Extra support land for valve disc

摘要

A valve for controlling fluid flow through a passage defined by a valve body or a piston includes a valve disc which abuts the valve body or the piston. The valve body or the piston defines a first supporting member for the valve disc, a second supporting member for the valve disc located radially inward from the first supporting member and a third supporting member for the valve disc located between the first and second supporting members. This valve disc abuts the first and second supporting members and a clearance is defined between the valve disc and the third supporting member.