No matter which bolting method you use, mixed ratings in the spec is not a problem since you cannot mix them in any given joint.
In the old system each flange is assigned a particular bolt and bolt length in the pipe spec via the boltref. Isodraft takes 1/2 the bolt length from flange 1 and 1/2 the bolt length from flange 2 plus any wafer items in the joint and adds them together. It then finds the nearest matching length from the NSTD table.
In the new system the flanges are not assigned particular bolts in the pipe spec. Instead it uses the boltsets assigned to the flanges in the catalogue to calculate a length, then adds on the wafer fittings and gaskets. It then finds the highest priority BTYP in the joint and accesses this in the bolt spec for the correct diameter. From here it gets the boltref and then finds the nearest matching length from the relevant LTAB.
The use of the BSEL is to direct Isodraft to a particular bolt when all else is equal. In most projects this does not occur very often, if at all.
No matter which bolting method you use, mixed ratings in the spec is not a problem since you cannot mix them in any given joint.
In the old system each flange is assigned a particular bolt and bolt length in the pipe spec via the boltref. Isodraft takes 1/2 the bolt length from flange 1 and 1/2 the bolt length from flange 2 plus any wafer items in the joint and adds them together. It then finds the nearest matching length from the NSTD table.
In the new system the flanges are not assigned particular bolts in the pipe spec. Instead it uses the boltsets assigned to the flanges in the catalogue to calculate a length, then adds on the wafer fittings and gaskets. It then finds the highest priority BTYP in the joint and accesses this in the bolt spec for the correct diameter. From here it gets the boltref and then finds the nearest matching length from the relevant LTAB.
The use of the BSEL is to direct Isodraft to a particular bolt when all else is equal. In most projects this does not occur very often, if at all.
