Pressure compensation valve

A valve assembly for a valve, comprising:

• a valve body having walls defining a valve chamber;
• a first fluid port;
• a second fluid port;
• a valve seat located between the first and second fluid ports;
• a moveable member comprising:
• a valve element at its first end,
• an armature at its second end, and
• a shaft portion extending axially between the valve element and the armature,
• wherein the moveable member is moveable in an axial direction to bring the valve element into and out of engagement with the valve seat to selectively open and close the valve and wherein the entire moveable member is spaced from the walls of the valve body when the valve is open or partially open;
• at least one biasing member configured to support and bias the moveable member in the axial direction;
• and
• a flexible membrane which forms a seal against the moveable member and the valve body to divide the valve chamber into a flow chamber in which the valve seat and valve element are located and a pressure compensation chamber within which the armature is entirely enclosed,
• wherein the moveable member comprises one or more bores defining a pressure compensation flow path by which the first fluid port is fluidly connected to the pressure compensation chamber, the pressure compensation flow path having at least one opening extending into the pressure compensation chamber at an axial position between the armature and the flexible membrane,
• wherein the pressure compensation flow path comprises:
• a first axial portion with a first length and a first cross-sectional area;
• and
• a second axial portion adjacent to the first axial portion with a second length and a second cross-sectional area which is less than the first cross-sectional area,
• wherein the first length is at least 20 percent of the second length;
• wherein the valve element comprises a first axial bore and the shaft portion comprises a second axial bore, wherein the first axial portion of the pressure compensation flow path is defined by the first axial bore and the second axial portion of the pressure compensation flow path is defined by the second axial bore, the shaft portion and the valve element being discrete components which are fixed together with an interference fit.