The PTV1 series is said to be interchangeable with the Parker / Tema T series. It is available in the same sizes as the PTV1 and the performance is the same as well; the only difference is the decompression valve, which allows the connection under residual pressure with one of the two sides. The advantage of these couplings is to have some internal valves designed for a greater flow passage than standard couplings. The female half-coupling is equipped with a locking counter nut in order to prevent accidental disconnections. Moreover, DNP says the Zink-Nickel galvanisation of the surface of these carbon steel couplings guarantees excellent resistance to atmospheric agents. PVC caps and plugs are available as well on request.