It is closed by turning the locking ring on the triangular part of the opposed DSP coupling.
Extra closure can be applied by locking the connection with couplings wrench.
However, there are differences to the preformed serration on the locking ring and the design of the lugs.
The locking ring of DSP couplings can be turned up to 45°.
[4] Typical materials for the coupling are aluminum, brass and bronze.