Brooks Instrument MT3809G - Manual (Page 50)

4-4
Installation and Operation Manual
X-VA-MT3809G-MT3810G-eng
Part Number: 541B182AAG
September, 2013
Models MT3809G & MT3810G
Section 4 Maintenance
4. Reassemble by inserting the float assembly inside the conical taper
(as well as the spacer bushing, size 16 only). Then insert the complete
float assembly into the bottom of the meter. Replace the float assembly
inlet guide cartridge and tighten the float assembly into place.
2. NPT Connection
a. Size 7 (½") NPT, liquid or gas service
1. Remove the meter from the process line and lay the meter horizontal on
a table.
2. Unscrew the inlet fitting at the bottom of the meter.
3. Push the entire float assembly slowly downward and out of the meter
inlet by pushing from the top with a round bar stock (3/4” or 19 mm
diameter).
4. Remove the float snap-ring and clean individual float assembly parts.
5. Reassemble the meter by reassembling the float assembly and inserting
it into the bottom of the meter. Reinstall and secure the inlet fitting.
b. Size 8 (½"), 10 (1"), 12 (1½") NPT liquid service
1. Remove the meter from the process line and lay the meter horizontal on
a table.
2. Unscrew the inlet fitting at the bottom of the meter.
3. Loosen the float assembly with two screwdrivers one on each end of the
meter and turn to loosen the inlet and outlet screws. Remove inlet screw at
the bottom of the meter.
4. Remove the guide vane at the bottom of the meter and gently push the
float assembly up and out the top/outlet side.
5. Reassemble by inserting the float assembly into the top of the meter.
Replace the guide vane and secure the float assembly by tightening the
inlet and outlet screws . Reinstall and secure the inlet fitting.
c. Size 8 (½”) NPT gas service
1. Remove the meter from the process line and lay the meter horizontal on
a table.
2. Unscrew the outlet fitting at the top/outlet of the meter and remove the
gas damper.
3. Unscrew the inlet/bottom fitting and slowly remove the float assembly.
4. To reassemble the meter, insert the float assembly into the inlet/bottom
of the meter. Secure the inlet/bottom fitting. Replace the gas damper and
secure the outlet/top fitting.
d. Size 10 (1"), 12 (1½") NPT, gas service
1. Remove the meter from the process line and lay the meter horizontal on
a table.
2. Remove the top/outlet screw.
3. Loosen the float assembly by holding the damper in place with a pin (1/
8” diameter) in the top while loosening the inlet/bottom fitting.
Gently push the float assembly out through the inlet/bottom.
4. To clean the gas damper, unscrew the cylinder head. Then remove the
bolt and take out the small piston carefully so as to not damage the critical
surfaces.
5. Reassemble the meter by inserting the float assembly with damper into
the inlet/bottom of the meter. Secure the inlet/bottom screw by holding the
damper in place with a pin (1/8” diameter). Replace and secure the top/
outlet screw. Reinstall and secure the inlet fitting.