TM5-42 1 0-229-14&P
2-23. SYSTEM SHUT-DOWN AFTER OPERATION PROCEDURES (Continued).
d. Select AFFF mode in remote turret using AFFF/DC selector switch (10, figure 2-2) and press twin agent acti-
vating button (2) until only nitrogen discharges from the turret foam nozzle.
e. Select Dry Chemical mode in remote turret using AFFF/DC selector switch (10, figure 2-2) and press twin
agent activating button (2) until only nitrogen discharges from the turret dry chemical nozzle.
f. CLOSE test valves (7, figure 2-1).
g. CLOSE master control valve (5, figure 2 -1) by using either manual twin agent pressure activator handline (3)
or remote turret pressure activator switch (9, figure 2-2).
h. OPEN the bleed valves (14 and 18, figure 2-1).
i. CLOSE all nitrogen cylinder valves if nitrogen pressure in the cylinders has dropped below 1840 psi (12, 686.8
kPa), so that the cylinders may be changed.
If use has only been minimal and cylinder
pressure is in excess of 1840 psi (12,686.8
kPa), then omit step i above. The system
is ready for the next operation.
j. CLOSE the purge valves (16 and 17, figure 2-1).
k. OPEN the AFFF emergency shut-off valve (9, figure 2-1) and the dry chemical emergency shut-off valve (13).
l. CLOSE the bleed valves (14 and 18, figure 2-1).
m. The system is now shut-down and ready for nitrogen cylinder change.
2-24. AFFF VESSEL RECHARGE PROCEDURES.
a. CLOSE all nitrogen cylinder valves.
b. CLOSE test valves (7, figure 2-1).
c. Check that the master control valve (5, figure 2-1) is CLOSED.
d. OPEN purge valve (16, figure 2-1) and bleed valve (14) to bleed any trapped pressure out of the vessel.
e. OPEN AFFF handline slowly and leave OPEN.
If there is any trapped pressure in the vessel its presence
will be apparent from hissing gas escaping from the safety
hole in the AFFF Tank fill cap (15, figure 2-1). Do not
Ioosen cap until there is no further gas escaping.