Groth 3000 Series - Manual (Page 12)

9
PREVENTIVE MAINTENANCE
Periodically, while in service, examine the regulator
for leakage at bolted connection, adjusting screws,
etc. Test for blanket gas or process vapor emissions
from vent caps.
DISASSEMBLY
All service on the regulator may be performed with
the following common tools:
7/16" thru 1" box end wrenches
3/8" open end wrench*
3/16" Allen key
*Wrench must be 16" long for flanged units.
Thread a 1/2" pipe nipple into the sense port on the
lower diaphragm case [15]. Use a vise and clamp
onto the pipe nipple. This makes a good holding
fixture and provides some degree of rotation while
working on the regulator.
Remove the adjustment screw cap [1] and loosen the
jam nut [3]. Turn the adjustment screw [2]
counterclockwise to completely relax the spring [6].
Remove the cap screws [28] and the lock washers
[29]. Remove the spring bonnet [4]. Remove the
spring upper button [5], the spring [6], the lower
spring button [5] and then the bonnet adapter ring
[10]. Use a 3/8" open end wrench and insert it
through the inlet port to hold onto the piston [24] at
the wrench flats. Remove the upper piston pin [8]
while holding onto the piston. Be careful not to let
the piston rotate during removal of the upper piston
pin. The piston diaphragms [21] can easily be torn if
care is not taken.
Figure 7: Piston/Body Assembly
9
8
21
24
WRENCH
FLATS
20
Remove the upper diaphragm retainer [9] and the
upper piston diaphragm [21].
WARNING
Before removing the regulator from the tank for
service, block supply pressure and vent all trapped
pressure. Never attempt to remove the regulator
from the line if it is pressurized.
Figure 6: Spring Bonnet Assembly
1
2
3
5
4
6
28
7
29
WARNING
Do NOT attempt to remove the spring chamber [4],
flow orifice locking screw [36], or any pipe
connections from the body [20], while the regulator
is pressurized.
WARNING
Diaphragm actuator case and regulator body are
exposed to the process vapor(s). Observe all
standard safety precautions as specified on Material
Safety Data Sheets for the product(s) that are in the
tank. These precautions apply both during removal
of the regulator from the tank and while repairing
it.