Samson 44-7 Mounting And Operating Instructions

Also see for 44-4: Mounting and operating instructions

12 EB 2723 ENDesign and principle of operationvalve. Diaphragm failure is indicated by ared mark in the diaphragm rupture indicator(12) (point of response at approx. 1.5 bar)or medium escapes at the test connection.The Type 44-4 Safety Excess Pressure Valveadditionally has a second backup dia-phragm (6.2). Upon failure of the first oper-ating diaphragm (6.1) the regulator is fullyopened. Diaphragm failure is indicated by ared mark in the diaphragm rupture indicator(12) (point of response at approx. 1.5 bar)or medium escapes at the test connection.3 Design and principle of oper-ationÎ Refer to Fig. 3The regulator are closed when relieved ofpressure. They open when the upstreampressure rises above the adjusted set point.The Type 44-4, Type 44-7 and Type 44-8Excess Pressure Valves mainly consist of thevalve (1) with seat (2) and plug (3) as wellas the actuator with operating diaphragm(6.1), set point spring (8) and set point ad-juster (10).The excess pressure valve is used to maintainthe pressure upstream of the regulator to anadjusted set point.The process medium flows through the regu-lator between seat and plug in the directionindicated by the arrow on the body. The po-sition of the valve plug determines the flowrate and, as a result, the upstream pressure.The upstream pressure p1 to be controlled istransmitted over the control line (11) to theoperating diaphragm (6.1) where it is con-verted into a positioning force. This force isused to move the valve plug according to theforce of the set point spring (8). The springforce can be adjusted at the set point adjust-er (10).The Type 44-8 Safety Excess Pressure Valveadditionally has a second backup dia-phragm (6.2). Upon failure of the first oper-ating diaphragm (6.1) the regulator contin-ues to function using the backup dia-phragm (6.2). In this case, the regulatorfunctions as a safety valve when the up-stream pressure rises too far and opens the1 Valve body1.1 Stopper1.2 Seal1.3 Seal2 Seat3 Plug with plug seal3.1 Balancing piston3.2 Plug nut3.3 Plug stem3.4 Plug spring3.5 Plug nipple3.6 Guide nipple4 Coupling nut5 Inspection bore6 Actuator housing6.1 Operating diaphragm6.2 Backup diaphragm7 Diaphragm stem8 Set point spring(s)9 Spring plate10 Set point adjuster11 Control line12 Diaphragm rupture indicator13 Body screws14 Distance ring15 Diaphragm plate nut16 Diaphragm plate17 O-rings