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Valve material and valve standards-(4)-fastener material

Fastener materials: Fasteners mainly include bolts, studs and nuts. The fastener directly bears the pressure on the

bolts and nuts for butterfly valve

bolts and nuts for butterfly valve

valve, which plays a key role in preventing the outflow of the medium. Therefore, the selected material must ensure sufficient strength and impact toughness at the operating temperature.

When selecting fastener materials according to medium pressure and temperature, the following table can be selected:

Name Pn(Mpa) medium temp /°C
300 350 400 425 450 530
bolt
Stud bolt
1.6-2.5 Q235(A3) 35 30CrMoA
4.0-10.0 35 35CrMoA 25Cr2MoVA
16.0-20.0 30CrMoA 35CrMoA 25Cr2MoVA
nut 1.6-2.5 Q235(A3) 30 35
4.0-10.0 30 35 35CrMoA
16.0-20.0 35 35CrMoA

Heat treatment must be carried out when selecting alloy steel materials. When there are special corrosion resistance requirements for fasteners, stainless acid-resistant steels such as Cr17Ni2, 2Cr13, 1Cr18Ni9 can be selected.