How to choose the right Valve Materials for Valves

June 1

There are several factors to consider when choosing materials for your valves. First, you must evaluate which media they will manage. The material must be capable of withstanding the press that is regularly present in the line and media that may enter the line or the external environment around the valve.

Then you also need to consider:

  • The specific requirements of your application
  •  Process conditions 
  • And compatibility requirements

Material selection is crucial to assuring long-term performance, dependability, and safety. This post will discuss some of the most popular media and appropriate resources.

Chemical as Valve Manufacturing Material

The chemical compatibility of valve materials varies according to the individual substances involved. Some materials may corrode, resulting in rust. The suitability of a material is determined by its resistance to corrosion induced by the liquid or gas being handled. However, certain materials are frequently utilized due to their chemical resistance.

We offer several valve materials for chemical applications. Here are some of them and their usual chemical compatibilities:

Stainless Steel (EN 1.4408 and 1.4409): Stainless steel (EN 1.4408 and 1.4409) is commonly utilized due to its high corrosion resistance. It is compatible with various chemicals, including acids (such as sulfuric acid, and hydrochloric acid), alkalis, organic solvents, and many corrosive fluids.

Titanium is a substance that can survive chlorides, which are present in salt water and chemicals. While titanium is more expensive, its lightweight design can reduce the cost of transportation, operation, and maintenance.

Steel alloys such as acid-resistant steel (EN 1.4409, EN 1.4408) are often used, however for stronger corrosion resistance, duplex, super duplex, 904L, or SMO grades such as 254 may be suitable at lower chloride concentrations, such as saltwater, and lower temperatures. Unlike more costly acid-resistant steels, carbon steel and cast iron corrode quickly in an industrial setting.

Hastelloy: Hastelloy alloys (such as Hastelloy C276) are highly resistant to various corrosive substances, including strong acids, alkalis, oxidizing agents, and severe conditions. They are widely employed in demanding chemical processing applications.

Gas Media as Valve Manufacturing Material: 

The compatibility of valve materials with gases varies depending on the gas being handled. Helium, for example, is a complicated gas to separate. Hydrogen atoms are driven into the material, causing damage to the valve from the inside, a process known as hydrogen embrittlement. Helium requires the proper substance in the valve for the seals to hold.

The release of hazardous gases or gases with a climatic impact on the atmosphere is an issue in all sectors. The problem can be avoided or mitigated by employing valves that fulfill the fugitive emission criteria specified in ISO 15848-1 and VDI 2440 (TA-luft).

Here are some of the materials we utilize in our valves, along with their general gas compatibility:


Stainless Steel (EN 1.4408 and 1.4409): Stainless Steel valves can handle various gases, including inert gases, hydrocarbons, and non-corrosive gases. Stainless Steel is corrosion-resistant and can endure high-pressure, high-temperature gas applications. Furthermore, stainless steel is particularly resistant to hydrogen embrittlement, making it a safe and dependable material for hydrogen gas applications.

Hastelloy alloys, like Hastelloy C276, are extremely resistant to corrosive gasses, whether acidic or alkaline. They are widely employed in harsh gas processing applications that need excellent corrosion resistance.

Duplex and super duplex materials (e.g., SAF 2205, SAF 2507) offer better corrosion resistance in harsh settings, making them ideal for handling corrosive gasses. These materials are highly resistant to pitting, crevice corrosion, and stress corrosion cracking. Duplex and super duplex valves are widely employed in offshore, chemical, and oil and gas applications where strong chloride or acidic gasses are present.

904L is a high-alloy austenitic stainless steel renowned for its exceptional resistance to a wide range of hostile media, including sulfuric acid, phosphoric acid, and other acid gasses. It has high strength and toughness, making it ideal for use in the gas sector, chemical processing, pulp and paper manufacturing, and other applications involving corrosive gases.

254SMO (EN 1.4547), a super-austenitic stainless steel, is highly resistant to a variety of corrosive gasses, including sulfuric acid, hydrochloric acid, and acetic acid. It is extremely resistant to pitting, crevice corrosion, and stress corrosion cracking, even in hard conditions. 254SMO valves are widely used in chemical, pulp paper, and offshore industries.

Titanium

Titanium is extremely resistant to a variety of corrosive gasses, including wet chlorine, hydrochloric acid, and many organic chemicals. It is exceptionally resistant to pitting and crevice corrosion and retains its integrity at high temperatures. Titanium valves are used in the chemical and petrochemical industries, as well as in other areas that need great corrosion resistance.

There are several grades of titanium. The grades relate to different titanium alloys or compositions and are identified by numbers or alphanumeric codes, with each indicating a distinct composition and set of attributes. The most common grade for valves is 5, however, grade 2 is occasionally utilized. The choice of grade is determined by the application’s unique needs.

In this section, we will look at two valve materials that are appropriate for slurry applications: cast iron with natural rubber lining and stainless steel highlighting their respective strengths and concerns.

Cast Iron with Natural Rubber Lining: Cast iron valves with a natural rubber liner are ideal for managing slurries at low pressures and temperatures. The cast iron body ensures structural stability, while the natural rubber lining provides excellent resilience and abrasion resistance. These valves are especially useful in sectors like mining, steel mills, and wastewater treatment, where slurries are present. They offer dependable sealing, decrease wear, and lower the chance of leakage. However, cast iron with a natural rubber liner is not intended for extremely corrosive media or applications involving high pressures and temperatures.

Stainless Steel with SuperExpanite® treatment: Stainless steel valves with SuperExpanite® treatment offer outstanding resistance to corrosion and aggressive media. The SuperExpanite® treatment is a hardening procedure that dramatically increases the hardness and wear resistance of the base material.

This treatment makes the valve more durable and resistant to wear and erosion. Stainless steel valves with Expanite treatment are ideal for a variety of applications, including mining, steel plants, pulp and paper, power plants, food and beverage processing, and the chemical sector. They thrive in areas where abrasion resistance, lifespan, and dependability are critical while being less expensive than alternative options such as ceramic valves.

To summarize, cast iron valves with a natural rubber lining are appropriate for low-pressure, low-temperature applications with non-corrosive slurry. Stainless steel valves with SuperExpanite® treatment provide greater resistance and endurance in more demanding slurry conditions such as higher pressures, temperatures, and corrosive media.

How to Define the level of Quality

When selecting material for your valve, it might be difficult to establish the appropriate degree of quality. Higher alloys like titanium need significant investment, but lower-cost materials frequently necessitate greater maintenance and/or reduced production capacity.

One item of advice is to avoid using plastic or other composite materials, which are less expensive than typical metal valves. They have far lower pressure ratings, and because plastic is constantly exposed to UV radiation from sunlight, the valve will shatter under even the slightest pressure. This might result in significant additional expenditures and perhaps accidents.

To assist you in determining the proper degree of quality, we’ve compiled a list of key variables to consider:

  • Service life
  • Maintenance Intervals
  • Spare parts requirements
  • Wear and Tear
  • Production losses and delays
  • Fluid Compatibility 
  • Pressure and Temperature Ratings
  • Materials Strength
  • Corrosion Resistance
  • Abrasion Resistance
  • Environmental Factors
  • Cost Considerations 

Aira Euro Automation is the leading Valve Manufacturer in Ahmedabad, India. We are well-known for manufacturing the best quality Pneumatic Ball valves, Pneumatic Control Valves, and Pneumatic Butterfly valves. Feel free to contact us if need guidance in choosing the most suitable valve material for your valve.