One piece Structure

* No potential body leak path.

* requires use of reduced port ball.

* significant pressure drop.

* Not repairable.

Two-piece

* most common in building services.

* Best price value.

* Available in full or standard port balls.

* Not recommended to be repaired.

Three-piece

* more costly.

* easier to disassemble.

* Can be repaired in pipe line.

* Available in full or standard port balls