Product Overview | Diaphragm Air Motors
Bulletin 1600-P Page 3
TOP-LOADING, DIRECT-ACTING Air pressure from the control instrument (indicated as dark gray in the above schematic drawing) is exerted between the two lower diaphragms. Because of the difference in diaphragm areas, the resultant force is exerted in an upward direction. In a balanced condition, the pneumatic force on the diaphragm assembly-plus the upward force exerted by the range spring-will be balanced by the downward force of the zero-adjustment spring. When control-instrument pressure increases, the diaphragm assembly will move upward and the pilot valve will be moved upward; closing the exhaust port and opening the supply port to admit supply air directly to the actuator. The supply air will drive the actuator downward. As the actuator moves down, the range spring will relax until its force decreases enough to offset the increase in control- instrument pressure.
Zero adjustment
Suppression spring
Pilot valve
Supply air
Atmospheric vent
Control-instrument air pressure
Exhaust
Valve-actuating pressure
Diaphragms
Range spring
Supply pressure Control-adjustment air pressure Valve-actuating pres sure
WARNING: Situations dangerous to personnel and property may exist with the operation and maintenance of any combustion equipment. The presence of fuels, oxidants, hot and cold combustion products, hot surfaces, electrical power in control and ignition circuits, etc., are inherent with any combustion application. Components in combustion systems may exceed 160°F (71°C) surface temperatures and present hot surface contact hazard. Fives North American Combustion, Inc. suggests the use of combustion systems that are in compliance with all Safety Codes, Standards, Regulations and Directives; and care in operation.
CONTACT fna.sales@fivesgroup.com T +1 800 626 3477 - F +1 216 373 4237
Fives North American Combustion, Inc. 4455 East 71st Street - Cleveland, OH 44105 - USA www.fivesgroup.com
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