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  • Bob Abramczyk

Key Factors to Consider When Automating Manual Quarter-Turn Valves

a collection of manual turn valves

There are many potential benefits of taking the next step in your industrial fluid process by automating manual valves. These benefits are varied, based on the industrial processes involved and how complex the automation is. When considering process automation, common benefits include:

  • Increased Workplace Safety

  • Increased Productivity

  • Enhanced Product Quality

  • Reduced Manufacturing Lead Time

  • Reduced Labor Cost

  • Reduced Manual Tasks and Medical Costs

Once you decide to invest in valve automation, the sizes and styles of your targeted valves, along with the nature of the application media and installation environment, all play a critical role in choosing which type of valve actuator to standardize. The two primary types of valves (and valve actuators) are quarter-turn and multi-turn. Multi-turn valves include gate valves, globe valves, knife gate valves, sluice gates, and others. Quarter-turn valves include ball valves, butterfly valves, and plug valves, all three having numerous varieties of each.

In addition to the types described above, the motive used to power the actuators (e.g., pneumatic, electric, hydraulic, or even steam) is also a consideration, based on area classification, process cleanliness, available utilities, and the cost to install and maintain them. For this blog, we will concentrate and expound on the pneumatic quarter-turn rack and pinion actuator technology.

How Do I Choose an Actuator?

What considerations are needed to "turn" these....

a collection of actuators

Into these....

various valves

Source: Max-Air Technology, Delta-T Products, and Sesto Valves

Understanding what we are actuating assists our decision in choosing which actuator to use. So, this leads us back to the quarter-turn valves mentioned above, like ball valves and butterfly valves. There are several criteria to consider when approaching the available complexity of these quarter-turn valves, detailed in-depth below.

How Does the “Top Works," or Mounting Interface, of My Valve Connect With the Actuator?

The Top Works refers to the shape of the stem (e.g., square, “double-D,” keyed-round, or splined), the dimensions of the stem, and the mounting holes machined around it into the flat mounting surface. Most modern valve manufacturers standardize on the ISO 5211 mounting interface for their Top Works, expressly for simple and interchangeable mounting onto various actuators of all types, as shown in all the manual valve photos above and drawing below. 

diagram of a quarter-turn valve

Source: Max-Air Technology, Delta-T Products, and Sesto Valves

As an aside, many valve manufacturers also need to utilize a mounting bracket, stem coupler, and additional hardware to mate their valve stem to the actuator’s output shaft. These extra components can add to the cost and physical size of the valve assembly while not always adding value. A few manufacturers design their valves’ Top Works to allow for direct mounting their valves and actuators together, eliminating the need for these costly brackets and couplers.

How Do I Attach Additional Accessories to Complete My Actuator Assembly, Like Limit Switches, Solenoid Valves, and Positioners?

Most modern accessory manufacturers standardize on NAMUR mounting brackets and bolt patterns, used for mounting limit switches and positioners on top of various actuators, and for mounting solenoid valves on the sides of various actuators, as shown below:

accessory mounts

Source: Max-Air Technology, Delta-T Products, and Sesto Valves

I Have Many Different Sizes and Types of Valves—How Do I Size the Actuators to Fit All of Them?

A broad range of actuator sizes to choose from is paramount in matching your required sizing torques to the available actuator torques, which allows you to reduce or eliminate unnecessary actuator oversizing. This ensures you can utilize an actuator of “just the right size” without having to upsize to something too large. In turn, this choice saves the user not only space and weight but eliminates unnecessary actuator costs, as well as the utility costs, to run them.

As an aside, the factors typically used in sizing actuators for a particular valve are:

  • Determining the preferred “Fail Position” of the valve (e.g., Fail-Open, Fail-Close, or Fail-in-Place) if there is an interruption in the air supply, electric power supply or control signal, or any combination

  • This will drive the decision for the actuator to be Spring-Return or Double-Acting

  • The Valve’s Maximum Seating Torque (typically measured in lb-in)

  • The installation areas’ “consistently-available” air supply pressure (typically 60 or 80psig)

  • Any preferred engineering/safety factor, based on process media or other service conditions (e.g., dry service or abrasive media significantly increases a valve’s seating torque)

Different Types of Valves Need to Rotate Through and Stop at Different Angles. How Do I Ensure the Actuator Will Allow Me to Adjust It to Each Valve’s Specific Required Open and Close Travel?

Most actuator manufacturers allow for some amount of angular adjustment at each end of its 90-degree travel, typically +/- 3 degrees at each end. However, the best manufacturers have much longer adjustment ranges of up to +/- 10 degrees on each end, providing unparalleled flexibility when accommodating a broad selection of valve sizes and types.

How Do I Choose an Actuator Manufacturer?

There are still additional criteria to consider when aligning oneself with an actuator manufacturer. Many companies private-label another manufacturer’s actuator for their use. Others produce their own but do so with a limited offering of sizes and only provide a status quo of features and quality. 

There are only a few actuator manufacturers that offer the best of everything mentioned above and then take it to the next level by also differentiating themselves with a unique list of advantages.

Max-Air Technology’s MT Series of rack and pinion pneumatic actuators is a world-leading product line in automation that continues their tradition of Easy Integration, Flexible Customization, and Reliable Performance. Here are several more valued advantages that Max-Air Technology brings to the user:

1. 17 Different Actuator Sizes Available: 50% more sizes than most competitors, reducing “oversizing”

various actuators of many different sizes

Source: Max-Air Technology, Delta-T Products, and Sesto Valves

2. Patented Dual Travel Stops: Standard +/- 10° adjustment open and close; standard 90-degree travel adjustable—down to 70° and up to 110° rotation

inside of a quarter-turn valve

degrees of turns chart

Source: Max-Air Technology, Delta-T Products, and Sesto Valves

3. Precision Honed Actuator Bore: High-end feature, not industry standard; precision bore is more uniform in diameter, concentricity, and parallelism; micro-scratches “hold” factory grease and provide even lubrication and minimize “wiping” effect from piston seals

honing surface finish and microscopic surface grooves comparison

Source: Max-Air Technology, Delta-T Products, and Sesto Valves

4. Exclusive LockMesh® Special Coating: Max-Air’s LockMesh™ Stainless Steel + PTFE coating greatly enhances the aluminum actuator body’s corrosion resistance and is FDA approved for food contact.

close-up of the lockmesh special coating

5. Unlimited Cycle Life Warranty: Max-Air Technology’s MT Series has the Best Warranty in the Industry, made possible by the high cycle life design, which is tested and verified to 1,000,000+ cycles under full rated load.

Estabrook is proud of our storied and successful 55-year history of service and distribution of high-quality industrial equipment to our valued family of customers. We serve our customers with a sense of urgency and integrity, driven by our philosophy of “Total System Solutions.” Our “Five Pillars” approach to tackling our customers’ most complex process needs supports this concept—using Pumps, Valves, Sealing Devices, Service & Repair, and System Controls. 

We look forward to working with your team to better understand how we may be of service to you!

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Estabrook has been a quality provider of Industrial Fluid Handling Solutions for over 55 years. To learn more about our broad range of Industrial applications and pump solutions that we can provide to your organization, please click on the Contact Us Now link:


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