Reflux 819/FO is a pilot-operated gas pressure regulator classified as Fail Open according to the European Standard EN 334.

Its use is strongly recommended in high-pressure transmission systems and in medium pressure natural gas distribution networks. It is suitable for use with previously filtered non-corrosive gases.

Reflux 819/FO is Hydrogen Ready for NG-H₂ blending.

• Accuracy class AC: up to 2.5
• Nominal sizes DN: 1″, 2″, 3″, 4″, 6″, 8″, 10″, 12″
• Lock-up pressure class SG: up to 5
• Design pressure: up to 102 bar
• Design temperature: from -20 °C to +60 °C
• Connections: class 150, 300, 600 RF or RTJ according to ASME B16.5 and PN 16 according to ISO 7005
• Minimum differential pressure: 2 bar when used alone
• Range of downstream pressure Wd: from 1 to 74 bar
• Inlet pressure range bpu: from 3 to 102 bar
• Configurations: Silencer, Slam shut, Monitor