The first of these changes occurred in 1998 when a removable valve system was added to the cap to facilitate cleaning.

This valve system has become a trademark feature of Ducati motorcycles.

It was restored into full operational status sometime in 2005 and retains the original valve system.

It would surge up the shaft and then find itself guided by the valve system, just below the turbines.

An intricate valve system prevented any backing up of the flow.

Most control valve systems in the past were implemented using mechanical systems or solid state electronics.

The Pegasus introduced in 1956 was their most popular valve (vacuum tube) system, with 38 units sold.

The key to the Vauclain compound is its valve system.

Made mostly from stainless steel, the valve system was the first to incorporate a pressure regulator directly into the marker.

Rover used the same valve system on its models in the 1950s.