Abstract: A pressure regulator is disclosed having a body, a valve seat dividing a cavity of the body into first and second portions, and an end stop movable against a bias to selectively engage the valve seat and isolate the first and second portions. The pressure regulator may also have a first inlet port in the first portion, a first outlet port in the second portion and in fluid communication with the first portion via the valve seat, and a second inlet port in the second portion. The fuel system may also have a valve element in the second portion and movable against a spring bias based on a pressure difference between an open position and a restricted position against the end stop. The fuel system may additionally have an actuator biased to urge the valve element toward the second position and selectively actuated to move away from the valve element.

Abstract: A method of operating an engine is disclosed. The method includes estimating an operational status of a cryogenic pump selectively driven by the engine. The cryogenic pump is configured to pressurize a liquefied gaseous fuel. The method also includes estimating a power requirement of the cryogenic pump. The method further includes determining whether the engine is operating on a lug curve. Moreover, the method includes providing additional fuel to the engine in order to increase an engine power beyond the lug curve prior to an operation of the cryogenic pump. The increase in engine power is at least equal to the power requirement of the cryogenic pump.

Abstract: A pressure regulator is disclosed having a body, a valve seat dividing a cavity of the body into first and second portions, and an end stop movable against a bias to selectively engage the valve seat and isolate the first and second portions. The pressure regulator may also have a first inlet port in the first portion, a first outlet port in the second portion and in fluid communication with the first portion via the valve seat, and a second inlet port in the second portion. The fuel system may also have a valve element in the second portion and movable against a spring bias based on a pressure difference between an open position and a restricted position against the end stop. The fuel system may additionally have an actuator biased to urge the valve element toward the second position and selectively actuated to move away from the valve element.

Abstract: A pressure regulator is disclosed for use with a dual fuel engine. The pressure regulator may have a body, a cavity formed in the body, a first inlet port in fluid communication with a first end of the cavity, a first outlet port in fluid communication with the first end of the cavity, and a second inlet port in fluid communication with a second end of the cavity. The pressure regulator may also have a valve element movable based on a pressure difference between the first and second inlet ports to any position between a first fully open position at which fluid is allowed to flow from the first inlet port through the first outlet port substantially unrestricted by the valve element, to a second fully restricted position at which fluid flow from the first inlet through the first outlet port is blocked.