F
IRE
F
LEX
®
N
2
B
LAST
®
Integrated Fire Protection System
O
WNER
'
S
O
PERATION
&
M
AINTENANCE
M
ANUAL
Page 20 of25
FM-076B-0-6A
5.4.2 Air supply Style "B"
See figure 5.4.
The Viking model D-2 air pressure maintenance device
(APMD)
(E5)
is a pressure regulator that automatically
reduces the supply air pressure to a pre-set requirement
when connected to a constantly maintained air supply
(plant air, external tanked air compressor or dry nitrogen
tank).
Features:
•
Replaceable air inlet filter
•
Outlet pressure range is 5 to 75 psi (
±
2 psi) (0.345
to 5.17 bar). Air pressure setting can be readjusted
after installation (refer to chapter 5.3.2 TO ADJUST
SYSTEM AIR PRESSURE for air supply Style "B").
•
Ball check to prevent back flow
•
Restriction orifice 1/16" (1,59mm) to prevent rapid
re- pressurization of a system. The Viking model D-
2 APMD
(E5)
regulates and restricts air flow.
•
The air or nitrogen supply provided to the
APMD
(E5)
must be continuous, clean, dry and oil
free.
•
Bypass piping is provided to allow initial
pressurization of system piping more rapidly than
the restricted air flow through the APMD
(E5)
will
allow.
•
Determine the appropriate pressure to be
maintained in the system (refer to table 5).
The APMD
(E5)
should be checked after installation or
repair and adjusted as required for correct pressure
reading (refer to chapter 5.3.2 TO ADJUST SYSTEM AIR
PRESSURE). The filter should also be inspected and
replaced or cleaned as required.
To clean the APMD (E5):
1.
This procedure requires turning OFF the
compressor's power.
2. Do not disconnect or disassemble the APMD
(E5)
without closing the outlet
(E7)
and inlet
(E6)
isolation
valves. System air pressure will be trapped between
the outlet of the APMD
(E5)
and the downstream
control valve. Relieve pressure before proceeding
with disassembly.
3. Carefully loosen the union between the outlet of
APMD
(E5)
and the outlet isolation valve
(E7)
to
relieve pressure.
4. Remove and clean APMD
(E5)
filter. If admission
filter is blocked, replace with filter kit (part # 03007
A).
Refer to Viking Technical Data Sheet #127 for additional
details.
To close the air supply:
Close APMD
(E5)
output isolation valve
(E7)
by placing
handle crossways to the valve body. Make sure the
APMD
(E5)
input valve
(E6)
is open (handle in line with
valve body) and the bypass valve
(E8)
is closed (handle
crossways to valve body).
