國標球閥不銹鋼球心尺寸
DN15:10mm；DN20:15mm;DN25:20mm;DN32:25mm;DN40:32mm;DN50:40mm;DN65:50mm
DN80:65mm;DN100:80mm;DN125:100mm; DN150:100mm; DN200:150mm;DN250:200mm;
DN300:250mm;DN350:300mm;
DN400:337mm; DN500:387mm'DM600:489mm;DN700:A591mm;DN800:686mm;
DN300以下公差0--+0.3；以上+0.1 -- +0.3