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What is Optimization and what can it do for you?

Optimization is the process of engineering the equipment to make it very efficient in its operation.

Optimization

  1. Reduces Hardware cost
  2. Reduces Energy cost
  3. Increases service life
  4. Reduces Total Cost of Ownership

Heaton can optimize your valve actuation needs to achieve the above easily and efficiently. Heaton research and development team possesses the in-depth knowledge that is required to optimize your actuation needs. Start reducing Global Warming by optimizing all your plant processes.

Optimization of Valve Actuation

Valves that are actuated either by pneumatic, hydraulic, or electric operators will always consume energy. However this energy consumption can be reduced tremendously when careful considerations on the sizing and selection are taken.

So to optimize an actuated valve package, it is simply sizing and selecting the most efficient actuator to do the job. But first, valve torques must be determined correctly.

Read further to understand how valve torques are determined correctly.

Break to Open Torque

Break To Open or BTO torque is the torque to start opening the valve against the inlet pressure.

The BTO valve torque at full shutoff pressure with the downstream pressure at atmospheric is the highest torque throughout its entire stroke ( note that this is not true for different valve types ). This torque is a result of the pressure acting on the ball / seat / bearings, which increases the frictional forces, hence the higher the pressure, the higher the torque required to overcome the frictional forces.

Many manufacturers verify their torque calculations by testing the valve with pressurized water.

Break to Open Torque: Common Mistakes made

The BTO torque is also affected by the flowing media. For any lubricating media, the torque measurements taken in the water test would be good for use. However for non-lubricating fluids like Benzene or steam for example, the valve torque will increase simply because the coefficient of friction has now increased. This torque could increase in a range of 22% to 53% with small sizes being affected on a larger percentage than a larger valve. So an actuator selected based on the torque measured under pressurized water will not work in such non-lubricating service, resulting in valves in partially open positions, ultimately destroying the valve seats. The BTO torque is also affected by the valve seat and stem packing material. The coefficients of friction of different materials vary, hence the resultant torque too.

For example, PTFE seats have a lower coefficient of friction than Devlon. A valve with PTFE seats will have a lower torque compared with Devlon seats. Again, if the torque of a PTFE seated valve was used for a valve with Devlon seats, the actuator selected may not work in service if the safety factor used is insufficient.

Run to Open Torque

Run To Open or RTO torque, is the torque to stroke the valve before its fully open position after the valve has started to open.

Similar to the BTO torque, the RTO torque is affected by flowing media and seat / packing materials, and by the flowing pressure drop through the valve.

A common assumption is that RTO torque is the same throughout the stroke of the valve. This is not true unless the flowing pressure drop (the difference between the upstream and downstream pressure) is constant. Higher flowing pressure drops will cause higher valve RTO torques and this has to be considered during all sizing calculations.

Run to Open Torque: Common Mistakes made

Many manufacturers simply use a percentage of BTO torque as the RTO torque, and this could range from 30% to 50%. However, in a blowdown valve application where the valve outlet is opened to atmosphere, the valve will be subject to the full flowing pressure drop, and hence the RTO torque could be as high as or higher than the BTO torque in the case of butterfly valves.

The usual practice of applying a percentage on the BTO torque is not a good practice because BTO torques will be lower at lower shutoff pressures, hence, the RTO torque calculated by this method could become much lower than actual.

Actuators selected using the percentage method provided by manufacturers will not perform under these conditions, although they may work when they were bench-stroked without pressure.

End to Open Torque

End To Open, or ETO torque, is the torque of the valve at fully open position.

Similar to the BTO and RTO torque, the ETO torque is affected by flowing media and seat / packing materials, and by the flowing pressure drop through the valve.

Heaton calculates this precisely using engineering software instead of the common industrial practice of taking the ETO torque as a percentage of the BTO torque.

Break to Close Torque

Break To Close, or BTC torque, is the torque needed to start closing the valve at operating pressure.

Similarly, the BTC torque is affected by flowing media and seat / packing materials, and by the operating pressure through the valve.

Many manufacturers calculate BTC torque as a percentage of the BTO torque, and make mistakes similar to the RTO torque mistakes discussed earlier.

Run to Close Torque

Run To Close, or RTC torque, is the torque to stroke the valve before its fully close position after the valve has started to close.

Similarly to the RTO torque, the RTC torque is affected by flowing media and seat / packing materials, and by the flowing pressure drop through the valve.

A common assumption is that RTC torque is the same as RTO torque, but the flowing pressure drops during opening and closing strokes are always different. This is especially so for Emergency Shutoff Valves when they are activated due to line breaks downstream, which increase the flowing pressure drop, hence increasing the RTC torque.

Unfortunately this assumption results in the same mistakes made as with the RTO torque.

End to Close Torque

End To Close, or ETC torque, is the torque to close the valve at its fully close position.

Similarly, the ETC torque is affected by flowing media and seat / packing materials, and by the pressure drop across the valve.

As with the other torques for the valve, Heaton calculates them individually using in-house sizing software.

Heaton Ball Valve Sizing Program

Shown below the program that can calculate the valve torques accurately for different fluid types, pressure drops, temperature, seat materials, etc.

Actuator Selection and Optimization Process

Actuation selection can only begin once the valve torques are accurately determined. A common industry practice is to select actuators with a safety factor throughout the stroking range to provide for future valve torque increases due to long term stationary positions during operation, deposit buildup, wear and tear, etc.

The common industry practice is to size actuators based on the minimum available air pressure and add on the safety factor required. However, this simple process of sizing actuators does not provide the best match possible between the valve and actuator. The Heaton Advance Actuator Sizing program, not only calculates the above but also determine the lowest pressure at which the actuator will still provide the required safety factor, and these information will be used to optimize the actuator selection and operation.

Lower pressures used will mean lesser air consumption, and hence, savings in compressed air or energy used in generating the compressed air.

Advance Actuator Sizing & Optimization Program

Shown below is the Advance Sizing program. It is extremely easy to use with many actuator brands to select from. This in house developed program is not found anywhere else except at Heaton Valves

Advance Actuator Sizing & Optimization Program

Shown below is the Actuator Optimization page in the Advance Sizing program. It provides all information necessary in making a proper selection and recommendation on the pressure usage.

Advance Actuator Sizing & Optimization Program

Shown below is the Advance Sizing printout. It also calculates stroking speed when instrument Cv’s are input..

Other Types of Actuator Sizing

What about electric actuators ? Can they be optimized ? At Heaton, nothing is impossible for us. The cost savings on optimizing electric actuation is even greater than pneumatic actuation!

Sizing and optimization programs are also available for electric actuators selection covering both quarter turn and linear valve constructions. These programs will consider all actuator and gearbox combinations available to select the smallest and least power consuming actuator.

Contact us for your actuated valves requirement and you will be able to reduce your total cost of ownership with our trademark optimization programs. Help reduce Global Warming by Optimizing your flow control needs today.

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Total Cost of Ownership

Total cost of ownership of valves in a plant depends on many factors. These factors have to be considered from the design stage of the plant to the operation of the valves. Valves are designed for different service requirements of the plant. These valves are also installed and operated differently from each other.

Many preventable mistakes are unknowingly made in newly built plants which often result in financial losses. Financial loss comes in terms of valve failures that cause plant shutdowns, frequent maintenance or replacements, and increased operational costs.

These can be prevented by selecting the correct valves and through proper installation, operation and maintenance, allow the valves to perform to its designed life span at the lowest operational cost.

Optimization of Valve Actuation

Total cost of ownership can be reduced tremendously through proper planning of the following:

  1. Design stage. As an example, piping should be designed to allocate proper ( in terms of proximity to pipe fittings ) and sufficient space for valves to be installed correctly.
  2. Considerations of the process and service conditions to allow the correct valve types to be selected.
  3. Selecting a properly designed valve and optimized actuated valve package
  4. Proper handling of the valves from the factory to the site and to where they are to be installed.
  5. Operating the valves correctly
  6. Maintaining the valves correctly

Once the above is done, the total cost of ownership will be reduced to its minimum. Read more to learn more on how you can reduce your total cost of ownership.

Valve Design

Valve designs are critical to good valve performance.

The difference in price for a properly designed trunnion mounted ball valve and that of a poorly designed one can be more than 50%. An example would be an integral ball and trunnion design which helps to prevent premature stem seal wear due to stem lateral movement. Without this feature, the poorly designed valve will fail more often and may need to be replaced numerous times than needed.

Heaton Valves includes all these additional features as part of our standard production valves to enhance the performance and service life.

Contact us for more information.

Valve Application

A wrong valve used for the service can mean constant financial loss to any operating plant. A properly designed valve used in the wrong application will also fail regardless of valve design and quality. Therefore, it is extremely important to select the correct valve for the proper application and service.

For example, a gate valve or a normal globe valve will not perform well in high flowing pressure drop throttling service. These valves will not work well and can result in failures, requiring multiple replacements. The quantum of high flowing pressure drop is dependant on the valve type.

Valve Application

Certain factors such as dynamic torque, plays an important part for large size butterfly valves. A 3 bar flowing pressure drop for this size will generate a torque that can be higher than its break torque.

As an actuator is usually sized based on the BTO torque without consideration of the dynamic torque, this results in the valve getting “stuck” at 30% opening position. The valve stem can even shear if the actuator torque is greater than the valve stem maximum allowable shear torque. Hence replacing the failed valve with the same valve will continue to result in the same problems.

Valve Application

Heaton is able to provide custom designed throttling globe valves for manual operation and this is an excellent solution for large size throttling requirements. The cost savings in using a control valve for manual throttling can be 50% or more.

All types of valves are designed for specific needs and hence cannot be used in all kinds of applications.

Contact us for your valve application requirements.

Valve Handling

Proper valve handling, including shipping and storage at site during construction of the plant, is vital to its operational performance. There are many instances where valves were rough handled, dropped, left exposed under the weather, etc, prior to installation. Although valves may be made of steel, their seating and sealing surfaces are very delicate. Once damaged, the valve may not be able to seal tightly, and a misaligned valve wedge will not be seated properly causing leakage. A common mistake is opening a large gate valve when the valve is lying on its side, and leaving it in the open or partially open position, before transporting it to the site for installation. This action would most likely cause the valve to leak when it is commissioned due to the misaligned wedge. Gate valves must never be opened while lying on its side and must always be closed tightly during transportation to prevent misalignment of the wedge.

Contact us for proper valve handling requirements for all valve types.

Valve Installation

Certain valves are designed only to be installed in a particular orientation. Gate valves for example, are designed to be installed with the stem in the vertical position. There are many instances where gate valves are installed in different ways other than the above, due to space constraints, and plant design or convenience of operation, especially for a large size valve. This will cause repeated failures and shorten the operating life of the valve by more than 50%. Many incorrectly installed valves are replaced year after year without knowing that a simple correction in the installation will solve and rectify the problem.

Contact us for any installation problems you may have.

Valve Operation

After valves are installed and in operation, operating them correctly is crucial to the performance of the valves. Some valves are meant to be either in the fully close or fully open positions, and setting them in any intermediate open positions can damage them.

Contact us for more information on many other valve operation requirements.

Valve Maintenance

Valves, like any other equipment, require maintenance for them to perform as designed. Simple maintenance such as stem packing inspections and adjustments can prolong valve service life especially in steam service.

Contact us for more information on other maintenance that can extend the service life for valves.

Heaton Ball Valve Sizing Program

Shown below the program that can calculate the valve torques accurately for different fluid types, pressure drops, temperature, seat materials, etc.

Welcome to our engineering solutions page

With our vast knowledge in valves application and actuation, we would like to improve your plant performance to achieve operational excellence. Our engineering solutions can assist to lower your total cost of ownership for your valves and actuators. Heaton, using its vast engineering knowledge and experience, manufactures a wide range of valves to cater to the demands of the industries. Heaton is proud to have manufactured valves which continue to be in service after 40 years, due to excellent design, proper application, handling, installation and operation. Please contact us with your requirements and service conditions for any technical advice that you may be looking for.

Read our articles in this page to understand more.

Please write to us your requirements with the service conditions, or simply contact us and we will get back to you.