GB / T 1047-2005 standard, the valve nominal diameter just a logo, represented by a combined symbol “DN” and numbers do not represent the nominal size of the valve diameter measured values, the actual diameter value of the valve consists of the standards-related provisions generally found (in mm) not less than 95% of the nominal value of size. Nominal size fraction Metric (symbol: DN) and imperial (symbol: NPS), GB valves metric, the US standard valve to English. Metric DN values ​​are as follows:
Preferred DN values ​​as follows:
DN10 DN15 DN20 DN25 DN32 DN40 DN50 DN65 DN80 DN100 DN125 DN150 DN200 DN250 DN300 DN350 DN400 DN450 DN500 DN600 DN700 DN800 DN900 DN1000 DN1100 DN1200, DN1400, DN1600, DN1800, DN2000, DN2200, DN2400, DN2600, DN3000, DN3200, DN3500, DN4000
GB / T 1048-2005 standard, the valve nominal pressure is a logo, represented by a combined symbol “PN” and numbers can not be used to calculate the nominal purpose, does not represent the actual measured value of the valve, nominal purpose is to establish simplifying the number of pressure valve specifications, in the selection, design units, manufacturing units and the use of units of this provision are to follow the principles of the nearest data by the nominal purpose of the establishment is the same size. Nominal divided European system and the American system. China’s nominal pressure is to use the European system standards. Specifications are as follows:
PN0.1, PN0.6, PN1.0, PN 2.5 PN6 PN10 PN16 PN25 PN40 PN63 / 64 PN100 / 110 PN150 / 160 PN260 PN320 PN420
CLASS: 125LB, 150LB, 300LB, 400LB, 600LB, 900LB, 1500LB, 2000LB, 2500LB, 3500LB, 4500LB