-
19-
While the operation of this pump is similar to earlier models, there are some new
innovations as well as required accessories that should be discussed. The following is a
list of these items.
SUCTION RELIEF VALVE:
N.F.P.A. STANDARD 1901 requires that all
new pumpers be equipped with an automatic
intake pressure relief system. This system
helps protect the intake side of the pump
from excessive pressures, as may be
encountered when working from a wall
hydrant or during an in-line operation. Each
of the four suction inlets to the pump are
equipped with an intake relief valve as shown
in
Figure 16
. With an operating range of
75-250 PSI, the intake relief valves on this
apparatus are adjusted to open at 125 PSI.
SELF-BLEEDING DRAINS:
The two cross-lay beds and the deck gun are equipped with self bleeding drains which
open automatically when the pressure on these discharges drops below 5 PSI.
AIR BLOWOUT SYSTEM:
The pump is equipped with an air blowout
system which will help to drain the entire
pump of water. This will be especially useful
during cold weather. The instruction plate is
found at the upper right portion of the pump
operator’s panel as shown in
Figure 17
.
SLOW CLOSE DEVICES:
N.F.P.A. STANDARD 1901 dictates that all intakes/discharges 3" or larger be equipped
with slow open/close devices to reduce the likelihood of water hammer when these
valves are operated. Therefore, front and rear intakes are so equipped with the air
operated intake valves mention earlier.
