... 1,A105 valve seat 2,min OD around 200mm 3,weight of single piece between 50kg and 4t A105 valve seat min OD around ... abundent experience in the manufacture of oil chemical industry forging• 3 workshops occupie20000 square meters, one is gear workshop, the second ... 35#,40#,45#,46#,etc.according to customers' different requirements.3,main material are 5CrMnMo,40Cr,42CrMo,20Cr2Ni4,5CrNiMo,15CrNiMo,20CrNiMo ...