The engine had a single rotary valve to control induction and exhaust.
This property can simplify the operating controls to a single valve throttling the turbine.
The operators can, of they have a mind to question the systems' automatic decisions, run through the status of the entire building or a single valve.
The single horizontal valve allowed the diatonic scale to be played by each bugle.
The single valves are preserved in a fine-grained limestone.
Both atria communicate with the ventricle by a single atrio-ventricular valve.
The long canvas hoses hooked directly into the Overlook's plumbing system, and by turning a single valve you could become a one-man fire department.
This is either in the form of a single solid valve or as a bi-metallic valve.
Early engines were incapable of this, as they used a single valve for both inlet and exhaust.
Multiple valves arranged to be triggered together are occasionally used as an alternative to a single larger valve.