Actuator Frequently Asked Questions (FAQs)
We are often asked: What makes our actuators different? What is a Flat Yoke? or How does a Rack and Gear Actuator differ from a Rack and Pinion actuator? Also customers that are not as familiar with QTRCO are curious how we achieve such quick cycle times, and how do I change the fail position. So we have compiled a list of questions that are frequently asked.
How is a Rack & Gear actuator different from a Rack & Pinion actuator?
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.
How is a Flat Yoke actuator different from a Scotch Yoke actuator?
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.
What is Amalga or Black Amalgon?
Constructed of fiber reinforced thermoset epoxy matrix, Black Amalgon is a light weight, high strength, corrosion resistant composite material. Approximately ¼ the weight of steel or brass and ¾ the weight of aluminum, BA is much easier to handle than traditional steel tubing. Assembly and maintenance times are reduced and stress loads on connected parts are decreased.
Superior Corrosion Resistance Trouble-free performance in chemical, high moisture and other adverse environments including salt and chlorinated water which results in significant life cycle costs. BA’s manufacturing process ensures a smooth self-lubricating inside surface that prevents pistons from sticking, even after they have remained idle for months. Ongoing tests conducted on non-lubricated cylinders resulted in cycles of greater than a million strokes without requiring seal replacement.
Unlike metals, the product does not dent. Material impact strength is 40 Izod ft.-lbs.
With a very low coefficient of thermal expansion, BA operates efficiently up to 275° F and customers have reported success in using the product at temperatures below -300° F.
This non-magnetic material permits magnetic sensors to control piston movement directly through the wall thickness.
Why are QTRCO actuators a better choice for control applications than traditional quarter turn actuators?
QTRCO Rack & Gear™ Actuators have extremely low internal friction, consume minimal air volume, are able to handle the most severe vibration and are available in stainless steel for complete protection against corrosion. Rack & Gear™ actuators provide throttling capabilities consistent with those of diaphragm actuators with a high level of reliability.
The QTRCO Rack & Gear™ thru-shaft design results in substantial space savings. These actuators have been proven to be excellent companions to quarter turn control valves including those with extended stems. Our revolutionary “Close Mount” design reduces the size, weight and cost of the assembly by passing the valve stem through the actuator shaft with no valve modifications.
How is QTRCO able to achieve such fast stroking speed when others cannot?
Unlike most actuators on the market, QTRCO actuators apply pressure directly to the pistons without internal passages that cause speed restrictions to the air flow into and out of the actuator. This approach allows the actuator pressure ports to be increased to suit the users speed requirements. This feature is available on all actuator sizes and types (DA, SR – fail closed or fail open)
Why are QTRCO actuators safer than other actuators?
We feel strongly that our actuators shouldn’t cause injury to anyone. Thus, we have made safety an integral part of our actuator design, specifically the springs, which can cause serious harm to personnel or damage other equipment if not captured. All QTRCO springs are captured and contained within the force module even if the end cap and cylinder are removed.
How does the XRCISER PSTD work?
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.
Why do QTRCO actuators claim to have the lowest total cost of ownership?
Due to our belief that actuators should not fail - all QTRCO actuators feature robust designs and premium materials. Throughout our history, user’s need for replacement parts has been practically non-existent. The unique simplicity and reduced friction of our designs see to this, and our warranty is a testament to the commitment we have to our customers.
How is the QTRCO performance warranty different from most actuator manufacturer’s warranties?
QTRCO will during the period of 3 years from the date of original invoice, repair or replace (at QTRCO’s sole option) any QTRCO actuator that fails in service regardless of the number of cycles, provided always that the actuator was installed correctly, properly maintained/serviced and applied as per the original user application specifications. The actuator must be returned to QTRCO within the 3 year warranty period at the sender’s cost. The warranty does not apply to any freight or other charges.
How difficult is it to change the fail position in the field?
Both sides of the Q Series and F Series actuators are identical in all aspects. Unlike other actuators that require disassembly for action reversal, QTRCO actuators require only that you remove the top hat and turn them top side down. Q-Series actuators have a female double-square drive and the F-Series have two key ways located 90-degrees apart to readily accommodate action reversal.
Can I replace the individual actuator springs for higher or lower pneumatic supply pressures?
QTRCO actuator spring cartridges are provided in a captured state for your safety. These spring cartridges are assembled at our factory using specially designed equipment, with no intent on being disassembled and replaced in the field. QTRCO does offer complete spring cartridges that are field replaceable and safe for handling and installation by the user. Or as another option, the actuator may be returned back to QTRCO and we will change out the springs as required.
Where can I purchase a QTRCO acutator?
You can purchase a QTRCO actuator directly from QTRCO! Many of our customers ask if they need to purchase our actuators through a distributor, but we make it easy to buy direct!