Failure of diaphragm fitted to fuel excess pressure regulating valve actuator
Lloyd's Register Safety Alert In its Classification News No.12/2012, Lloyd's Register has issued a safety warning telling of a failure of the diaphragm fitted to the fuel excess pressure regulating valve actuator. The alert reads as follows:"Following an engine room fire on board a Lloyd's Register classed vessel (in way of the auxiliary engines), the Marine Accident Investigation Branch (MAIB) concluded that the diaphragm fitted to the fuel excess pressure regulating valve actuator failed, resulting in pressurised fuel leaking onto an exposed high-temperature surface.Examination of the failed diaphragm revealed signs of excessive wear, creasing and some delamination of the rubber. There were also signs of tearing of the reinforcing fabric layer.The actuator diaphragm in the excess pressure regulating valve perished and ruptured as a result of prolonged exposure to marine fuel oils. The diaphragm rubber was made from ethylene propylene diene monomer (EPDM) M-type synthetic rubber, which is unsuitable for use with oils.The standard Samson excess pressure regulating valve 2413 is supplied with a single EDPM diaphragm. Samson also provides oil-resistant fluorocarbon rubber (FPM) rubber diaphragms.Lloyd's Register recommendationLloyd's Register recommends that operators should verify that the diaphragms fitted to pressure regulating valve actuators used on fuel oil systems are checked ...
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