BigPatents India

A stop-check valve comprising a body and bonnet containing the flow medium; a disc-plug travelling linearly for opening and closing the fluid passage in the valve in the extreme positions of the disc-plug; a stem, when lifted, allowing the disc-plug to move freely linearly, said disc-plug having at least one through-hole connecting the high pressure zone above the disc-plug to the downstream side, so that the pressure in the high pressure zone is reduced and balanced with the downstream side pressure. Whereby when there is a flow pressure on the upstream side of the flow passage, the disc-plug moves freely toe allow the fluid to pass.