Compatibility note: elastomer selection for DG Series diaphragm pumps

PTFE diaphragms are chemically near-universal and are the default specification on the DG-50 and DG-80. EPDM, fitted to the DG-52, is materially cheaper and has better flex life, but it is attacked by mineral oils, aromatic and chlorinated hydrocarbons, and concentrated oxidising acids. EPDM is entirely appropriate for water, dilute caustic, alcohols and most aqueous process streams.

The DG-52 is hydraulically equivalent to the DG-50 and shares its body, connections and footprint. The substitution is a pure elastomer change. It must not be made on the strength of the part number alone: the actual pumped media has to be named and checked against the EPDM compatibility table before the substitution is offered. Where the media is unknown or the customer's process is mixed-service, quote the DG-50 with PTFE.