An isolation mechanism for isolating a submerged pump in a storage vessel, where the isolation mechanism comprises a primary valve member and a secondary valve member, which are both biased in a fail-closed position. The isolation mechanism allows for redundancy for safety and reliability, and can be operated externally of the storage vessel. Furthermore, the isolation mechanism comprises venting and purging devices for safe operation of removal and installation of the pump in the storage vessel.

An estimation unit estimates a fuel pressure on a discharge side of a high-pressure pump based on an amount of fuel injection with a fuel injection valve from a time point at which a detected fuel pressure changes from a higher status than a first pressure to a lower status, assuming that the fuel has not been discharged with the high-pressure pump. The determination unit determines that a relief valve is in an open status based on a dropping mode of the estimated fuel pressure and a dropping mode of the detected fuel pressure.

In a fuel supply device including a regulator and float-type level sensor, a fitting tube is formed integrally with an upper housing, a fuel pump being retained between the upper and lower housings. An outer periphery of a base part of the regulator is fitted into the tube. A regulator retaining member is formed as a separate member from the upper housing and retains the regulator in cooperation with the tube. The tube and the retaining member are joined via a snap-fit join part provided on fitting parts therebetween. The snap-fit join part is formed by engaging a projecting portion or a recess part, formed on an elastic piece provided on one of the fitting parts between the retaining member and the tube, with the recess part or the projecting portion formed on the other fitting part. A sensor support arm is molded as a unit with the retaining member.

A pressure relief valve includes a valve body with a hollow internal cavity. The internal cavity has two opposite ends, which are in communication with a high-pressure side and a low-pressure side of the pressure relief valve respectively. The pressure relief valve further includes a separating plate disposed in the valve body and located in the hollow internal cavity, and a penetrating member configured to slide linearly in the valve body. The penetrating member has a force applied thereto from the low-pressure side towards the high-pressure side by an elastic component located in the internal cavity. The pressure relief valve further includes a locking structure disposed in the valve body in a fixed manner and spaced apart from the separating plate. The penetrating member is locked in a cut-off state of the pressure relief valve by the locking structure.

An object of the invention is to provide a fuel supply pump that can simultaneously prevent cavitation erosion in a relief valve seat portion at the time of increasing the pressure and reduce a maximum pressure when releasing an abnormally high pressure. Therefore, in the fuel supply pump, a relief valve mechanism includes a seat portion and a relief valve seated on the seat portion, and sets a set discharge pressure to 30 MPa or more. A seat angle of the seat portion is formed to be 40° to 50°, and a set valve opening pressure of the relief valve mechanism is set to 2 MPa or more than the set discharge pressure.

A combination outlet valve and pressure relief valve includes an outer housing having a passage. An inner housing is located within the passage and includes a first bore extending thereinto from one end and a second bore extending thereinto from the other end such that the first bore and the second bore terminate at an inner housing wall. An outlet valve assembly is located within the first bore and includes an outlet valve member, an outlet valve seat, and an outlet valve spring grounded to the inner housing wall and biasing the outlet valve member toward the outlet valve seat. A pressure relief valve assembly is located within the second bore and includes a pressure relief valve member, a pressure relief valve seat, and a pressure relief valve spring grounded to the inner housing wall and biasing the pressure relief valve member toward the pressure relief valve seat.

A high pressure fuel pump is provided with a pumping bore and a pressure relief valve only opening to enable a return flow from the outlet conduit back to the compression chamber when the pressure in the outlet conduit exceeds a predetermined threshold. The pressure relief valve is arranged in an elongated pressure relief valve chamber extending parallel and offset to the pumping bore.

A method for monitoring a pressure sensor in a direct injection system including at least one common rail, a high-pressure fuel pump, a hydraulic circuit connecting the high-pressure pump to the common rail, a passive pressure-limiting valve connected to the hydraulic circuit, configured to open once the pressure in the hydraulic circuit is greater than a threshold pressure, so as to discharge the fuel, including the steps of detecting the opening of the pressure-limiting valve, measuring the pressure P.sub.MES corresponding to the time of opening of the pressure-limiting valve and comparing the measured pressure P.sub.MES to the threshold pressure P.sub.1 in order to detect a drift in the pressure sensor.

A system and method for reversing a movement direction of a laterally extending conveyor of a draper header of an agricultural machine. The system includes a fluid line for delivering fluid to a motor that drives the laterally extending conveyor. A directional flow control valve is connected to the fluid line and is movable between a first state in which the directional flow control valve is configured to deliver the fluid to the motor in a first fluid direction to cause the motor to move the laterally extending conveyor in a first movement direction, and a second state in which the directional flow control valve is configured to deliver the fluid to the motor in a second fluid direction that is different from the first fluid direction to cause the motor to move the laterally extending conveyor in a second movement direction that is opposite to the first movement direction.

To increase a valve-opening pressure at which a pressure relief valve is opened in order to deal with a higher pressure of the fuel, a large pressure relief valve is installed in a high-pressure fuel supply pump. This upsizes the high-pressure fuel supply pump. A pressure relief valve is installed in a discharge joint. This can provide a high-pressure fuel supply pump that is not large too much and sufficiently performs a relief function by efficiently using the excessive space in the pump even when the fuel pressure is increased.