Guidelines
- Bolting for PTFE lined equipment should be new, clean, lightly lubricated and tightened in sequence to manufacturers recommend torques.
- Although these can be exceeded by 50%, over-torquing is not usually the solution to a leaking joint.
Tools and materials
- Stud bolts are preferable to machine screws as excess thread can be evened across the joint.
- It is always recommended to use two washers to ensure that torque readings are true.
Threading standards
- The standard threads for ASME B16.5 are UNC.
- Several components have tapped holes because of their configuration and as standard these have UNC threads. We can also offer metric threads if required.
Cold flow
- All bolts must be retorqued a minimum of 24 hours after commissioning or following the initial full process cycle.
- The torque of all bolted joints should then be rechecked at least annually.