Hermetically sealed and rustproof: The Protection product family PMCN is also available in a stainless steel design. This is or particular interest to the food and packaging industries. Their main special feature is the compact, totally sealed bellow between the body and the cap made of TPU (thermoplastic polyurethane). This protection safely encapsulates the ACE rolling diaphragm from the outside environment. Aggressive fluids don't stand a chance. The PMCN ramge is an excellent alternative if the accessory option of the SP type air bleed collar cannot be used due to a lack of compressed air.