A valve has a housing and a component movable within the housing. The housing has first, second and third ports formed in it. The movable component has a first passageway formed in it. Movement of the movable component within the housing selectively connects the first port through the first passageway to the second port, or the second port through the first passageway to the third port. At least one of the first and second ports includes a first member for contacting the movable valve component and a second member for retaining the first member. The second member may be constructed from a semiconductive material. At least a region of the movable component around a first end of the first passageway may be semiconductive. |