Chemical resistance is something to taken into account before choosing your type of elastomeric seal and your body/sensor material of your mass flow meter. How do you make the right choice?
Mass flow meters and controllers are designed to measure and control the flow of various gases and liquids. In many applications a general elastomeric seal, such as Viton® flouroelastomer, is used with no chemical compatibility issues.
Many customers never even think about their elastomeric seal options. However, there are also many applications where the gas or liquid is more aggressive and would cause chemical compatibility issues with a Viton® seal; issues such as elastomeric swelling or elastomeric breakdown.
There are other elastomeric seal choices available, such as:
The selection of elastomeric sealing material for mass flow meters must be based on chemical resistance at operating conditions. Bronkhorst has gathered a lot of information about the compatibility of various compounds and we can advise our customers accordingly.
Another area to be aware of for chemical resistance is the body and sensor material of the mass flow meter. Stainless steel is a common material used for the body and sensor, but applications with particularly aggressive chemicals may require a Hastelloy sensor, or a sensor coated for higher chemical resistance.
In conjunction with the advice from Bronkhorst, a useful website for helping you decide which elastomeric seal or sensor material are appropriate for your application is: the DuPont Chemical Resistance Guide.