A high pressure container system is equipped with an upstream side pressure sensor that measures an internal pressure of high pressure containers upstream of a pressure regulating valve, a plurality of downstream side pressure sensors that measure the pressure of the fluid downstream of the pressure regulating valve, and a control device. At a normal time of the downstream side pressure sensors, a control device monitors the internal pressure of the high pressure containers on the basis of the measured values of the downstream side pressure sensors, and at an abnormal time when any one of the downstream side pressure sensors is abnormal, the control device monitors the internal pressure of the high pressure containers on the basis of the measured values of the downstream side pressure sensors, and the measured value of the upstream side pressure sensor.

A high pressure container system is equipped with an upstream side pressure sensor that measures an internal pressure of high pressure containers upstream of a pressure regulating valve, a plurality of downstream side pressure sensors that measure the pressure of the fluid downstream of the pressure regulating valve, and a control device. At a normal time of the downstream side pressure sensors, a control device monitors the internal pressure of the high pressure containers on the basis of the measured values of the downstream side pressure sensors, and at an abnormal time when any one of the downstream side pressure sensors is abnormal, the control device monitors the internal pressure of the high pressure containers on the basis of the measured values of the downstream side pressure sensors, and the measured value of the upstream side pressure sensor.

A PRV is provided, comprising an inlet, an outlet, and a pressure regulating system therebetween to maintain a set pressure at the outlet. The PRV further comprises a selection system configured to select between the two working pressures based on the pressure of the fluid at the inlet of the PRV, and to direct the pressure regulating system to maintain the set pressure at the outlet at the selected working pressure. The selection system comprises a pressure-motion transducer for directing the set pressure when in pressure communication with the inlet, and an auxiliary valve having an auxiliary inlet in pressure communication with the inlet and an auxiliary outlet in pressure communication with the pressure-motion transducer. The auxiliary valve is configured to establish pressure communication between its inlet and outlet when pressure in the inlet traverses a predetermined threshold.

A PRV is provided, comprising an inlet, an outlet, and a pressure regulating system therebetween to maintain a set pressure at the outlet. The PRV further comprises a selection system configured to select between the two working pressures based on the pressure of the fluid at the inlet of the PRV, and to direct the pressure regulating system to maintain the set pressure at the outlet at the selected working pressure. The selection system comprises a pressure-motion transducer for directing the set pressure when in pressure communication with the inlet, and an auxiliary valve having an auxiliary inlet in pressure communication with the inlet and an auxiliary outlet in pressure communication with the pressure-motion transducer. The auxiliary valve is configured to establish pressure communication between its inlet and outlet when pressure in the inlet traverses a predetermined threshold.

A vehicle control device for a vehicle, the vehicle including a rotation lock mechanism preventing rotation of a coupling portion on the engine side of the rotating member in at least one direction, and an engine rotation speed sensor detecting a rotation speed of the engine, includes: a characteristic detecting portion detecting at least a torsional rigidity as the rotational characteristic by applying a torque to the rotating member from the electric motor to measure a twist angle of the rotating member while the rotation of the coupling portion is prevented by the rotation lock mechanism; and an engine rotation filtering portion calculating an actual resonance frequency based on the torsional rigidity detected by the characteristic detecting portion and filtering an engine rotation speed signal supplied from the engine rotation speed sensor to attenuate a vibration component of the actual resonance frequency in the engine rotation speed signal.

Apparatus and methods for reducing pressure exchanger manifold resonance. Example apparatus include a first manifold and pumps fluidly connected with the first manifold. Each pump is operable to inject a pressurized clean fluid into the first manifold. The apparatus may further include a second manifold and pressure exchangers each fluidly connected with the first and second manifolds. Each pressure exchanger is operable to receive the pressurized clean fluid from the first manifold and discharge the pressurized dirty fluid into the second manifold. The apparatus may also include a first flow restricting orifice fluidly connected along the first manifold, a second flow restricting orifice fluidly connected along the second manifold, and a discharge conduit fluidly connected with the wellbore to permit the pressurized dirty fluid to be injected into the wellbore during a well treatment operation.

Apparatus and methods for reducing pressure exchanger manifold resonance. Example apparatus include a first manifold and pumps fluidly connected with the first manifold. Each pump is operable to inject a pressurized clean fluid into the first manifold. The apparatus may further include a second manifold and pressure exchangers each fluidly connected with the first and second manifolds. Each pressure exchanger is operable to receive the pressurized clean fluid from the first manifold and discharge the pressurized dirty fluid into the second manifold. The apparatus may also include a first flow restricting orifice fluidly connected along the first manifold, a second flow restricting orifice fluidly connected along the second manifold, and a discharge conduit fluidly connected with the wellbore to permit the pressurized dirty fluid to be injected into the wellbore during a well treatment operation.

A method of reducing hydraulic shock in a BOP system including a pressure regulator having an input port and an output port, and a regulator piston that moves between an open and a closed position based on a change in hydraulic pressure applied to the regulator piston via a pilot port. The method includes initiating a function, and monitoring the state of the function as it is carried out to predict when the function nears the end of its cycle. The method also includes, when the function reaches a predetermined state, adjusting the hydraulic pressure on the regulator piston via the pilot port to gradually move the regulator piston between the open to the closed position to reduce fluid flow through the fluid path in a controlled manner to reduce hydraulic shock.

A method of reducing hydraulic shock in a BOP system including a pressure regulator having an input port and an output port, and a regulator piston that moves between an open and a closed position based on a change in hydraulic pressure applied to the regulator piston via a pilot port. The method includes initiating a function, and monitoring the state of the function as it is carried out to predict when the function nears the end of its cycle. The method also includes, when the function reaches a predetermined state, adjusting the hydraulic pressure on the regulator piston via the pilot port to gradually move the regulator piston between the open to the closed position to reduce fluid flow through the fluid path in a controlled manner to reduce hydraulic shock.

A choke for fluid connection between a manifold and a pump. The choke includes a fluid passage having an inlet, a contraction portion, a throat, an expansion portion, and an outlet. The inlet has a first diameter and the outlet has a second diameter. The throat is substantially cylindrical, having a third diameter that is substantially less than the first and second diameters. The contraction portion connects the inlet and the throat and gradually decreases from the first diameter to the third diameter along a longitudinal axis of the fluid passage. The expansion portion connects the throat and the outlet and includes a substantially cylindrical chamber having the second diameter.