VALTEX FLOWSERVE

VALTEX FLOWSERVE FAIL: IN PLACE HEAVY-DUTY LINEAR SPRING CYLINDER ACTUATOR SERIAL NO: 372818.001-2 DATE 2/18/16 MAX AIR PRESSURE: 150 PSI. FLOWSERVE VALTEK VL SERIES HEAVY-DUTY LINEAR SPRING CYLINDER ACTUATOR CONFIGURED WITH A DOUBLE-ACTING PNEUMATIC SYSTEM AND CUSTOM FAIL-SAFE CONTROLS. TECHNICAL SPECIFICATIONS BREAKDOWN: MANUFACTURER: FLOWSERVE VALTEK ACTUATOR TYPE: AIR-TO-CLOTH / AIR-TO-CYLINDER (ATC) DOUBLE-ACTING PNEUMATIC CYLINDER. MODEL/SERIES: VL 100 (LINEAR VL SERIES SIZE 100 CYLINDER FOR HIGH-THRUST PROCESS APPLICATIONS). STROKE LENGTH: 8 INCHES (203 MM) OF LINEAR TRAVEL OPTIMIZED FOR LONGER-STROKE PROCESS CONTROL. FAILURE MODE: FAIL IN PLACE (ALSO KNOWN AS FAIL-LOCKED / LOCK-IN-PLACE. "FAIL IN PLACE" SYSTEM DESIGN: STANDARD VALTEK VL ACTUATORS RELY ON AN INTERNAL MECHANICAL SPRING TO PUSH THE VALVE FULLY OPEN OR CLOSED WHEN AIR SUPPLY IS LOST. BECAUSE YOUR SPECIFICATION REQUIRES THE VALVE TO FAIL IN PLACE THIS STANDARD SPRING RETURN IS BYPASSED OR SUPPLEMENTED USING AN EXTERNAL PNEUMATIC LOCK-UP SYSTEM. TO ACHIEVE THIS YOUR ASSEMBLY WILL TYPICALLY FEATURE: A DOUBLE-ACTING POSITIONER: MODULATES AIR SUPPLY BOTH SIDES OF THE INTERNAL PISTON TO MAINTAIN DYNAMIC POSITIONING ACCURACY. AN EXTERNAL LOCK-UP VALVE: A SPECIALIZED THREE-WAY OR FOUR-WAY PNEUMATIC SWITCHING VALVE INSTALLED DIRECTLY IN THE AIR LINES BETWEEN THE POSITIONER AND THE CYLINDER PORTS. OPERATION: UPON A SUDDEN DROP OR COMPLETE LOSS OF SUPPLY PRESSURE THE LOCK-UP VALVE IMMEDIATELY TRIPS TRAPPING THE EXISTING AIR VOLUME INSIDE BOTH THE TOP AND BOTTOM CHAMBERS OF THE VL 100 CYLINDER. THIS PNEUMATIC TRAP LOCKS THE PISTON EXACTLY WHERE IT IS PREVENTING THE VALVE PLUG FROM MOVING UNTIL AIR PRESSURE IS SAFELY RESTORED.