Bolts/Studs and washer location when used on flanges.

[et3752]

Bolts/Studs and washer location when used on flanges. Is there any printed standard or code that defines where the washers are to be installed i.e. for bolts at the nut and not the head and studs on both ends under the nuts?

 

[CoryPad]

Guidelines for Pressure Boundary Bolted Flange Joint Assembly[/I]] Use of washers is optional. However, it is generally recognized that the use of through-hardened steel washers will improve the translation of torque input into residual bolt stretch.