Are the flange bolts checked during the hydrostatic test? Why?
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Are the flange bolts checked during the hydrostatic test? Why?
The bolts selected according to the design do not require verification
The hydrostatic test wasn’t specifically checked; it’s necessary to take that into consideration when making a choice
Generally, very conservative choices are made; according to the standard matching rules, no verification is usually required.
Generally, no verification is done, and bolts of the specified model are chosen based on the standard requirements.
The safety factor of fasteners is higher than that of the housing, so no calculation is required
It seems that Ding Bomin, Mr. Ding, once raised this doubt, believing that verification was necessary.
In the ASME standards, in NB6000 of Volume III, it is stated that hydraulic testing does not take fasteners into account. Additionally, the fasteners are replaceable, so conducting a hydrostatic test is of little significance. It doesn’t make logical sense.
During hydrotesting, the bolts used for flanges are generally of two types. One type involves flanges that are selected according to standards; in such cases, the bolt material and specifications can be chosen directly based on those standards, and procurement is carried out in accordance with them without any need for further verification. This represents a mature design approach； For non-standard cases, the design or process department, after verification, puts forward requirements regarding materials, specifications, standards, etc.
Fasteners are selected according to standards and generally no verification is performed.
The safety factor of fasteners is higher than that of the housing. So there is a large margin