Hydraulic piping couplings are built for especially harsh conditions of use. They offer many advantages over the screw couplings standardised to ISO 14541. They can be coupled under pressure without leaks, prevent air from penetrating during the coupling process, prevent loss of media when decoupling and are equipped with less sensitive round threads. The high pressure screw couplings are mainly used with hydraulic tools (e.g. from Power Team). For this reason they are equipped with NPT threads that are also used for hydraulic tools. Both hydraulic coupling types cannot be coupled with each other or with the screw couplings acc. to ISO 14541.