Diaphragm life not only depends on a diaphragm’s chemical compatibility with the process fluid, but also on the process conditions. These conditions will vary depending on the abrasiveness of the process fluid, temperature, size of diaphragm, pumping media and lift conditions. Contact Integrity Pumps & Engineering in regards to which Wilden diaphragm material will work best for particular application requirements.
Integrity Pumps and Engineering use a “general” rule (ratings) for the use of chemicals through Wilden diaphragms. Neoprene or Wilflex Wilden diaphragms should generally be used unless the chemical is deemed unsatisfactory. Even though Buna, Nordel or Viton Wilden diaphragms show “A” ratings, if Neoprene or Wilflex Wilden diaphragms have at least a “B” rating, it will probably be the most economical choice.
Viton Wilden diaphragms are six times (6x) the replacement cost of neoprene diaphragms. Viton diaphragms should only be considered for aggressive media at extreme temperatures and if Neoprene, Buna and Nordel show an unsatisfactory rating.
The above guides for the best Wilden diaphragm selection do not hold for the valve ball material. Because the Wilden diaphragms are securely gripped by their inner and outer beads, they can stand up to 20% swell without affecting pump performance.
If the valve balls swell even a very small amount, they cannot function properly. There will be instances where Neoprene Wilden diaphragms will be the best selection but Teflon, Buna, Nordel or Polypropylene balls will be required.