(_With The Deane Switch Valve._)
The application of this valve is shown in Fig. 307, on the opposite
page. It can be attached to any regular Compound or Triple Expansion
Pump, and if not in use does not in any way impede the regular running
of the machine.
The Deane switch valve is a device by which compound low service pumps
may be converted into powerful fire pumps. This appliance consists of
a valve of such construction that steam may be allowed to enter the
cylinders as usual for compounding, or may be diverted by simply moving
a lever, when all four cylinders receive steam at boiler pressure, each
exhausting independently to the atmosphere. The change makes each steam
cylinder available for its maximum power, all four cylinders develop
their full power, and its effect can be utilized in powerful fire
streams.
It should be borne in mind in justice to the manufacturers that
the Deane switch valve is not to be classed with the ordinary two
or four-valve arrangement, which, while admitting initial steam to
the second cylinders, develops no power in the first, or, as it
is sometimes arranged, uses initial steam in all four cylinders
and develops less power than if the second cylinders were used
independently.
This valve is recommended by the Insurance companies, and compound
duplex pumps fitted with the Deane switch valve will be accepted in
place of the Underwriter pump of similar capacity. This valve is also
frequently used where two widely differing water pressures are required
for other purposes than for fire protection.
Every machine is subject to rigorous tests before leaving the factory,
including a 300-pound test of the water cylinders. Every pump is
guaranteed to be in full accordance with the specifications.