2-18. OPERATING PROCEDURES.
The following paragraphs will describe operating procedures necessary for all firefighting missions for which the
following truck was designed. It is strongly recommended that all personnel required to operate the vehicle study
the contents of these procedures thoroughly and practice the safety precautions specified.
2-19. STAND-BY MODE PROCEDURES.
The following valves and gauges must by checked prior to placing the Twin Agent 4x4 Firefighting Truck in the
STAND-BY mode of operation.
a. Master control valve (5, figure 2-1) CLOSED. Manual twin agent pressure activator handle (3) pushed fully
b. Test valves (7, figure 2-1) OPEN.
c. Dry chemical tank drain cap (8, figure 2-1) and dry chemical tank fill cap (19) fully tightened.
d. Purge valve (17, figure 2-1) and bleed valve (18) CLOSED.
e. Dry chemical emergency shut-off valve (13, figure 2-1) OPEN.
f. AFFF tank drain valve (10, figure 2-1) CLOSED.
g. AFFF emergency shut-off valve (9, figure 2-1) OPEN.
h. Purge valve (16, figure 2-1) and bleed valve (14) CLOSED.
i. Dual agent handline control handles (22, figure 2-1) CLOSED.
j. Turret valves (3 and 13, figure 2-2) CLOSED.
k. Pressure gauges (1, figure 2-1) and (11, figure 2-2) should read ZERO.
1840 psi (12,686.8 kPa) is the minimum
cylinder pressure for a working pres-
sure of 230 psi (1,585.8 kPa). For in-
termediate working pressure, the
minimum cylinder pressure should
read 8 times the selected working
l. Open all nitrogen cylinder valves and check pressure gauges for cylinder pressure. Pressure gauge readings
should be in excess of 1840 psi (12, 686.8 kPa).
m. The system is now ready for operation.