Is the HZ form of the new expansion joint necessary to have a straight edge at the junction of the two halves of the wave?

Does the HZ form of the new expansion joint have to have a straight edge at the junction of the two halves? It's different from the old HF.
2020-05-09 Reply
HF cancelled, HZ is half-wave welding with straight edge
2019-08-01 08:44:46 Reply