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Sizing & Selection Criteria for Control Valve Actuators

Valves are used to control the flow of fluid in process systems. During routine operations, the position of valves often needs to be opened or closed regularly. In large plants, manually adjusting these valves can be time-consuming and largely impractical.

In these cases, valve actuators are used in place of hand-operated wheels and levers. Valve actuators are mechanical devices used to adjust valve positions. Instead of having operators physically locate and reposition valves, valve positions can be adjusted from a remotely located control room.

The actuator itself is a mechanism that produces a particular motion to control a valve. This motion can be either:

  • Linear

Forward/backward or up/down in a fixed plane (such as in a globe valve)

  • Rotary

Revolving around a fixed axis (similar to butterfly valves)

Valve actuators can be used with control valves to throttle or regulate process flows, or they can be used in isolation valves to stop the flow of fluid at a given location. These devices are commonly used in a variety of industrial plants, including:

  • Water/wastewater treatment facilities
  • Power plants
  • Oil refineries
  • Food and beverage
  • Oil and gas

Types of Valve Actuators

The working principle of actuator valves primarily depends on their driving force. The two most common types of valve actuators are pneumatic and electric.

  • Pneumatic Valve Actuators

Pneumatic valve actuators are the most common type of actuator used in process systems. These actuators use air (or other gas) pressure as a main power source. Air pressure is used to produce motion to control the position of the valve.

For double acting and spring return models, we offer two different styles of rack and pinion pneumatic actuators. Rack and pinion pneumatics are excellent for a variety of industrial applications in fields such as chemical & plastic, food & beverage, and a whole breadth of general industrial sectors.

Our rack and pinion actuators are available in the PN Series or the SS Series with two different body material options (hard anodized extruded aluminum or stainless steel), plus feature ISO and NAMUR mounting to meet international standards.

  • Electric Valve Actuators (Motor Driven Actuators)

Electric actuators use electricity as their primary power source. Electricity is used to produce the motion which opens or closes the valve as required. These types of actuators fall into two general classifications: solenoid actuators or motor driven actuators.

In solenoid actuators, an electric current is applied to a wire coil (solenoid) which produces a magnetic field. This magnetic field pulls on a metal plunger which pushes the valve stem downward. When the solenoid is de-energized, the spring retracts the plunger upwards and reopens the valve.

In motor driven actuators, the valve stem is controlled by an electric motor. A servo amplifier provides a DC signal to the motor which moves the valve stem in a linear motion to the desired position.

 

Valve Actuator Selection Guide

Valve actuators are an essential element in the efficiency of process systems and also play a significant role in process plant safety. It is therefore crucial that the right type of valve is selected for the given environment to ensure optimal valve operation.

The following factors must be taken into consideration when determining the most appropriate type of valve:

  • Power source

One of the first factors to consider is the most effective power source for the actuator. Power source availability, control access, valve size, frequency of operation, and required torque are all factors to consider when choosing between pneumatic or electric actuators. For pneumatic actuators, an air pressure generally between 40 and 120 psi would need to be provided. Most electric actuators would require available access to a 110 AC power supply, although different sized AC and DC motors are available.

  • Temperature range

The operating temperature range for pneumatic actuators is typically between -4° and 174° F (-20° to 80° C). With appropriately rated seals, bearings, and grease, this temperature range may increase to -40° to 250° F (-40° to 121° C). In low temperatures, the dew point in relation to the environmental temperature should be considered, as frozen condensate can affect the ability of the air supply port to provide sufficient air pressure.

Electric motors are typically available in temperature ranges between -40° to 150°F (-40° to 65°C). Special care should be given to electric motors in outdoor applications. The unit should be properly enclosed to prevent the accumulation of condensation and rainwater which can negatively affect the actuator.

  • Hazardous locations

Pneumatic actuators are preferred in areas with hazardous, explosive, or flammable gases, vapor, or dust due to their lack of ignition source. Electric actuators, on the other hand, work with electricity, which is a classified as a source of ignition. Therefore, electric actuators need to be contained in NEMA, UL, or CSA-approved enclosures to prevent ignition of the external environment.

Learn More

BI-TORQ Valve Automation has served countless industrial, commercial, and municipal clients for over 35 years. Since our valve automation department began operations over 23 years ago, we have supplied thousands of butterfly valves, electric and pneumatic actuators, limit switches, and proximity sensors to customers worldwide.

We are proud members of the Valve Manufacturers Association of America (VMA), and our proficient technical team is well-versed in valve actuators of all types. Our 25,000-square-foot manufacturing facilities allow us to operate efficiently to meet even the strictest client requirements without compromising quality or service.

If you would like to know more about our valve actuators, services, or other products, please contact us or request a quote.

Where do Your Valves Go?

“Where do your valves go?” is a frequently asked question for those new to selling and specifying BI-TORQ valve packages. The general answer is anywhere media (liquid or solid) needs to be conveyed or regulated in a piping system, or stored in a tank. That answer helps, but is quite general. We need to narrow that scope down to the industry level and add some sample series that you’ll find there to get a better idea.

If you take a look at the images below you can get a sense of where individual series can be found along with a brief description of each major series.  This is by no means meant to be a catch-all, but it should give a good starting point to think about how our product line can help fill your needs.

Product Series/Industry Matrix
Product-industry matrix

Series SnapshotSeries snapshot

Valve Types: Butterfly Valves and Ball Valves

Valves are used in a wide range of applications to control the flow of slurries, liquids, and gases. Among the most common valves in use today are butterfly valves and ball valves. Each type of valve has its own advantages and disadvantages, but each operates on similar underlying principles.

Butterfly valves are connected to a handle, gear operator, or actuator that turns a shaft connected to a metal disc inside of the valve by 90°. When the disc is turned in the direction of the flow, the valve is fully opened, allowing materials to move past the disc and down the pipe. Conversely, turning the disc so that it’s seated across the flow path will block the flow.

Ball valves are also connected to a handle or actuator that turns a valve shaft, but unlike butterfly valves, they contain a spherical ball with a hole drilled through it in one direction to block or release flow. Turning the drilled half of the ball toward the material releases the flow while turning the solid side of the ball toward the material blocks the flow.

Butterfly Valves: Applications and Advantages

Butterfly valves are most often used to regulate the flow of gases, liquids, or slurries. Because they can be designed with reference to specific pressure requirements and usage patterns, their applications are very broad. Some of the more common include:

  • Water, air, gas cooling
  • Fire protection
  • Food and beverage production
  • Chemical processing
  • Pharmaceutical manufacturing
  • Slurry services
  • Throttling
  • Vacuum services

 

Butterfly valves have a number of advantages over alternative flow management solutions, including:

  • Speed

Butterfly valves open quickly as compared to multi-turn valves. The ability to remotely control them also saves time, since users don’t need to travel to each valve location.

  • Affordability

Butterfly valves are less expensive than most other types of valves due being less material intensive.

  • Size

Because butterfly valve assemblies are smaller than other valves, they are ideal for applications with tight space requirements.

  • Throttle

Butterfly valves are well-suited to applications that require liquids, gases, or slurries to be throttled for sustained periods.

  • Low Maintenance

Butterfly valves tend to require little maintenance, and most have a long service life.

  • Easy installation

Butterfly valves are typically simpler to install than other valves.

  • Leak-proof

The speed of automation combined with the standard tight seal of a butterfly valve essentially eliminates wastage or leaks.

Ball Valves: Applications and Advantage

Ball valves are used in liquid and gas applications that require a tight seal. Like butterfly valves, they can be adapted to a wide variety of purposes. Because they offer increased control, ball valves have become increasingly popular in many industries. Their applications include:

  • Chemical processing
  • Life sciences
  • High-pressure
  • High-temperature
  • Food and beverage production
  • Measurement and control
  • Utilities
  • Water cooling
  • Drains and vents

 

Ball valves offer many advantages over manually operated ball or butterfly valves, including:

  • Speed

Ball valves can be opened and closed more quickly than multi-turn valves. The ability to remotely control them also saves time, since users don’t need to travel to each valve location.

  • Multi-port

Applications that require superior control can benefit from the control offered by multi-port automated ball valves.

  • Long Service Life

Ball valves are designed to withstand the strains of intense industrial applications. To extend product life, many valves also allow for component replacement during maintenance.

  • Simplicity

Automating ball valve control at a single control point simplifies operations and streamlines existing processes.

  • Leak-proof

The speed of automation combined with the standard tight seal of a ball valve essentially eliminates wastage or leaks.

  • Full Flow

With no obstructions in the flow, a ball valve offers higher flow rates than a butterfly valve.

 

The ability to control the flow of fluids or gases from a single control point can significantly improve efficiency throughout your operation. Automating ball valve or butterfly valves in your facility will enable you to optimize your time and streamline your processes, which will ultimately result in a positive impact on your bottom line.

With more than 20 years of experience in providing automated valves, BI-TORQ Valve Automation has the expertise needed to develop the perfect valve and actuator for any application,

Whether you’re searching for a standard catalog product or a customized solution, our technical sales staff stands ready to solve any challenges you might face.

To learn more about butterfly valves, automated ball valves, or our other products and services, please request a quote or contact us.

Product Announcement 01/11/2017

BI-TORQ Valve Automation is now managing the sales efforts of Strahman Valves’ line of piston-type sampling valves. The shift allows our current customer base to have full access to the sampling line under the BI-TORQ banner of products.

The reasoning for the shift was a fairly straightforward one for Strahman Valves. While sampling valves, a type of valve used to take a representative sample or portion of a liquid, gas, or solid for testing purposes are not quarter-turn valves like the rest of BI-TORQ’s portfolio of products, they do fit in nicely with our MRO and PVF distributors who call on chemical, food and beverage, pulp and paper and pharmaceutical accounts daily. The ability to offer automated valves, safety products and now sampling valves will allow our distributors to offer a complete suite of products for plant replacement needs or the next bid for expansion.sv8-d

For those companies that already are dealing with Strahman Valves, the process doesn’t change for quotations or shipments – both will come out of our headquarters in Bethlehem, PA. The advantage you get is access to BI-TORQ’s line of products. We pride ourselves on our ability to provide product to just about any customer with our 5 main categories of products – automated valves, safety products, fire safety thermal shut-off assemblies, retro-fit automation packages and customized mounting hardware.

If you are new to sampling valves, but eager to learn about the applications that can be found at your customers, BI-TORQ will lead the way with help. We can offer our proven style of training and service via webinars, lunch and learns or joint sales calls.

The Strahman Valves sampling line includes three bases series: the QA series – a quick advance ¼ turn type; the SV series – a resilient seated type; and a MS series – a metal seated type. The line also as specific lines for pulp and paper and sanitary applications. Each of the series can customized to suit the needs of the application including, but not limited to piston extensions, heat jackets, materials or construction and end connections.

Gold just isn’t for fall leaves

BI-TORQ was recently specified and has received an order for several thermal shut-off valve assemblies to ship in early November. The valve packages range in size from ½” through 6” and are for a large gold mine in Central Asia.

The carbon steel ANSI 150#  assemblies are going to be installed in a diesel system to offer complete emergency shut-off protection in areas such as the main fuel storage tanks; inlets and outlets of generators; day tanks; the fire pump diesel tank; boiler fuel inlets; and fuel feeds to the mill and screening areas. This approach offers maximum protection with a product of this type.

If you take a look at the image below, you can see how the strategic placement of our thermal shut-off valves maximizes plant safety. This is accomplished 3 major ways. First, it allows for fuel lines to be shut down at critical junctures in the event of a fire. Our assemblies will stop flow into buildings or at branch points to keep flammable media from feeding a fire due to ruptured pipes, broken fittings or other leak points in the system. The thermal shut-off valves will also isolate tanks at their source, keeping the bulk of the flammable material safely in a tank. Additionally, they can also be used on top of tanks in a fail-open configuration as tank vacuum protection. Lastly, they can be used to shut down pumps when a localized fire breaks out. This is done by using the position feedback option to send a signal to the PLC.

FLP Placement - Diesel System

Whether your protection needs are simply for a small day tank in a commercial building or for a comprehensive fuel system at a industrial facility, you can count on our FM approved thermal shut-off valves.

How Reliable is Your EBV?

Emergency block valves are critical in isolating flammable and toxic media, but once installed they can become an afterthought. When the time comes for them to be used, will they perform as expected or will they be frozen in place due to lack of maintenance? If they are operational, are they easy to maintain? The valves may have been installed long ago, so are parts still available? If you answered ‘yes’ to any of those questions, BI-TORQ Valve Automation’s new R-EBV is the answer.

FEATURES

The R-EBV is a field re-settable emergency block valve designed for refineries, chemical plants and other facilities that deal with flammable or toxic media. The R-EBV’s modular design and small foot print make it easy for one person to operate/test and maintain each assembly as part of a quarterly or annual maintenance program.

What really sets the R-EBV apart is its ability to provide automatic closure three ways – localized heat from a fire, a remote electric signal or by push button control. This ensures that no matter what the situation, the R-EBV can shut down a piping system or tank when required.

MAJOR COMPONENTS

The valve portion of the assembly is quarter-turn API 607 fire safe valve. The R-EBV can be supplied as a complete BI-TORQ package with one of our fire safe valves or we can assemble an AML or customer-specified valve to the topworks at our facility.

A declutchable gear override is used in the design for arming and manual operation. A handwheel operator is standard, but other options are available for situations where spatial constraints are a concern.

The stainless steel triggering mechanism and switch linkage enclosure is laid out for easy access and part replacement. The enclosure is fully covered for safety and includes a red indicator to show the unit is armed.

The R-EBV incorporates a hydraulic dashpot to allow the closing speed of the valve to be adjusted to avoid noise, vibration or pipe breakage due to hydraulic shock.

A domed limit switch box with integral solenoid is the most customizable aspect of the R-EBV. The switch portion provided continuous position feedback and visual indication while a signal to the solenoid will trigger the assembly to close. The solenoid also comes with a push button override for periodic testing. The standard switch assembly has a flame proof enclosure, 2 proximity switches, and a stainless steel solenoid valve, but can customized to meet the specifications of an end-user.

Once released by the triggering mechanism, the spring pack provides torque necessary to close the valve. With torques available to 22,000 in.lbs, the R-EBV can fit on large fire safe valves at refineries and power plants. The reliable clockspring design of the spring pack allows for a smooth torque curve, ensuring that when the situation dictates the valve will shut to isolate a tank or piping section.

BI-TORQ’s dependable PN series rack and pinion actuator is used to hold and release the spring pack. The spring return actuator in the design is considerably smaller than what you would find on a purely pneumatic EBV. This allows for a much lower air consumption rate, saving money at the facility.

The air inlet of the pneumatic actuator includes a fusible plug to allow for automatic closure due to ambient heat from a fire. The plugs are available in a variety of temperatures from 165° F through 450° F.

The valve mounting hardware is all stainless steel and engineered to withstand an internal vibration test.

SUMMARY

As demonstrated above, R-EBV’s versatility and customizable components ensure that the units will be the standard in the emergency block valve market for decades to come.

To find out more about this product, including applications and how to specify a R-EBV, please contact Rich Caudillo at rcaudillo@bitorq.com to set up a webinar or to schedule onsite training.

In case you missed our article in Valve World Magazine

In case you missed it, BI-TORQ Valve Automation was the cover story of Valve World’s Control & Smart Valves Special. We were very excited to be able to showcase our capabilities and demonstrate the fact that we are a leader in not only the valve automation and customized mounting hardware industries, but now in the thermal shut-off industry as well.

Take a few minutes to read Valve World’s Sarah Bradley interview with Dave Marut, BI-TORQ Valve Automation’s Vice President of Sales and Marketing.

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If you’d like to learn more about how our thermal shut-off valves work or where you might find opportunities for them, click on the link below. 

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