The upper side of the shell has an opening, adapted to be closed by a cap C, large enough to insert the valve D, which is hinged to the upper side of the partition. Water or gas is forced in through the valve in the direction of the arrow, and the hinged valve is always in position to close the opening in the partition.
In case the valve should leak it may be readily ground by taking the small plug E from the opening, and with a screw driver, turning the valve, and thereby fit it snugly on its seat.
Gate Valve.—The cylindrical shell A has its ends internally threaded, and is provided, midway between its ends, with a partition wall B, having a central aperture. The upper side of the shell has an opening to receive the bonnet C, through which the valve stem D passes. This stem carries at its lower end a gate E which rests against the partition B.
The stem D is threaded to screw into the threaded bore of the gate. A packing gland F surrounds the stem D. It will thus be seen that the turning of the stem D draws the gate up or down, and thus effects an opening, which provides a direct passage for the water through the valve body.
Globe Valve.—A globe valve has the advantage that the valve is forced against its seat by the pressure of the wheel, differing from the gate valve, that depends on the pressure of the fluid to keep it tight.