Principles of naval engineering - Historic Naval Ships Association

PRINCIPLES OF NAVAL ENGINEERINGDOMELOADINGCHAMBERSEPARATIONPLATEORIFICEDOMESEPARATINGPLATEDIAPHRAGMPLATEPLUG{FOR EXTERNALCHARGING)DOMENEEDLEVALVEDIAPHRAGMCHARGINGCONNECTIONRELIEFVALVEPRESSUREEQUALIZINGORIFICEDIAPHRAGMPLATESPRINGACTUATINGCHAMBEROUTLETBODYNEEDLEVALVEVALVESEATVALVEVALVESPRINGCAGEFigure47.6014-21.— Pneumatic pressure controlled reducing valve for low temperature servicediaphragm. This action forces the reverse-actingvalve off its seat. The pressure enteringthe regulator is then permitted to flow throughthe open valve into the reduced pressure line.A large pressure equalizing orifice transmitsthis pressure directly to the underside of thediaphragm. When the delivered pressure approximatesthe loading pressure in the dome,and the unbalanced forces are equalized, thevalve is closed. With the slightest drop indelivered pressure, the pressure charge in thedome instantly forces the valve open, thus allowingair to pass through the valve and maintain theoutlet pressure relatively constant.The pneumatic pressure controlled reducingvalve for high temperature service (fig, 14-22)operates in much the same way as the valve forlow temperature service, except that the valvefor high temperature service.is designed in sucha way as to keep heat from the hot fluid from affectingthe gas in the loading chamber. The380