ASME SA193 B8 (304SS)/B8M (316SS)Class 2 (Class II) stainless steel studs and bolts are used in applications where standard (class 1) bolting is not acceptable. Class II bolting goes through a strain hardening process that increases the tensile strength. This has several practical applications:
*Firstly, the strength allows the bolts to service as better options in pipeline applications where the mating flanges are low strength. With the increased use of non-metal piping systems such as fiberglass, PVC, CPVC, PVDF, Poly Pro, etc. etc., low strength flanges are becoming more and more common. Furthermore, these systems typically take gaskets such as EPDM, rubber, or a chemical gaskets. These gaskets often need to compress at a higher torque rating than the gaskets will allow. Class II bolts allow those same flanges to be used with the same gaskets, but because they are stronger, they do not require the flange to be tightened as much. This provides a better seal, and more importantly, prevents a lot of cracked flanges!
*Secondly, the strain hardening often makes a significant issue in galling. Galling is one of most common uses that stainless fasteners are avoided. Strain hardening the bolts or studs can go a long way in making the install process less painful!
We have a lot of experience dealing with Class II bolting, and provide additional solutions for pipe applications, but connecting to the vessels and in the pipeline itself. Please contact us today.