Table 2-1. Street Side Operator's Controls and Indicators - continued

TM 5-4210-224-14&P

Table 2-1. Street Side Operator's Controls and Indicators

250 GPM Mini-Pumper Firefighting Truck (Continued)

(Refer to Figure 2-1)

Key

Control or Indicator

Function

12.

Pressure Relief Control

The Pressure Relief Control Knob

Knob.

is used to increase or decrease the desired pump operating pressure.

The relief valve functions to prevent excessive build-up of pump

pressure when a hose line is shut-off, by automatically bypassing the

extra water from the discharge side to the suction side of the pump. The

relief valve is capable of controlling pump pressure from 0 to 300 PSI.

Turning the pressure relief control knob to the left (counterclockwise)

decreases pump pressure. Turning it to the right (clockwise) increases

pump pressure.

13.

Tank-To-Pump Valve

The Tank-To-Pump Valve Control

Control Handle.

Handle is used to allow water to flow from the water tank to the pump.

To operate, pull the handle all the way out, allowing the water to flow

from the tank.

Push the handle in to close.

2-6