805 Liberty Boulevard
DuBois, PA 15801
1-800-375-8875
For more information, visit us at sensus.com/gas
Caution
Caution
Model 496
Domestic Service Regulator Installation and Maintenance Instructions
I
It is the user’s responsibility to assure that all regulator vents
and/or vent lines exhaust to a non-hazardous location away
from ANY POTENTIAL sources of ignition. Where vent lines
are used, it is the user’s responsibility to assure that each
regulator is individually vented and that common vent lines
ARE NOT used.
8. The vent connection is an escape path for the regulated
gas. Depending upon the type of gas, it could be
flammable as with natural gas and propane. Therefore,
the vent connection needs to be located and/or piped so
that potential discharge occurs in a safe area away from
buildings, open flames, collection areas, arcing devices, etc.
Regulators that are installed indoors or in a non-vented
area must be vented to the outside. Run vent piping from
the regulator vent connection to a non-hazardous location
on the outside away from any potential sources of ignition.
Since the Model 496 regulator is equipped with internal relief
valves (IRV), the vent piping must be vent connection size
or larger and its length be as short and direct as possible
to a safe area. This is to assure the venting of the internal
relief valve discharge to the atmosphere without excessive
pressure increase in the regulator and downstream piping.
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.
9. 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.
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
), remove body-to-
diaphragm case screws from body (
5
) with a 1/2” standard
socket (or standard screwdriver) and remove diaphragm
case assembly from body (
5
).
3. To replace 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 7/8” hex
socket wrench. Apply sealant on threads of orifice when
installing replacement orifice. The 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. Ensure proper seal and verify
no leaks by using a soap and water solution or other utility-
approved method..
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 device or similar device.
Buried Service
The Model 496 regulator is not recommended for buried
service.
Temperature Limits
The Model 496 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 regulator case may be
subjected under abnormal conditions without causing damage
to the internal parts of the regulator 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.)
All products purchased and services performed are subject to Sensus’ terms of sale, available at either; http://na.sensus.com/TC/TermsConditions.pdf or 1-800-METER-IT.
Sensus reserves the right to modify these terms and conditions in its own discretion without notice to the customer.
This document is for informational purposes only, and SENSUS MAKES NO EXPRESS WARRANTIES IN THIS DOCUMENT. FURTHERMORE, THERE ARE NO IMPLIED
WARRANTIES, INCLUDING WITHOUT LIMITATION, WARRANTIES AS TO FITNESS FOR A PARTICULAR PURPOSE AND MERCHANTABILITY. ANY USE OF THE
PRODUCTS THAT IS NOT SPECIFICALLY PERMITTED HEREIN IS PROHIBITED.
©
2012 Sensus USA Inc.
