Pressure equalizing valve

A pressure equalizing valve, comprising:

• a valve body with first and second end faces, said body having a longitudinally disposed bore therein, an inlet port for receiving a first pressurized fluid therethrough, an outlet port for transporting said first fluid downstream of said valve, a by-pass outlet port for transporting said first fluid away from said outlet port, a first sense port disposed in said first end face for sensing the pressure of said first fluid downstream of said valve, a second sense port disposed in said second end face for sensing the pressure of a source of a second pressurized fluid to be mixed with said first fluid downstream of said valve, said ports in fluid communication with said bore;
• spool means longitudinally disposed within said bore, said spool means formed with first and second piston means having first and second faces, respectively, said spool means freely translateable within said bore in response to a pressure differential between fluids at said first and second sense ports so as to allow said piston means to regulate the flow of said first fluid through said outlet and by-pass ports such that said first and second fluids maintain substantially equal pressures downstream of said valve;
• and
• first and second sealing means disposed proximate said first and second faces of said piston means, respectively, for sealing said inlet port , said outlet port , and said by-pass port from fluid communication with said first and second sense ports .