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Industrial Valve Assemblies Using ROTEX Actuators

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ROTEX Controls manufactures high quality pneumatic valve actuators, limit switches and solenoid valves used on industrial valves and dampers.

This video demonstrates some of the ways ROTEX actuators are mounted and assembled to valves along with limit switches and solenoids.

For more information, contact:
ROTEX USA
(888) 813 - 9772
www.rotexcontrolsusa.com

Features of the ROTEX DRS Scotch Yoke Actuator

Actuator Modules

ROTEX actuator spring modules and pneumatic modules can be removed, swapped, rebuilt, or reinstalled on the frame module without disassembling the frame module. No need even to remove top cover of frame module, because all bolting for removal of the modules is external.
Actuators can easily be changed in the field from fail close to fail open by just swapping the positions of the spring and pneumatic modules. No need to dismantle the frame cover or cylinder assembly.
Actuators can be modified from double acting to spring return easily in the field by adding a spring module.

Springs are lifetime lubricated and epoxy coated.

Springs are pre-compressed inside their welded spring modules for safety and ease of use.
Pneumatic cylinders are lined with hard chrome plating. Smooth to eliminate wear of piston seals, the surface is very hard, for long life.
Inside the pneumatic module, dual oversized tie rods are protected from external corrosion. Where the tie rods pass through the piston head, ROTEX has improved the design by providing a slide bearing, where most designs don’t. This bearing is important to help maintain alignment and assure smooth operation.

Frame Module

Inside the frame module, the yoke is supported by life time lubricated bearings. Needle roller bearings ensure the most efficient torque transmission.
Extra heavy duty travel adjustment bolts allow for +/- 10% adjustment of the 90 degree stroke. The area of contact is large, to withstand the impact forces.
The yoke thrust pin is made of case hardened steel to resist wear.
The piston shaft is supported on each side of the frame module by solid bearings that ensure proper alignment and smooth operation.

Flexijoint

Each piston shaft of the ROTEX DRS is equipped with two Flexijoints. These specially designed joints compensate for movement and changes in alignment to reduce internal stresses and increase output torque.
The thrust transmitted through the Flexijoints ensures no side thrust on the cylinder walls and bearings.

Unique Sealing Features

Piston seal is ROTEX X design. Flexibility of the sealing material reduces friction, prevents leakage, and extends actuator life. The X shaped seal is wear compensating, and the unique shape of the seal retains the grease for longer periods. The piston is guided by a PTFE thrust bearing, which helps keep the piston centered, and seal wear to a minimum.
The tie rod seal is also of the ROTEX X design. Old fashioned O-rings are replaced by these flexible, low friction, resilient seals to reduce the failure rate of tie rod seals. Also reduces the wear and tear to the tie rods themselves.
ROTEX has also replaced the standard O-ring of the shaft seal. In this position, we provide a proven V-seal design. This self-energized, wear compensating seal guarantees low hysteresis and minimum friction. Like the X seal of the piston and tie rod seals, the inherent shape of the V-seal helps keep the grease where it needs to be.

Optional Hydraulic Override

ROTEX DRS actuators may be ordered with an optional hydraulic override, or the override may be retrofitted to an existing actuator.
The override is fitted into the spring cartridge, to keep the overall dimensions of the actuator and override to a minimum. Can withstand up to 2,000 psi hydraulic pressure.
Easy to operate.
Special Z seal ensures zero leakage and extended life.

ROTEX Pneumatic Valve Actuator Introduction

Here is a movie/slideshow introducing the ROTEX family of pneumatic valve actuators. The movie includes the ECV "Infinity line of rack and pinion actuators, the DRS scotch yoke series and the DRC and DRV large scale rack and pinion series.

Unique design and high performance features are explained and pictures of automated valve packages are included.

Valve Actuation 101: Comparative Review of Pneumatic Actuators and Advantages of Rack and Pinion

Here's is a good presentation on the various types of industrial pneumatic valve actuators, such as scotch yoke, vane, diaphragm and rack and pinion, and their respective advantages and disadvantages.

ROTEX Controls USA: Valve Automation 101 from ROTEX Controls USA

Industrial Pneumatic Valve Actuator Slideshow

Good slideshow showing design features and capabilities of ROTEX Controls industrial pneumatic actuators and controls.

ROTEX Controls USA - Rack & Pinion and Scotch Yoke Actuators from ROTEX Controls USA

Watch a Pneumatic Scotch Yoke Actuator with Hydraulic Manual Override in Action

An interesting demonstration of a ROTEX DRS high performance scotch yoke pneumatic actuator mounted on a large ball valve. Video shows actuator opening valve, closing valve, the valve position indicator, the hydraulic manual override and manual hydraulic pump. Good visual education for those who never saw a large valve and a large actuator.

16" & 10 " Triple Off-set Valves automated block valves. These are pneumatically operated valves with ASME air tanks for fail close operation on loss of electrical signal. Also included are manual hydraulic over-ride cylinders and spring loaded 3-way diverter valves with "fusible links.

After installation of valve in to pipe line, plant air is supplied to the tank inlet valve. A pipe from the tank outlet to the actuator with filter and regulator provides the actuator clean, regulated supply air.

All electrical connections for limit switch and solenoid valves are terminated in the limit switch housing.

Valve are supplied with small 3-way ball valves with fire-safe "fusible" links and spring loaded handles that will close the valve in the event of a fire.

The manual hydraulic over-ride is used in case of loss of air, or loss of electric. 6 foot and 15 foot hydraulic lines are used to supply the hydraulic cylinders power and must be connected of the valves will not function.

As designed, these valves open in under 5 seconds and close in 1.6 seconds, have the ability to be manually over ridden in the event of a loss of air or electric, and have fire-safe spring loaded links to close the valve in the event of a fire.

Defining a "Quick Acting" Pneumatic Actuator

The desired speed of the pneumatic actuator opening or closing is a consideration of the application itself. For applications where an open valve may feed a fire, or overfill a tank, quick closing is required. Conversely, there are times when lines or tanks need to vented very quickly, or processes must be diverted quickly, and a fast opening actuator is applied.

Pneumatic Actuators can vary in opening and closing speed, depending on air supply, venting orifice, and/or size spring involved. A very general statement of valve actuator opening/closing times is normally in the "tens of seconds" whereas fast acting actuators open or close typically in less than 5 seconds.

The engineering of quick acting actuators must be done by seasoned professionals who fully understand the process. Other considerations when applying fast acting actuators are redundancy, failure mode (loss of energy supply), media, criticality and size.

Picture courtesy of Rencor Controls.

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