Bolt Length Calculation for Components with Mixed Bolt Needs

The calculation of bolts through components with mixed bolt needs is the same as the general wafer calculation, but allows for different bolts in the set to start and stop at different places within the joint.

If a wafer component has a BLRF of CATREF, and the BTHK value for a particular bolt is not zero, then the specified thickness is used in the calculation. If the BTYP of the bolt is JACK, TAP or CAP, this will complete that particular bolt. A subsequent BTYP of JACK, TAP or CAP for the same bolt NUMBer further on in the joint triggers a new bolt.

This allows for such a situation as a wafer lug valve, with some bolts going through the whole joint, and some cap screws on either side bolting into the body of the valve (see the Example Data Flow Diagram for a Wafer Lug Valve image in Example Wafer Lug Valve).

Bolts are selected from the Specification as normal, but each bolt path through the joint will be able to start and stop at different points within the joint. A BTYP of NULL indicates that no bolt is required at this particular point in the joint. This is only permitted before the start of a bolt or after the completion of a bolt. If inconsistent combinations of bolt path data are found for a particular bolt, an error message is output, no bolts are output for that joint, but detailing will continue.