Main features: Electric module operator for regulating the gas flow, in steps (836 TANDEM) variable (837 TANDEM). Two low-noise automatic solenoid valves, class B. Servo-controlled pressure unit. Pilot burner outlet. Inlet filter and ignition gas filter. Inlet and outlet pressure gauge connection. Threaded gas inlets and outlets (RP 1/2"), flange connection possible "Air" connection of pressure controller to combustion chamber Technical data: Gas connections: Rp 1/2 ISO 7 Any mounting position. Gas family: I, II und III Highest gas inlet pressure: 60 mbar Ambient temperature: 0...70°C Pressure controller: class C Automatic solenoid valve: class B 836 TANDEM Step modulator - outlet pressure: Highest pressure: 7...50 mbar (version 230 V: 7...37 mbar) Lowest pressure: 2...45 mbar (version 230 V: 2...30 mbar) 837 TANDEM Variable modulator - outlet pressure: 2-20 mbar (white screw)