15
Replacement of Cover Gasket for Padmount Switchgear Side-Hinge-2 Models
Field Service inStructionS
MN285009EN April 2019
Figure 68.
Sensitivity dial at 10
Figure 69.
Scanning for leaks
12.6.4 If the detector indicates a leak, decrease the
sensitivity to 3 (Figure 70) to help pinpoint
each location on the cover where a leak exists.
Figure 70.
Sensitivity dial at 3
12.6.5
When you find a leak:
Tighten three or four
cover-bolts in the area of the leak 1/4-turn at a
time, until the leak is no longer present.
12.6.6 Continue working your way around the unit as
described in step 12.6.3 through step 12.6.5
until you have located and stopped all leaks.
After you have found and stopped
all
leaks
,
continue to 12.6.7
12.6.7 Repeat the leak test:
a. Open the shut-off valve and repressurize
the tank to 7.25 psig; then close the shut-
off valve.
b. Let the tank sit for 30 minutes with the air
pressure at 7.25 psig; then check to see if
the pressure was maintained:
●
●
If the pressure dropped below
7 .25 psig:
The tank is still leaking.
Repeat step 12.6 as needed until the
tank passes the leak test.
●
●
If the tank maintained a pressure of
7 .25 psig
for the 30-minute test period,
the tank passed the leak test. In that
case, continue to step 12.7.
12.7
After the unit has passed the leak test:
12.7.1 Release the pressure to the tank.
12.7.2 Use a Makita BFL300FZ pre-set torque nut
runner set to 18 ft-lbs and Proto MC10568000
9/16-inch impact socket (or equivalent tools)
to tighten all bolts using the pattern shown in
Figure 71.
#2
#4
#3
#1
Figure 71.
Final tightening sequence
12.7.3 Remove the leak-test assembly (Figure 62)
from the tank and replace the pressure relief
valve.
12.7.4
For units with two pressure relief valves
(one per side): Remove the 1/4-inch NPT Pipe
Plug you installed for the test and replace the
second pressure relief valve.
