How to select O-ring for sanitary valve
Oring gasket is a small spare parts but very important for sanitary valve , Low-quality seal or inappropriate application can cause many problems E.g. leaking, swelling or cracking. It will affect valve lifetime. Donjoy valve gasket import from AVK with good quality
Types of O-ring seal
- EPDM rubber (ethylene propylene diene monomer rubber)is a type of synthetic rubber which is suitable for most application .
- Teflon(PTFE) Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications.
- Viton(FPM) Viton is a brand of FKM, a synthetic rubber and fluoropolymer elastomer commonly used in seals, chemical-resistant gloves, and other molded or extruded goods.
- Silicon rubber is an elastomer (rubber-like material), usually used in pharmaceutical industry.
- NBR Nitrile rubber, also known as nitrile butadiene rubber, NBR, Buna-N, and acrylonitrile butadiene rubber, is a synthetic rubber derived from acrylonitrile (ACN) and butadiene. Suitalb efor oil medium .
The temperature and chemical compatibility
| Material | Temperature | Chemical Compatibility |
| EPDM | -10 – 130 °C (14 – 266°F) | good resistance to acid and alkali, good abrasive resistance |
| Teflon(PTFE) | -20 – 150 °C (-4 – 302°F) | good resistance to acid and alkali，better abrasive resistance，inelastic material |
| Viton(FPM) | -10 – 130 °C (14 – 266°F) | great resistance to acid and alkali, ozone |
| Silicon rubber | -30 – 130 °C (-22 – 302°F) | bad resistance to acid and alkali, |
| NBR | -5 – 100 °C (23 – 212°F) | the best use for oil or fat products, good resistance to acid and alkali |
Donjoiy santiary ball valve
PTFE seal is hard seal which is suitable for ball valve , angle seatl valve , globe valve , it suitable for higher temperature max 150 degree
Donjoy butterfly valve gasket
Donjoy diaphragm valve gasket
In addition to the valve body, the gasket is the only direct contact with media parts. Diaphragm valves rely on a diaphragm membrane to isolate the medium from the actuator and the external air. The diaphragm is also a moving part, the membrane moves up and down by the diaphragm to control the flow of the medium or cut off.
Donjoy diaphragms valve membrane has been developed and tested over many years according to our own testing methods and standards and under strict third party specifications.
Single gasket for diaphragm valve
The rubber diaphragm is embedded with a layer of vulcanised fibres to enhance its mechanical properties, the diaphragm has high sealing stability at elevated pressures and temperatures and the reinforcing fibres are hardened on the stainless steel bolts, thus ensuring a better bonding of the rubber to the metal.
Size : 1/4" to 4 inch
Temperature : EPDM -10 – 120 °C (14 – 248°F)
Double adhesive diaphragm seal
PTFE diaphragm is highly resistant to chemicals, extremely stable, resilient, long-lasting, highly leak-tight, non-cold degradable and have excellent resistance to temperature fluctuations, whether in hot, cold or steam sterilisation systems.
Size : 1/4" to 4 inch
Temperature : EPDM -10 – 120 °C (-4 – 248°F)
Double separately diaphragm seal
The diaphragm consists of EPDM and PTFE. The special feature of the modified diaphragm is that the diaphragm itself is shaped to seal against the valve body when the valve is in the closed position, thus reducing the diaphragm load and extending its service life. The diaphragm can withstand higher temperatures and severe working conditions.
Size : 1/4" to 4 inch
Temperature : EPDM -10 – 150 °C (-4 – 302°F)
