Our manufactured minimum pressure vessels can be installed directly downstream from the air-oil separator. These provides two functions: •At start-up, the value stays closed to a preset level and then opens to maintain a minimum pressure in the air-oil separator. This assures pressure for lubricating the compressor, reduces oil foaming and protects the air-oil separator element. •At shutdown, the check valve closes to prevent back flow through the compressor. Specifications •Flow passages designed for low pressure drop •Aluminum housings •Pressures to 35 kg/ cm2 •Flows to 1500 cfm •Inlet and outlet side ports for pressure taps •2' to 3' NPT or BSP & Plunge Type •Screw compressor valve using - 500 hp •Flow Rate 1500 cfm •Working Pressure 35 kg/cm2 •Working Temperature 110°C •Type Thread type & Plunge •Sizes from 1' to 3' •Materials Cast iron & aluminum.