Matching issues for bolts, nuts, and spherical washers in high-temperature vessels
Thread Content
The design pressure is 4.4 MPa, the design temperature is 475°C; sealing is achieved using wound gaskets. The bolt material is 25Cr2MoVA, while the nut material is 30CrMoA. The spherical gaskets at the two pipe ends are made of different materials: 30CrMoA and 30Mn respectively. What I can’t figure out is which material washer is more suitable for this equipment? Does the design temperature need to be considered for spherical washers? Should we still consider the material compatibility issue between the washer and the nut? I ask all the experts to help answer this and provide evidence.
Washer standard HG/T21573.4