Choosing Solenoid Valve Bodies & Seals

Solenoid valves are electronically controlled valves that help regulate the flow of a variety of liquids and gases in differing environments. A widely used application, solenoid valves are employed just about everywhere - controlling the dispensing of beverages in fountain drink dispensers, regulating blood flow in dialysis machines, managing air pressure in air conditioners, and much more.

The differing media these devices handle and differences in their operating environments necessitate that solenoid valves be made of materials that suit their circumstances. Valves that operate in high temperatures need to be able to accommodate the heat. Valves handling acidic media need to be resistant to corrosion. Solenoid valve manufacturers make various valves using a variety of components to meet these many different needs.

Knowing what valve and seal materials work best with various media helps those responsible for choosing a valve for an application make the right decision.

Factors to Consider When Choosing Valves and Seals

When choosing solenoid valve and seal materials, managers and engineers should keep the following in mind:

  • Media type - The type of media passing through a solenoid valve will have a huge impact on what valve and seal materials are most appropriate for the valve. Media that is highly corrosive will need to pass through valves made of material that can handle the media.
  • Environment - What type of environment is the valve working in? Is it a high temperature washer? Is it outside at a car wash where it will be exposed to varying extremes of temperature? Is it in an industrial application where corrosive materials will abound? The valve chosen needs to be able to withstand the elements in its operating environment.
  • Cost - Valve and seal materials will have varying costs, depending on how expensive they are to produce. Less expensive options may be better in some circumstances, even if they are not as rugged and reliable as more costly valves.
  • Safety - Solenoid valves used to regulate liquid food products will need to conform to safety guidelines regarding the materials used in their manufacture.

Common Valve Body Materials & Their Uses

  • Polyphenyl Sulphide - For high temperature applications, solenoid valve bodies made from polyphenyl sulphide (PPS) do very well. This material can perform at temperatures above 200°C and exhibits strong resistance to corrosion from acids and alkalis. Rugged and tough, this material also can be bumped and bounced without damage. PPS is a thermoplastic that is used for many applications in several industries.
  • Polyvinylidene Flouride - Solenoid valve manufacturers have found that polyvinylidene fluoride is easy to mold and weld, making it a good material to make valve bodies from. PVDF solenoid valve bodies are very resistant to solvents, acids, and bases, but do not handle high temperatures well.
  • Polyether Ether Ketone - Polyether ether ketone provides users with superior mechanical and chemical properties and is a premium solenoid valve body material. Quality comes with a price, however, as PEEK solenoid valve bodies tend to be more expensive than other options. The material also is vulnerable to highly concentrated amounts of sulphuric acid and nitric acid.

Solenoid valve bodies are also frequently made from metal. Some of the most common solenoid valve metal bodies are made of stainless steel, brass, and aluminum.

Common Seal Materials & Their Uses

  • Ethylene Propylene Terpolymer - This is the most widely used material for solenoid valve seals. Solenoid valve manufacturers prefer it because of its resistance to acids, alkalis, and salts. The material is useful in temperatures up to 90°C. One drawback of EPDM rubber is that it does not work well with oils, petrochemicals and concentrated acids. It's best suited for hot and cold water, Freon, and air.
  • Polytrafluoroethylene - Solenoid valve manufacturers use this material for applications needing strong resistance to chemical corrosion. PTFE is chemically inert, nearly impossible to dissolve, and can withstand high temperatures.
  • Nitrile Rubber - Nitrile rubber has a high chemical resistance, making it ideal for seals in valves used to regulate oils and petroleum. NBR also has great abrasion resistance. It does not handle oxidizing media well, however.
  • NBR is most commonly used in applications involving water, air, oils, and gases. It is ill-suited for chlorinated hydrocarbons, ethers and esters, as well as methyl ethyl ketone and ozone acetone. It is much cheaper than FKM/FFKM.
  • Flourinated Elastomer/Perfluoro Elastomer - Solenoid valve manufacturers use this seal material for applications where maximum heat and chemical resistance is needed. While more expensive than NBR, FKM/FFKM handles temperatures above 200°C very well. This seal material is typically used in applications involving hot water, acid, salts, hydrocarbons and oils.

In addition to these seal materials, other materials are also frequently used for solenoid valves. Some of these materials include Teflon, neoprene, polyurethane and standard neoprene.

Valve Design

Design is also an important factor for solenoid valves. In general, plunger-style direct acting solenoid valves work best with neutral and clean liquid media, while pivoted armature solenoid valves work best for corrosive or potentially hazardous fluids.

Solenoid valves allow for the convenient, accurate flow of liquid and gas media. When the right valve is paired with the right media and operating environment, these electronically controlled devices yield greater efficiency, control, and safety for their users.

Experience Matters

When choosing solenoid valves, consulting with experienced solenoid valve manufacturers can help ensure that a reliable, cost-effective option is chosen. Solenoid Solutions has decades of experience in providing custom-made solenoid valves that meet client specifications. With a state-of-the-art manufacturing shop, Solenoid Solutions can quickly manufacture high quality valves and help clients build up an inventory of valves for use as replacements when needed.