A valve includes a valve stem having a shaft and including first and second poppet members with a seal portion extending radially outward from the shaft and disposed on the shaft between the poppet members. The valve further includes a valve body having a valve bore within which the valve stem is disposed for reciprocating axial movement and includes first and second ports that defining passageways through which gas or liquid may flow into or out of the valve bore. The valve body further includes first and second valve seats against which the first and second poppet members selectively seal with the seal portion being in sealing engagement with the valve bore between the ports.