High pressure couplings can be connected by hand

Edited by the Engineeringtalk editorial team Sep 11, 2001

Holmbury have just released their new range of ISO 'A' connect under pressure hydraulic couplings. The PC couplings, probe and carrier are only available in the 1/2in size.

Holmbury have just released their new range of ISO 'A' connect under pressure hydraulic couplings.

The PC couplings, probe and carrier are only available in the 1/2in size which is most popular on agricultural machinery and associated products.

The couplings are rated to 250 bar maximum working pressure and can be connected, by hand, with up to this residual pressure trapped in the hydraulic supply lines.

Residual pressure can be either be caused by attachments being left out in strong sunlight causing thermal expansion of the oil or machinery being disconnected without de-pressurising the system.

Holmbury have achieved connection under pressure by building relief valves into the body of the coupling halves without reducing the flow path of the oil.

In practice this does not effect the performance of the couplings regarding flow but overcomes a very common problem of not being able to connect hydraulic lines without damaging the coupling and spilling oil to atmosphere.