EPR-Series actuators feature a compact Rack & Pinion and modern Scotch Yoke mechanisms.The extruded aluminum body incorporates an advanced,hard anodizing treatment on the internal and optional surfaces and the body can also be provided in a number of optional finishes including PTFE coted,electroless nickel plated,and a variety of polyester [ower coated colors for udrability increase and corrosion protection.
01_Hard Anodized Body
The extruded aluminum body incorporates an advanced, hard anodizing treatment on theinternal and external surfaces. This provides reduced friction, increased durability andcorrosion protection. The body can also be provided in a number of optional finishes includingPTFE coated, electroless nickel plated and a variety of polyester powder coated colors.
02_Large Piston Design
R-type actuators are designed with an optimally sized piston rack. This minimizes backlashbetween the rack and pinion ensuring that they are precisely engaged. This featureguarantees excellent power delivery and accurate valve modulation.
03_Advanced Rack and Pinion Design
A compact, rugged construction, with dual rack andpinion, guarantees stable torque output throughout theactuator’s travel. The design is also suitable for highcycle, high-speed duties.
R-type actuators provide two external travel stopsallowing for 5adjustment in both open and closedpositions. This allows accurate valve alignment andprovides actuator travel adjustment from 80to 100.Optional bolts fitted to the end caps can provideadditional travel adjustment, for the open position. Theexternally adjusted bolts can provide open positiontravel from 0to 100.
05_Piston Guide Plate
A permanently lubricated, replaceable guide plate is fitted to the piston rack toalosorb lateral defiection and ensure smooth operation by eliminating metal tometal contact, improving wear resistance and increasing efficiency.
06_Drive Shaft Bearings
R-type actuators have self-lubricating, replaceable shaft bearings providing low-friction, andhigh cycle life and reliable performance.
Polyester powder coated end caps provide excellent anti-corrosionproperties, and optional finishes are available, including PTFEcoating, electroless nickel plating or hard anodizing.
08_Blow-Out Proof Drive Shaft
The pinion is fitted with an octagon shaped anti-blow out devicecombined with an oxy-nitriding plated blowout proof bearing, toprovide safe, high cycle life. An electroless nickel is optionallyavailable according to customer’s requirement.
09_NAMUR Standard Interfaces
For ancillary equipment such as positioners and switchboxes, thelatest VID/VDE 3845 mounting interface is provided to allow quick andsimple mounting with direct pinion drive. A NAMUR solenoid mountingpad allows direct mounting of solenoid valves to the actuator.
10_ISO 5211 Valve Interface
The R-type actuator has valve mounting pads in accordance withISO5211 standard, providing standardized mounting for ISOcompatible quarter-turn valves.
11_Visual Position Indicator
R-type actuators are supplied as standard with a visual positionindicator.
12_Simple to Convert
Converting from double acting to spring return configuration issimple and performed by removing the end caps and adding theunique spring cartridges. Actuator rotation is field reversible bysimply removing, rotating by 180and re-installing the pistons.
Double Acting Configuration
As standard the actuator is supplied for counterclockwise rotation whenpressure is applied to port A. This pressurizes the internal chamberdriving the pistons apart. When air is applied to port B the end chambersare pressurized driving the pistons together causing clockwise actuatorrotation. If required, the pistons can be inverted in the housing resultingin clockwise rotation when pressure is applied to port A.
Spring Return Configuration
As standard the actuator is supplied for clockwise rotation in airfailure mode. When port A is vented the springs drive the pistonstogether, causing clockwise rotation. When pressure is applied to portA the internal chamber is pressurized driving the pistons apart andcompressing the springs, causing anti-clockwise actuator rotation.Port B is used as a breather for the spring chamber swept volume.
The R-type actuator is designed such that torque is independent ofactuator travel and is constant throughout the travel range.
Spring return actuators have both spring and air torques and eachtorque has a higher start figure than the end figure. Then R-typeactuator is designed such that the spring and air start torques areequal, as are the spring and air end torques.