Amachree,
Kevin's method will work, or you can model weightless rigids with a node at the CG and then input a force (equal to the entire weight of the valve) at the CG node and include F1 in your OPE and SUS load cases. That will give you the weight acting at the CG. The method you outline above will put only half the weight at the CG and the other half split between the two ends of your rigids away from the CG.
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Loren Brown
Director of Technical Support
CADWorx & Analysis Solutions
Intergraph Process, Power, & Marine
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