Speed control was either automatic, using a governor, or by a manual valve.

The collector should also allow for manual draining by closing the isolation valves (located above the storage tank) and opening the drain valves.

One is constant flow; the other is a manual on-off valve called a bypass valve; both feed into the same hose which feeds the counterlung.

If you don't have them, use manual valves to adjust the radiators or turn them off in rooms not in use.

Backflow prevention must be automatic, and so manual valves are not usually acceptable.

Each gas cell had a spring-loaded relief valve and manual valves operated from the control car.

Patch anything you can patch, and use the manual valves to shut off everything else.

In some instances, it is not automated at all and involves little more than a connection to the plant vacuum system, a few manual valves, and a gauge.

Stems are either smooth for actuator controlled valves or threaded for manual valves.