1
2
11
8
9
5
7
6
12
10
4
3
The outlet of the vent piping must allow for free and
unobstructed passage of air and gas and must be protected
against the potentials listed in instructions #4, #8 and #9.
10.
For outdoor installations, it is recommended that the regulator
be installed so that the regulator vent faces downward to avoid
the potential for water and other foreign matter entering the
regulator and interfering with the proper operation of the
regulator.
CAUTION:
Regulators are pressure control devices with numerous moving
parts subject to wear that is independent upon particular operating
conditions. To assure continuous satisfactory operation, a periodic
inspection schedule must be adhered with the frequency of
inspection determined by the severity of service and applicable
laws and regulations.
Servicing
1.
To access valve
7
, orifice
6
, or diaphragm assembly
8
,
first remove spring compression by unscrewing the
spring cap
1
and spring adjustment ferrule
2
.
Remove spring
3
from regulator.
2.
For access to the valve
7
and orifice
6
, completely loosen
the coupling nut
12
and remove diaphragm case assembly
from body
5
.
3.
To replace Buna-Nitrile valve pad
7
, simply pull off of valve
stem
9
and replace with new pad.
4.
To replace orifice
6
, unscrew from body using a 1" hex
socket wrench “thin-wall” type. Apply sealant on threads of
orifice when installing replacement orifice. Re-screwing
replacement orifice must be installed at 50-60 ft-lbs. of torque.
5.
To replace diaphragm assembly, remove flange screws
10
and disassemble diaphragm assembly. Make certain all parts
are reassembled in their correct order and all threads and
joints are tightened evenly and firmly.
6.
Before reassembling body to diaphragm case, make certain
that the o-ring is in position.
Over Pressurization Protection
Protection must be provided for the downstream piping system
and the regulator's low pressure chambers to assure against
the potential for over pressurization due to a regulator malfunction
or a failure of the regulator to lock up. The allowable over-
pressurization is the lowest of the maximum pressures permitted
by federal codes, state codes, Sensus Bulletin RDS-1498,
or other applicable standards. The methods of providing over-
pressure protection could be a relief valve, a monitor regulator,
a shut-off valve or similar device.
Buried Service
The Model 143-80 regulator is not recommended for buried
service.
Temperature Limits
The Model 143-80 regulator can be used for the flowing
temperature of -20°F to 150°F (-28.9°C to 65.5°C).
Maximum Emergency Pressures
The maximum pressure the regulator inlet may be subjected under
abnormal conditions without causing damage to the regulator is:
Maximum Inlet Pressure plus 50 psi.
The maximum pressure to which the regulators case may be
subjected under abnormal conditions without causing damage
to the internal parts is: Set point plus 3 psi. If the outlet pressure
exceeds this pressure, the regulator must be removed from service
and carefully inspected. Damaged or otherwise unsatisfactory
parts must be replaced before returning the regulator to service.
The maximum outlet pressure that can be safely contained in
the diaphragm case is 10 psi (safely contained means no leakage
as well as no bursting.)
01-08-Becken 100M
805 Liberty Boulevard
DuBois, PA 15801
800-375-8875
Fax: (814) 375-8460
www.sensus.com
© Sensus Metering Systems 2008
Made in USA
Model 143-80-1
