A pressure compensation device for compensating an internal pressure in a housing of an electrochemical device includes: at least one gas-permeable membrane for gas exchange between an interior of the housing and surroundings of the electrochemical device; and a valve body that can be transferred from a home position resting on a valve seat into a use position remote from the valve seat, the valve body including a gas throughflow opening that is sealed by the gas-permeable membrane.

A compressor lubrication system including a positive displacement pump, a pressure relief valve assembly, and a divider block. The pressure relief valve assembly includes a housing that has an opening to the fluid distribution system and a relief passage. A conduit is connected from the relief passage to a fluid reservoir. The assembly also includes a pressure relief valve that has an open position in which fluid from the fluid distribution system can enter the relief passage, and a closed position in which fluid is prevented from entering the relief passage. A biasing element maintains a biasing force on the pressure relief valve. The pressure relief valve is maintained in the closed position when the biasing force exceeds the fluid force on the pressure relief valve and the pressure relief valve moves into the open position when the fluid force exceeds the biasing force.

A compressor lubrication system including a positive displacement pump, a pressure relief valve assembly, and a divider block. The pressure relief valve assembly includes a housing that has an opening to the fluid distribution system and a relief passage. A conduit is connected from the relief passage to a fluid reservoir. The assembly also includes a pressure relief valve that has an open position in which fluid from the fluid distribution system can enter the relief passage, and a closed position in which fluid is prevented from entering the relief passage. A biasing element maintains a biasing force on the pressure relief valve. The pressure relief valve is maintained in the closed position when the biasing force exceeds the fluid force on the pressure relief valve and the pressure relief valve moves into the open position when the fluid force exceeds the biasing force.

A high pressure pump includes a pressurization portion, a discharge portion, a body portion, a valve member, an urging member, valve hold member and a limiting portion. The body portion includes a relief passage, an inlet, a valve seat, and an outlet. The valve member includes a large diameter portion and a small diameter portion. The small diameter portion is located between the valve seat and the large diameter portion and has an outer diameter smaller than an outer diameter of the large diameter portion. The valve hold member surrounding and holding the large diameter portion. The limiting portion capable of limiting a motion of the valve hold member in a separation direction. According to this, a pressure in a fuel rail from extraordinarily increasing again after the relief valve is opened once.