Abstract: A valve of the pilot type including a housing with a circular cylinder end for mounting in a valve base. The housing has an inlet port, an outlet port, an internal cavity, and a flexible membrane dividing the cavity into a flow chamber and control chamber. The inlet port is in constant communication with the flow chamber, while the outlet port is in communication with the flow chamber via a valve seat formed in the housing opposite the membrane. The outlet port is formed at the face of the cylinder end. An annular seal is disposed on that face, around the outlet port, such that when the valve is mounted into the valve base, the seal is urged axially to a face of the valve base providing fluid-tight communication between the outlet port and an outlet opening in the valve base. The inlet port is formed at the lateral surface of the cylinder end, so as to provide inlet flow transverse to the axis of the cylinder end.