Pacer's S series self-priming centrifugal pumps are lightweight and chemically-resistant for general service on water, salt water, waste water, mild acids and bases. This is our most popular pump across multiple markets. They feature stainless steel internal fasteners, Viton®, EPDM or Buna O-rings with stainless steel external fasteners. There is a non-metallic option which minimizes solution contact with internal metal parts. The pumps are molded of tough, glass reinforced polyester, polypropylene or Ryton®. Polyester models are available with or without lined volute for abrasion resistance. All pumps include a built-in check valve, feature easy servicing and during pumping, a self-cleaning double volute keeps pump free of settled solids.