Solenoid valves are used to control a wide range of fluid and gas media. In most instances for general purpose applications such as ambient temperature air, water and atmospheric gases a standard Brass solenoid valves with NBR seals will be suitable.
How ever solenoid valves are manufactured from a range of materials such as Brass, 304 Stainless Steel, 316 Stainless Steel, Cast Steel, Cast Iron, Ductile Iron, Bronze, Aluminium and various Plastics such as Nylon, PVC, PVDF, PP and PTFE with options for various seal materials such as NBR, FKM (Viton®), EPDM and PTFE (Teflon®). These various materials of construction and choice of elastomer sealing are designed to cope with more aggressive and corrosive acid and alkali media.
Solenoid valve users are frequently faced with challenging applications were the media being controlled must be compatible with the materials of construction of the valve.
This user friendly material chemical resistance chart is offered as guidance, we would strongly recommend that ever application is checked with the solenoid valve supplier for application compatibility. In some instances the chemicals being used will be brand names, and in this instance it is best practice to contact the technical team or laboratory of the chemical manufacturers to obtain a list of approved and suitable valve materials
Selecting the correct seal for a solenoid valve requires some understanding of the available seal materials in the market today. With so may options for valve materials of construction we have compiled some basic information to assist in choosing the correct valve seal.
These are guide minimum and maximum elastomer seal working temperature parameters, which can be achieved with the best grades of sealing material, lesser grades or cheaper materials will have significantly limited ranges, so please check with your material supplier
|Seal||Min Temp||Max Temp|
|Seal||Min Temp||Max Temp|
|Nitrile General service||-34°C||+121°C|
|Nitrile Low Temperature||-55°C||+107°C|
|Seal||Min Temp||Max Temp|
The chemical name for this EPDM rubber is Ethylene Propylene Diene Monomer rubber. EPDM seals in solenoid valves are well suited for use with hot water, low pressure steam (130°C Max) due to EPDM excellent resistance to heat and offer excellent weather resistance. The maximum working temperature of EPDM is approximately 120-130 degrees Celsius. EPDM is unsuitable for most oils and fuels.
HNBR or Hydrogenated NBR is also known as HSN Highly Satuarated Nitrile rubber is an Buna Rubber with a high saturation of Butadiene Carbon Polymer giving improved chemical, abrasion resistance and dynamic loading resistance compared to standard NBR. Temperature range +150C Max.
Hypalon is similar to Neoprene but with improved acid resistance. Temperature range -17C to +104C
The chemical name for this rubber is Nitrile Rubber is Butadiene Acrylonitrile, however it is typically known as NBR or Buna-N. NBR is probably the most typically used seal for most valves and is the standard seal used by most valve manufacturers for neutral fluids and gases for general purpose applications. NBR is the standard material used by most O ring seals.
NBR will typically withstand temperatures up to +90°C on a continuous basis and can with stand slightly higher temperatures for a short period of time before hardening.
In additional to being used as a solenoid valve seal, NBR is also found in water pumps, carburettor, transmissions, hydraulic pumps and hydraulic actuator seals.
A low compression flame resistant polymer. Temperature range -29C to +107C
Peek Polyetheretherketone is an organic thermosplastic polymer with strong chemicsl, thermal and mechanical resistance, excellent for medical implants. Temperature range -40C to +340C
Teflon is a brand name for PTFE which stands for Polytetrafluoroethylene. PTFE is resistant to most liquids. Not suited to liquid alkali's and Fluorine.PTFE is non elastic (not flexible), so this limits is sealing capabilities for certain applications. PTFE can reach very high temperatures up to +230°C, but gives off poisonous gases above +250°C, and is commonly used for cryogenic applications down beyond -200°C. PTFE is the preferred seal for very high pressure solenoid valves, aggressive and corrosive media and extreme temperature applications such as high pressure steam. Virgin PTFE accepted by FDA for food use.
Is a 15% glass reinforced tetrafluoroethylene that adds to the pressure that PTFE can withstand. 15% RTFE is not suitable for due to the reaction with the glass reinforcement. Temperature range -40C to +232C.
Is a 25% glass reinforced tetrafluoroethylene that adds to the pressure that 15% RTFE can withstand. Temperature range -40C to +232C.
Silicone (VQM) elastomer seals offers a wide working temperature range from -54°C through to +232°C, but Silicone is a very soft material and therefore is not very good with higher pressure applications typically above 40 bar (depending on orifice size and design).
TFM is a modified TFE tetrafluoroethylene polymer that the same PTDE chemical and heat resistance but with a denser TF polymer construction offers better stress recovery suited to seat, seal and gaskets for valve applications. WRAS, 3A and FDA approved material. Temperature range -40C to +260C.
TFM® 1600 filled with Amorphous Glass powder and graphite offering huge reduction in thermal expansion co-efficient (expansion due to heat) making it ideal sealing material for steam and other high temperature valves. Temperature range +40C to +260C, or +320C for liquid media.
Ultra High Molecular Weight Polyethylene (UHMWPE) also referred to as High Modulas Polyethylene (HMPE) or High Performance Polyethylene (HPPE) is a very strong seal material.
Viton is a brand name for a Fluoroelastomer. FKM is well know for its excellent heat resistance, making service temperatures up to +150°C obtainable.
Zurcon Z80 is a brand name for virgin ultra high molecular weight Polyethylene or UHMWPE. Zurcon offers zero water absorption and extreme abrasion resistance that is 500% more abrasion resistant than PTFE and is ideally suited for water, food and pharmaceutical processes. Working temperature ranges -120°C to +93°C, beyond this the wear and abrasion properties reduce, with short static maximums ranges from -200°C to +200°C.
Zurcon Z80 offers a virtually dry friction coefficient that even outperforms most PTFE compound seals offering a self lubricating non stick surface.
Please find below a range of solenoid valve seal material and body material liquids, gas chemical compatibility guides offering 302 stainless steel, 304 stainless steel, 316 stainless steel, 440 stainless steel, Aluminium, Titanium,, Hastelloy C, Cast Bronze, Cast Iron, Carbon Steel, PVC, Polyacetal, Nylon, ABS, Polyethelyene, Polypropylene, Rylon, Carbon, Viton (FKM), Buna N (NBR), Silicone, Neoprene, Ethylene Propylene (EPDM), Natural Rubber, and Epoxy chemical resistance guides E excellent - G Good resistance - M moderate resistance and X not recommended for everything from Acetaldehyde through to Zinc Sulphate.