Xrciser® Series Partial Stroke Testing Device
Begin with any QTRCO actuator, add tandem pistons to serve as pneumatically engaged travel stops, and controls as appropriate for your application.
Xrciser® Overview
The standard QTRCO actuator uses a travel stop screw in the end cap to limit outward travel of the actuator piston, and therefore valve travel. In the XRCISER® configuration the pneumatically engaged tandem pistons become the outward travel stop. By confirming tandem piston pressure and position; spurious valve travel is prevented during the partial stroke cycle.
Benefits:
No spurious valve travel
Full actuator torque output every cycle - inducing partial stroke test
Full emergency operation capability
Local, remote or fully automated control options
Optional diagnostic data collection
Inherent actuator seal and solenoid valve redundancies
Verification testing of solenoid valves
Unlimited number and frequency of worry free partial stroke test cycles
Reduced operator training
Inadequate Methods
MECHANICAL hard stop devices require a purpose built actuator with integral manually engaged travel stops or add-on type manually engaged stops mounted between actuator and the valve
Benefits
Hard travel stops to prevent spurious over-travel
Full actuator torque output to operate a valve experiencing stiction
Negatives
Requires extensive operator training and detailed procedures for both engagement and disengagement operations
Cannot be immediately disengaged should an emergency shutdown (ESD) occur during partial stroke testing - compromising safety!
AUTOMATED partial stroke testing devices allow local or remote control of the PST by exhausting a portion of the actuator air supply to regulate actuator travel.
Benefits
Reduce operator training requirements
Automated control options
Available diagnostic data collection
Redundancy
Negatives
No hard travel stops
Regulating pressure to the actuator through controlled exhaust, greatly reduces applied actuator torque
Valves experiencing stiction may cause timed out false failures; or spurious over travel and process interruption
Slow release of pressure on larger assemblies greatly extends the stroke time and inhibits rapid ESD closure - compromising safety!
Q Series
Offset cylinders align the piston axis with the pinion gear pitch circle diameter, eliminating the cantilever forces inherent in rack and pinion type actuators. Low friction rollers maintain correct engagement of the stainless steel gearing for absolutely exceptional cycle life.
The reduced friction enables outstanding throttling control as demonstrated in numerous 'typical diaphragm actuator' applications where corrosion or high vibration dictated a better solution
F Series
A unique slotted body concept absorbs 100% of the yoke mechanism's side loading forces leaving the piston rod completely free of bending stresses while allowing termination of the rod at the yoke, and the addition of a weight and force balancing second force module diagonally offset from the first. The balanced weight makes lifting and handling of the actuators safer and easier, while reducing valve neck stress caused by unbalanced scotch yoke actuators. Internally, the balanced forces assure less friction loss and less wear as there is no net force applied to the shaft bushings.
T Series
The T-Series actuator demonstrates how we are committed to making life easier. An OEM of over the road bulk carriers was impressed by the capabilities of our Rack & Gear® actuators and they appreciated our ability to mount to numerous valves simply by selecting the proper adapters and mounting plate.
L Series
Using captured springs and the linear components of our rotary, our L Series Actuators provide a safe, long lasting, low friction, stainless steel substitute for diaphragm types in a smaller package for resistance to corrosion and vibration.
XRCISER®
The standard QTRCO actuator uses a travel stop screw in the end cap to limit outward travel of the actuator piston, and therefore valve travel. In the XRCISER® configuration the pneumatically engaged tandem pistons become the outward travel stop. By confirming tandem piston pressure and position; spurious valve travel is prevented during the partial stroke cycle.
Accessories
A wide range of valve actuator accessories make your valve actuator more useful and versatile.