captain wrote: ↑Thu Oct 24, 2019 10:52 am
If I recall correctly the CFR requires bushing to be removed so the tank threads can be inspected.
You are absolutely correct. For the required visual inspection, it is required to inspect the threads and therefore any adapter bushing has to be removed, during the visual inspection.
But to actually perform the hydro portion of the test you are using the needed fitting or adapter to create a reliable seal with the cylinder. There is no restriction on the type of fitting or adapter.
I actually had a custom adapter machine out of steel to test my European (Poseidon and Drager) metric tapered thread cylinders.
During the hydro test it doesn't matter if there is a bushing or any type of adapter as long as it seals, it can take the pressure, and it doesn't trap any air when the cylinder is being filled with water.
I have work in or with several hydro facilities and the connection fitting from the submerged jacket lid to the cylinder was not always the same, but they all had means to use different adapters with all the required thread connections for different cylinders.