To assist designers in the proper selection of Lee Plugs, a "proof pressure" is given for up to three hole tolerances (Classes I, II, III). The Lee Plug proof pressure is the highest hydrostatic pressure that may be applied in the course of routine Production Acceptance testing.
The Lee Plug proof pressure values stated in this website are defined for Lee Plugs when installed into boss materials identical to that of the Plug. When installing Lee Plugs into dissimilar materials, please contact The Lee Company for proof pressure recommendations.
Lee Plugs should be selected conservatively. This will provide an additional safety margin for chance situations where the installation process might fail to meet specification or where pressure transients or other factors are unexpectedly severe. As a general guideline, we recommend the Proof Pressure of the Lee Plug chosen exceed the Burst Pressure of the system. Note: Aluminum Plugs not recommended for use above 275°F.