Samson 3277 Mounting And Operating Instructions

Also see for 3271: Mounting and operating instructions Mounting and operating instructions Mounting and operating instructions Mounting and operating instructions Manual

EB 8310-5 EN 25Mounting and start-up5. Screw the short nuts (A21) with washers(A25) onto the bolts (A20). Observetightening torques.5.2.2 Increasing the actuatorthrustThe thrust can only be increased in actuatorswith "stem extends" action. To achieve this,the springs of the actuators can be preload-ed by up to 25 % of their travel or benchrange.Example: Preloading is required for a benchrange of 0.2 to 1 bar. 25 % of this span cor-responds to 0.2 bar. Therefore, the signalpressure range is shifted by 0.2 bar to 0.4 to1.2 bar. The new lower signal pressurerange value is 0.4 bar and the new uppersignal pressure range value 1.2 bar.Î Write the new signal pressure range of0.4 to 1.2 bar on the actuator nameplateas the operating range with preloadedsprings.5.2.3 Adapting the travelrangeIn some cases, the valve and actuator havedifferent rated travels. Depending on the di-rection of action, proceed as follows:Direction of action: actuator stem extendsAlways use actuators with preloaded springswhen the valve's rated travel is smaller thanthe rated travel of the actuator.Example: DN 50 valve with 15 mm ratedtravel and 750 cm² actuator with 30 mm rat-ed travel; 0.4 to 2 bar bench range.The signal pressure for half of the actuatortravel (15 mm) is 1.2 bar. Adding it to thelower signal pressure range value of 0.4 barresults in a signal pressure of 1.6 bar re-quired for preloading the springs. The newlower signal range value is 1.6 bar and thenew upper signal range value 2.4 bar.Î Write the new signal pressure range of1.6 to 2.4 bar on the actuator nameplateas the operating range with preloadedsprings.Direction of action: actuator stem retractsThe springs of actuators with "stem retracts"action cannot be preloaded. When aSAMSON valve is combined with an over-sized actuator (e.g. the rated travel of theactuator is larger than the rated travel of thevalve), only the first half of the actuator'sbench range can be used.Example: DN 50 valve with 15 mm ratedtravel and 750 cm² actuator with 30 mm rat-ed travel; 0.2 to 1 bar bench range.At half the valve travel, the operating rangeis between 0.2 and 0.6 bar.