American-Marsh Shows New Pump
At the New Orleans convention of the International Association of Fire Chiefs, the American-Marsh Pumps, Inc., of Battle Creek, Mich., had on display their new Barton-American midship fire pump. The pump is classed as a duplex, multistage pump.
The name “Duplex,” used in connection with this new design, refers to the application of two independent pumps; one designed for high capacity service and one for high pressure service, both pumps driven from one transmission and each provided with independent driving mechanism. The name “Multistage” applies to this unit in that both pumps may be operated at the same time and in series.
The design provides for a common suction and a common discharge with hose connections on either side of the chassis on which the pump may be mounted. Between the two pumps and in connection with the suction and discharge manifolds are located pressureoperated valves, all of which are automatic in operation.
Within the gear transmission, case to which both pumps are attached, is located a series of gears so arranged to provide an independent drive to each of the two independent pumps, and means, whereby, both pumps may be operated at the same time and in series. A single lever is arranged to shift the gears to their respective pumping positions and to position to drive the truck.
When operating the capacity pump, gears are shifted to drive this pump only. A small portion of its discharge is directed through the pressure pump (standing idle) and then to the discharge manifold; thus the idle pump is kept primed and ready for service, and danger of freezing is avoided.
When operating the pressure pump, gears are shifted to drive this pump only, and when in operation a portion of the incoming water passes through the low pressure pump, keeping it primed and ready for service and free from danger of freezing.
When operating in series, the low pressure pump delivers directly to the suction side of the pressure pump.
When operating from booster tank with the high pressure pump, automatic valve control permits removing suction caps and attaching suction hose. After suction is attached either pump may then be operated single stage or both pumps in series.