By Ivy Davis

Products made from chemicals support several industries, but also everyday life in several ways. In your own house, from your appliances, to your paint, to your furniture, chemical processing played an integral part in getting those products there. Chemicals also support personal care products, connective technology, help save energy, entertainment and equipment, and even more.

 

A large oil and gas company has dedicated a website to the benefits of chemicals to support modern life. Their website stated: “These varied end products help us to live, work and care. They can also help society respond to climate change. This is because they often have a lower carbon footprint over their lifecycle than alternative materials like wood, paper or metal. Or they help us to conserve energy or transition to a lower-carbon energy system. Insulation and low-temperature detergents save energy in our homes, for example. Light-weight components in cars and planes, modern tires and additives all improve fuel efficiency. Components help build wind turbines and solar panels.”1

Chemical companies process raw materials such as crude oil biproducts into more refined products. Crude oil has a tremendous impact on the chemicals industry because many plastics and polymers are manufactured from derivatives of crude oil. It is also probably no surprise that the chemical industry itself is the largest purchaser of chemical products and facilities are often located near other facilities, allowing for easy transport of chemicals. To that end, these materials must be transported in a safe and reliable manner from one location to the next.2

 

When considering crude oil versus chemicals, there are different contributing factors to move them through the pipeline and maintain accurate flow of the different products. Let us have a look at how actuators assist in accurately controlling products, and the best types of valves to use in chemical applications.

Fig1

Actuators and Control

An actuator is used to automate valves so that human interaction and decision making is limited for proper actuation, or movement of the valve. The actuator can use air, hydraulic fluid, or electricity to power, often referred to as pneumatic, electric actuators (or electro-hydraulic for chemical pipeline).

 

For optimal performance of an actuator, consider these takeaways:

 

• Precise, repeatable positioning typically better than 0.15% of span.

 

• The ability to start and stop instantaneously without dead time or position overshoot.

 

• Continuous duty rating without limitations on the number of starts per minute.

 

• Perform consistently and unaffected by load.

 

• Rugged industrial design capable of operating in difficult environments without an effect on performance.

 

• Minimal periodic maintenance required.3

 

The performance of an actuator that has been designed, tested, and maintained properly, will reduce risks while controlling the flow of chemicals with minimal human intervention.

 

Fig2

Valves and Chemicals

Valves are critical in the movement of products through a piping system while controlling flow, protecting equipment and providing safety in emergency shut off situations. Using just any valve in the chemical industry could wind up putting operators and the environment at risk. When selecting a valve for a chemical application, consider these takeaways:

 

• Choose valves that have been designed based on flow requirements needed to meet safety standards.

 

• Will the valve provide accurate flow control?

 

• Choose a valve designed to meet process requirements such as temperature and pressure.

 

• Is the valve capable of meeting allowable leak definitions for fugitive emissions?

 

• Will it prevent leakage of potentially hazardous material?

 

For valves regulating flow, there are several kinds to choose from. Globe valves contain spiral channels, which has high friction. Because of this, they have limited capability to regulate specific types of flow, unless they are viscous liquids. Gate valves have a metallic gateway, which can open and close. Due to this simplistic design, they also have limited flow control, as it is limited to either allowing flow or stopping it. Ball valves have a metallic ball in the center, and can offer bi-directional flow. This allows them to have a higher amount of flow than many other kinds. Check valves limit backward flow, with internal mechanisms that can help control flow, but are not ideal for high pressure or fast flowing liquids. Finally, butterfly valves include horizontal rotary motion, to allow or stop flow, with a paddle in the center. Butterfly valves are often used in the chemical industry because they can regulate flow of gas, liquids, and sometimes semi-solids.3

 

Additionally, we can narrow our focus to be more specific regarding valves and flow control to look at control valves as a key component of accuracy of process control. Control valves are designed to operate for the purpose of controlling various process conditions. Control valves work by either fully opening or closing, or somewhere in between to respond to a design and operating criteria. Control valves are typically designed to operate using signals programmed to a specific set point to meet process demands. Control valves consist of three main parts: the actuator, positioner, and body. There are many types and designs used based on the application.4

 

The use of chemicals is a precise process. Control valves must perform to exacting standards and meet all requirements and regulations. Control valves are used to add specific amounts of chemicals to another set of chemicals at exacting levels. In many industrial processing applications, control valves can be found operating in harsh environments. The valves are designed to handle all types of hazardous conditions while meeting or exceeding ASME B16.34 or other specifications. The proper and effective construction of these valves is very important relative to the intended performance and operation as part of the process applications.4

 

Control valves are found in but not limited to these industries:

 

• Chemical

 

• Refining

 

• Petrochemical

 

• Biofuels

 

• Food and beverage processing

 

• Mining

 

• Nuclear power

 

• Oil and gas processing

 

• Pharmaceutical

 

• Pulp and paper

 

Beyond valve selection, materials must also be considered. There are strict safety standards, depending on the flow media, for material selection. If a material is reactive with chemicals that will be exposed to the valves, it could be a safety and environmental hazard. Materials must also be chosen that will outstand extreme temperatures or varying pressures.5

 

To continue safe, reliable transportation and production of chemicals and raw materials, we must ensure the proper application of valves, actuators and all equipment used. This will help in the continued production of valued consumer goods to end users.

Fig3

REFERENCES

 
1. https://www.shell.com/business-customers/chemicals/the-benefits-of-chemicals-in-everyday-life.html
2. https://www.investopedia.com/ask/answers/042015/what-types-industries-are-main-consumers-productschemicals-
sector.asp
3. https://foundersguide.com/valves-and-actuators/
4. https://empoweringpumps.com/control-valves-used-in-the-chemical-industry/

5. https://www.pumpindustry.com.au/selecting-valves-considerations-by-industry-and-application

 

ABOUT THE AUTHOR

 

Ivy Davis began her career in 2007 with a Bachelors of Business Administration in Marketing from Texas Lutheran University. She was awarded the ‘Outstanding Marketing Award’ for the highest GPA in her graduating class and has since excelled as a marketing professional. Ivy continues to pursue her passion for marketing and regularly consults with organizations to facilitate marketing plans for exponential growth in their industry. She has worked in Houston, Texas for the last decade and focuses predominantly on the oil & gas and technology sectors.

Previous articleFeatured Story – Asset Integrity Management Systems – Part 15
Next articleDesktop Metal Acquires Aidro