... Class F or B, Protection IP54,Continuous duty. 2WB (Twin impeller) series stainless steel centrifugal pumps, produced by advanced ... or SUS316, with features of exchangeable components, stable quality, small size, light weight, corrosion resisting, high efficiency, long working life ... mechanical Seal: NBR/Ceramic/Carbon (other materials optional) Twin Impeller Stainless Steel Centrifugal Pump