1.6 Oil fuel transfer Overflow pipes and relief valves not in closed e circuit must discharge to an overflow tank having an alarm device, the discharge being visible Tank air pipes must have 25% more area than their filling pipes and should have their outlets situated clear of fire risks They should also be fitted with detachable wire gauze diaphragms Provision should be made for stopping oil fuel pumps from outside the machinery spaces1.6 Oil fuel transfer • Overflow pipes and relief valves not in closed circuit must discharge to an overflow tank having an alarm device, the discharge being visible. • Tank air pipes must have 25% more area than their filling pipes and should have their outlets situated clear of fire risks. • They should also be fitted with detachable wire gauze diaphragms. • Provision should be made for stopping oil fuel pumps from outside the machinery spaces