Fire hydrant types with illustration of threading

This is the sample from another supplier with the wrong kind of threading. Everything else save for the thread is of an accpetable standard, verified by the firestation guys.

The flange made to accomodate different kinds of tables. But the standard one required is Table D

The wrong threading

An old hydrant recently dug up which is of the required standard. The threading there is the correct type. I think it's the one you said is the London V thread.

The "stem cap" closes clockwise, the threads tighten clockwise.

The correct 3'' flange table D

The correct type of threading