Key Takeaways
- Chemical process plants use control, isolation, check and pressure relief valves, with the selection driven by media compatibility before anything else.
- Material compatibility outranks valve style. The wrong body or trim alloy fails in weeks regardless of how well the valve type suits the duty.
- Corrosive service and abrasive service require different answers. Corrosion calls for alloy selection and lined designs; abrasion calls for hardened trim and a sealing surface that resists washout.
- Fugitive emissions requirements shape stem sealing and packing selection in chemical service more than in most other industries.
- Where a chemical stream carries catalyst, solids or crystallizing media, the valve must keep its sealing surfaces clear. Conventional valves that trap solids in the seat pocket fail early regardless of alloy.
The chemical industry relies on a multitude of equipment, and among them, valves play a pivotal role. Valves are indispensable devices that control the flow of liquids and gases, ensuring the smooth and safe operation of chemical processes.
If you work with chemicals every day, you may have often wondered what the most common types of valves used in the chemical industry are. This article is the guide for you.
We’re going to take a detailed look at these valves, their applications, and the key roles they play in the production of essential chemical products.
Valve Applications in the Chemical Industry
Valves are indispensable tools in the chemical industry, serving multiple applications. They are instrumental in regulating the flow of liquids, gases, and steam in various processes.
Control Valves
Control valves are the workhorses of the chemical industry. They are used for precise control over fluid flow, pressure, and temperature, essential for maintaining the quality and consistency of chemical products. These valves can be adjusted to manage the rate at which substances move through pipelines, ensuring that chemical reactions proceed optimally.
Control valves come in various designs, including globe valves, butterfly valves, and plug valves, each suited to different process requirements.
In the chemical industry, they are frequently employed to regulate the flow of reactants, control temperature, and manage pressure in reactors, distillation columns, and other crucial equipment.
Ball Valves
Ball valves are commonly used in the chemical industry for their simplicity and efficiency. They consist of a ball-shaped disc that rotates to control the flow of fluid. When the valve is in the open position, the fluid flows freely through the hollow center of the ball, and when closed, the ball seals the passage.
Ball valves are highly reliable and versatile, making them suitable for a wide range of chemical applications.
They are often used to shut off or isolate sections of a pipeline, making maintenance and repairs more manageable. Their design also minimizes the risk of leaks, making them ideal for handling hazardous chemicals.
Slide Gate Valves
Slide-gate valves are another critical component in the chemical industry. These valves employ a sliding gate or plate to control the flow of materials. The gate can be fully opened, fully closed, or positioned partially to control the flow rate accurately.
These valves are particularly useful for handling abrasive and granular materials in the chemical industry. They can be found in applications such as controlling the discharge of powders, grains, and bulk solids from hoppers, silos, and chutes.
The design of slide gate valves minimizes the potential for material buildup and blockages, which is crucial when dealing with abrasive substances.
Types of Valves Used in the Chemical Industry
The chemical industry relies on various types of valves to meet its diverse needs. Each type of valve is designed to excel in specific applications, ensuring that chemical processes run smoothly and safely.
Gate Valves
Gate valves are recognized for their full opening and closing capabilities, which allow for minimal fluid flow restriction.
In the chemical industry, gate valves find applications in situations where a straight-line flow and tight shut-off are necessary. They are often used in large-diameter pipelines and high-pressure systems, making them a suitable choice for the transportation of chemicals.
Globe Valves
Globe valves are characterized by their spherical-shaped bodies and a movable disc that regulates the flow of fluids. They are known for their exceptional throttling capabilities, making them suitable for applications where precise control is required.
Globe valves are often used in the chemical industry for applications such as flow regulation, pressure control, and fluid isolation.
Check Valves
Check valves, also known as non-return valves, are essential for preventing the reverse flow of fluids in pipelines. They are crucial in systems where maintaining a unidirectional flow is imperative, such as in pumps, compressors, and piping systems.
In the chemical industry, check valves help maintain the integrity of the process by preventing backflow, which could compromise safety and efficiency.
Diaphragm Valves
Diaphragm valves feature a flexible diaphragm or membrane that isolates the valve body from the process fluid.
This design makes them suitable for handling corrosive and abrasive chemicals. Diaphragm valves are frequently used in applications where contamination must be minimized, such as in the pharmaceutical and specialty chemical sectors.
Butterfly Valves
Butterfly valves are appreciated for their lightweight, low-profile design and rapid quarter-turn operation. They are well-suited for large-diameter pipelines and are used in the chemical industry for isolating or regulating the flow of liquids, gases, and slurries.
Butterfly valves are cost-effective and provide reliable shut-off capabilities, making them a popular choice for various chemical applications.
Plug Valves
Plug valves are versatile devices that feature a cylindrical or tapered plug to control fluid flow. They offer low torque requirements and quick quarter-turn operation, making them suitable for applications requiring frequent cycling.
Plug valves are used for various purposes within the industry, including flow control, on-off applications, and the handling of corrosive or abrasive fluids.
Valve Maintenance and Longevity
Ensuring the longevity of valves in the chemical industry is not just about selecting the right type but also about proper maintenance. Regular inspections, cleaning, and replacing worn components are essential for extending the lifespan of valves.
Preventive measures can reduce downtime and operational disruptions, ultimately saving costs. With well-maintained valves, the chemical industry can maintain consistent production and safety standards.
All of these things can address problems proactively, further enhancing the reliability and durability of these critical components.
Get the Right Valves Today
Valves are the unsung heroes of the chemical industry, silently ensuring the safe and efficient handling of diverse substances. The choice of valve type is critical in optimizing processes, ensuring safety, and maintaining product quality.
Everlasting Valve Company is a leading provider of cutting-edge valve solutions. Specializing in innovative, self-lapping, rotating-disc valves, we serve a wide range of industries, including the chemical industry. With a commitment to durability and reliability,
Everlasting Valve’s products are designed to withstand even the most demanding applications. Get in touch with us today to find solutions to your valve needs.
Frequently Asked Questions
Control valves for regulating flow, pressure and temperature; ball, gate and butterfly valves for isolation; check valves to prevent backflow; and pressure relief valves for protection. Diaphragm and plug valves appear where the media is corrosive or carries solids.
Media compatibility with the wetted materials. The body alloy, trim, seat and packing all have to survive the chemistry at operating temperature. A valve style that fits the duty perfectly will still fail quickly if the material selection is wrong.
Lined valves and high-alloy bodies. Diaphragm valves isolate the working parts from the media entirely, which suits aggressive chemistry at moderate pressure. Where pressure or temperature rules out a liner, the answer moves to alloy selection in the valve body and trim.
Prioritize designs that keep solids out of the sealing area. An open body cavity lets particulate move through rather than pack into pockets, and a sealing surface that is wiped clean as the valve cycles will hold shutoff far longer than a seat that traps media. Alloy selection then addresses the corrosion side.
It varies widely by process, from cryogenic service well below zero to catalyst and reactor duty above 1000 degrees F. Everlasting process valves are rated from minus 50 degrees F to 1500 degrees F, which covers most chemical and petrochemical process conditions in a single platform.