the setting will not substantially change with the input pressure. (3) flow characteristics: It refers to the input pressure - timing, the output pressure with the output flow g changes in the holding capacity. When the flow rate g changes, the output pressure changes as small as possible. The lower the general output pressure, the smaller it fluctuates as the output flow changes. Pressure reducing valve design standards: Standard Code Standard Name JIS B3372-1982 Pressure reducing valve for compressed air JIS B8410-1990 Pressure reducing valve for watercourse GB / T 10868-1989 Knowledge of temperature reducing valve for power station GB / T 12244-1989 Pressure reducing valve general conditions GB / T 12245-1989 Pressure reducing valve West to test method GT / T 12246-1989 Pilot-operated pressure reducing valve CB / T 3656-1994 Water pressure reducing valve CB / T 3656-1994 Marine air pressure reducing valve ASTM F1370-1992 Marine Water Supply System Pressure Relief Valve JB / T 53265-1994 Pilot Relief Valve Product Quality Grades AWWA C511-1992 Pressure Relief Backflow Valve Assembly