O-ring is essential in the assembly process of the pump. The O-rings material shall be different to adapt pumped liquid. Fluororubber and EPDM are typically to use. Why? The following are the characteristics of these two materials.
Characteristics of fluororubber
Good stability
Fluororubber has a high degree of chemical stability and is currently the best medium for all elastomers. Fluororubber resistant to petroleum base oil, diester oil, silicone ether oil, silicic acid oil, resistant to inorganic acid, resistant to most organic and inorganic solvents, pharmaceuticals, etc., only not resistant to low molecular weight ketones, ethers, Ester, amine, ammonia, hydrofluoric acid, chlorosulfonic acid, phosphoric acid hydraulic oil.
High temperature resistance
Fluororubber has the best high-temperature resistance in the current elastomer. Bonve Pump with FFKM material can be continuous working at 280℃.
Aging resistance
Fluororubber has excellent weathering resistance and ozone resistance. It has been reported that the VitonA developed by DuPont has been performing satisfactorily after 10 years of natural storage, and there is no significant cracking in the air having an ozone concentration of 0.01% for 45 days.
Excellent mechanical properties
Fluororubber has excellent physical and mechanical properties. Fluororubber 26 generally has a strength of between 10 and 20 MPa, an elongation at break of between 150 and 350%, and a tear strength of between 3 and 4 KN/m. Fluororubber 23 has a strength between 15.0 and 25 MPa, an elongation of 200% to 600%, and a tear strength of between 2 and 7 MPa.
Characteristics of EPDM rubber
Low density and high filling
The density of EPDM is a lower rubber with a density of 0.87. In addition, the oil can be filled in a large amount and the filler is added, thereby reducing the cost of the rubber product.
Strong anti-aging properties
EPDM has excellent weather resistance, ozone resistance, heat resistance, acid and alkali resistance, water vapor resistance, color stability, electrical properties, oil-filling properties and fluidity at room temperature. EPDM products can be used for a long time at 120℃, and can be used temporarily or intermittently at 150-200℃. Adding a suitable anti-aging agent can increase its use temperature. EPDM rubber can be cracked for more than 150h under the condition of ozone concentration of 50pphm and stretching of 30%.
Good corrosion resistance
Due to the lack of polarity and low unsaturation of EPDM, it has good resistance to various polar chemicals such as alcohols, acids, alkalis, oxidants, refrigerants, detergents, animal and vegetable oils, ketones and fats. However, it is less stable in aliphatic and aromatic solvents (such as gasoline, benzene, etc.) and mineral oil. Performance is also reduced under the long-term effect of concentrated acid.
Should have any question on the selection for Bonve Rotary Lobe Pump and Homogenizer mixer O-ring material, contact us to learn more.
