闸阀是最常用的截断阀之一，主要用来接通或截断管路中的介质，不适用于调节介质流量，闸阀适用的压力、温度及口径范围很大，尤其适用于中、大口径的管道。1、闸阀的主要优点(1)流体阻力小，闸阀阀体内部介质通道是直通的，介质流经闸阀时不改变其流动方向，因而流动阻力较小(2)启闭较省力，启闭时闸板运动方向与介质流动方向相垂直，与截止阀相比、闸阀的启闭较为省力。(3)介质流动方向一般不受限制。介质可从闸阀两侧任意方向流过，均能达到接通或截断的目的。便于安装，适用于介质的流动方向可能改变的管路中。150Lb连接尺寸和外形尺寸150LbExternalandconnectingdimensions（mm）公称通径NPSNorminaldiameter单位UnitLDTGCn-ФWHinmm1/2〞15mm10889123560.54-1590188in4.253.50.471.382.384-0.593.547.403/4〞20mm117981243704-1590202in4.613.860.471.692.764-0.593.547.951〞25mm127108125179.54-15100225in54.250.4723.134-0.5948.8611/2〞40mm16512714.37398.54-16200362in6.550.562.883.884-0.62814.252〞50mm17815215.992120.54-19200409in76.000.6253.624.754-0.75816.121/2〞65mm19017817.5105139.54-19250500in7.570.694.125.504-0.751019.683〞80mm20319019.1127152.44-19250570in87.500.75564-0.751022.584〞100mm22922923.9157190.58-19250590in990.946.197.58-0.751023.66〞150mm26727925.4216241.58-22300630in10.501118.59.508-0.881224.88〞200mm29234328.5270298.58-22350960in11.513.501.1210.6211.758-0.8813.8837.810〞250mm33040630.234236212-254001158in1316119812.7514.7512-115.745.612〞300mm35648331.838143212-254501378in14191.25151712-117.754.314〞350mm3815333541347612-295001543in15211.3816.2518.7512-1.279.760.7516〞400mm40659736.6470539.516-296001738in1623.51.4418.521.2516-1.1223.668.4300Lb连接尺寸和外形尺寸300LbExternalandconnectingdimensions（mm）公称通径NPSNorminaldiameter单位UnitLDTGCn-ФWHinmm1/2〞15mm-14095153566.54-15100201in5.513.740.591.382.624-0.5947.913/4〞20mm152117164382.54-19100212in5.984.610.621.693.254-0.7548.351〞25mm1651241851894-19140237in6.54.90.7123.54-0.755.519.3311/2〞40mm19015620.773114.54-22200407in7.56.120.812.884.514-0.88816.022〞50mm21616522.3921278-19200424in8.56.50.883.6258-0.75816.721/2〞65mm24119025.41051498-22250265in9.57.514.125.878-0.881018.313〞80mm28321028.5127168.58-22250535in11.258.25101256.628-0.8810214〞100mm30525431.81572008-22250615in12101.256.197.888-0.881024.26〞150mm40331836.621627012-22350795in15.87512.51.448.510.6212-0.8814031.38〞200mm41938141.327033012-254001012in16.5151.6210.6212.9912-115.739.910〞250mm45744447.7342387.516-294501231in1817.501.8812.7515.2516-1.1217.748.5600Lb连接尺寸和外形尺寸600LbExternalandconnectingdimensions（mm）公称通径NPSNorminaldiameter单位UnitLDTGCn-ФWHinmm2〞15mm29216525.4921278-19250458in11.56.513.6258-0.75101821/2〞20mm33019028.61051498-22250485in137.481.134.125.878-0.881010.093〞25mm35621031.8171688-22250570in148.251.2556.628-0.881022.584〞40mm43227331.81572168-25350690in1710.751.56.198.58-11427.26〞50mm5593564.721629212-29450910in22141.888.511.5012-1.121835.88〞65mm66041955.627034912-325001064in2616.52.1910.6213.7512-1.2517.741.9)