Instruction Manual
VENT
V
E
N
T
VENT
VENT
VENT
Form MCK-1106
June 1986
Low Pressure Regulators
Single and Second-Stage LP-Gas Regulators
C
VENT CAN BE PLACED IN
POSITION C, D, E, OR F
CLOSING
CAP
D
OUTLET
INLET
WARNING
!
Fisher equipment must be installed, operated,
and maintained in accordance with federal,
state, and local codes and Fisher instructions.
The installation in most states must also
comply with NFPA No. 54 and 58 standards.
Only personnel trained in the proper
procedures, codes, standards, and
regulations of the LP-gas industry should
install and service this equipment. Failure
to follow these instructions or to properly
install and maintain this equipment could
result in an explosion and/or fire causing
property damage and personal injury
or death.
Things To Tell The Gas Customer:
1. Point out the regulator’s vent to the customer
(or vent assembly or vent tube), and stress that this
opening must remain unobstructed at all times. Tell
the customer to be sure to check the vent opening after a
freezing rain, sleet storm, or snow to make sure ice has not
formed in the vent.
OUTLET
CLOSING
CAP
F
VENT CAN BE
OVER INLET
OR OUTLET
INLET
Figure 1. Typical Regulator Configurations
E
Description
All the regulators are designed for low pressure
(inches of water column) vapor service and are not to be
used for liquid service. Their ou
usually 11-inches w.c (27 mbar).
Single-stage regulators (reducing container pressure
to 11-inches w.c. (27 mbar)) are normally painted gray
while second-stage regulators (reducing the outlet
of a first-stage regulator to 11-inches w.c. (27 mbar))
are normally painted palm green. The units differ in
construction and capacity rating.
tlet pressure setting is
2. Show the customer the shutoff valve on the container.
The customer should close this valve immediately if gas can
be smelled, appliance pilot lights fail to stay on or appear
higher than usual, or any other abnormal situation occurs.
3. Tell the customer to call your company to service the
regulator. If the regulator vents gas or leak develops in
the system, only qualifie
d gas serviceman should install or
service the regulator.
Introduction
Scope of Manual
This instruction manual covers installation and maintenance
for the following single and second-stage LP-gas regulators:
Types 912, R322 (integral two-stage), R352, R722, R922,
R932, and S102L.
R
Specifications
The Specifications table lists the specifications for the
regulators. Contact the factory if the regulators are to be
used on any service other than LP-gas, natural gas, or
air. Temperature li
Second-stage regulators are limited to 20 psig (1,4 bar) inlet
pressure and must be used with a first-stage regulator.
Installation
All vents should be kept open to permit
free flow of air into and out of the regulator.
Protect openings against the entrance of
rain, snow, ice formation, paint, mud, insects,
or any other foreign material that could plug
the vent of vent line.
www.FISHERregulators.com/lp
mits are -20° to 160° F (-29° to 71° C).
WARNING
!
D450023T012
Low Pressure Regulators
VENT
Specifications
TYPE NUMBER
†
912
R322 1/4 1/2 or 3/4 Integral Two-Stage 250 (17,2) 660,000
R352 3/4 3/4 Second-Stage 20 (1,38) 1,250,000
R722
R922
R932
S102L 3/4 – 1-1/2 3/4 – 1-1/2 Second-Stage 20 (1,38) 2,000,000
*320,000 BTU/Hr. with pigtails
INLET CONNECTION OUTLET CONNECTION
3/4 or F. POL
1/4, 1/2 or F. POL 1/2 or 3/4 Single-Stage 250 (17,2) 725,000
3/4 or F. POL
SIZE, INCH FNPT
1/4 1/4 or 3/8 Single-Stage 250 (17,2) 350,000*
3/4 Single-Stage 250 (17,2) 4,250,000
3/4 3/4 Second-Stage 20 (1,38) 2,500,000
1/2 1/2 or 3/4 Second-Stage 20 (1,38) 750,000
3/4 Single-Stage 250 (17,2) 1,200,000
1/2 3/4 Second-Stage 20 (1,38) 1,250,000
#
437,500 BTU/Hr. with pigtails
POINT VENT
DOWN
†
Vent not normally tapped for vent tubing
TYPE OF SERVICE
TO APPLIANCES
VENT
LINE
BASEMENT
MAXIMUM INLET
PRESSURE,
PSIG (bar)
VAPOR CAPACITY,
BTU/HR.
PROPANE
#
VENT
ASSEMBLY
VENT OPENING
MUST BE AT LEAST
3-FEET (0,91 meters)
HORIZONTALLY
FROM ANY BUILDING
OPENING BELOW IT
Figure 2. Point Vent Down on Outdoor Installations
LP-gas may discharge to the atmosphere
through the vent. An obstructed vent which
limits air or gas flow can cause abnormally
high pressure that could result in personal
injury or property damage. Failure to use a
vent line on indoor installations can cause a
hazardous accumulation of gas which could
result in personal injury or property damage.
Never use a first-stage (pounds to pounds)
regulator on low pressure (inches of water
column) service because personal injury or
property damage could occur.
Make sure gas flow through the regulator is in the same
direction as the arrow on the body – ”Inlet” and “Outlet”
connections are clearly marked. The installation should be
adequately protected from vehicular traffic and damage from
other external sources. Install the regulator so that any gas
discharge through the vent or vent assembly is over 3-feet
(0,91 meters) horizontally from any building opening below
the level of the discharge.
Install the regulator high enough above ground level – at least
18-inches (457 mm) – so that rain splatter cannot freeze in the
FROM FIRST STAGE
REGULATOR
Figure 3. Typical Indoor Installation With
Vent Line and Vent Assembly
vent. Whether a protective hood is used or not, do not install
the regulator in a location where there can be excessive water
accumulation or ice formation, such as directly beneath a
down spout, gutter, or roof line of a building.
A regulator installed outdoors without a protective hood
must have its vent pointed vertically down, see figure 2, to
allow condensate to drain. This minimizes the possibility of
freezing and of water or other foreign material entering the
vent and interfering with proper operation.
Before installing the regulator, check for damage which might
have occurred in shipment. Also check for and remove any
dirt or foreign matter which may have accumulated in the
regulator body or the pipeline. Apply pipe compound to the
male threads of the pipe.
Some installations, such as in areas with heavy snow fall
or on recreational vehicles where there is road splatter,
2
Low Pressure Regulators
GRADE AROUND DOWNWARD AND
AWAY AROUND HOUSING DOME. THIS
PREVENTS WATER COLLECTING AND
RUNNING INTO OR STANDING AROUND
HOUSING DOME.
REGULATOR ADJUSTMENT CLOSURE CAP
MUST BE TIGHT.
WATER MARK LEFT IN HOUSING DOME AT LEVEL ABOVE REGULATOR
VENT OR END OF VENT TUBE REQUIRES REPLACEMENT OF
REGULATOR. THEN CORRECT INSTALLATION.
Figure 4. Regulators Installed on Underground Installations Require a Vent Tube
may require a hood or enclosure to protect the regulator.
Horizontally mounted regulators, such as found on single
cylinder installations, must be installed beneath a protective
cover. If possible slope or turn the vent down sufficiently to
allow any condensation to drain out of the spring case. Be
careful that the slot in the hood or cover for the regulator’s
outlet piping does not extend too far and expose the vent to
the elements.
Regulators installed indoors are limited to 20 psig (1,38 bar)
maximum inlet pressure, and they require a vent line to the
outside of the building, see figure 3. A vent assembly, such
as Fisher Y602 series, should be used on the end of the
vent line. The same installation precautions apply to vent
assemblies as the integral regulator vents covered previously.
Use pipe or tubing equal in size to the regulator’s vent for the
vent line. To install the vent line, remove the vent screen and
apply a good grade of pipe dope to the male threads of the
line. Vent piping or tubing must not restrict the flow passage
of the regulator’s internal relief valve.
Underground container systems require a vent tube to
prevent water from entering the regulator spring case, see
figure 4. Remove the vent screen and install the vent tube,
such as a Fisher Type P203. The vent tube must be run
from the regulator vent to above the maximum water table.
The vent tube opening must terminate at the extreme top
inside of the dome cover. Make sure the regulator’s closing
cap is on tightly, and maintain drainage away from the
dome at all times. For further information on underground
installations, write for a copy of “Underground LP-Gas
Systems: Suggested Installation, Inspection,” available from
the National LP-Gas Association, 1301 W. 22nd St., Oak
Brook, IL 60521.
Adjustment
Each regulator is individually factory set to deliver
11-inches w.c (27 mbar). If it becomes necessary to
increase the outlet pressure, remove the closing cap, figure
1, and turn the adjusting screw clockwise. Turn the adjusting
screw counterclockwise to decrease the outlet pressure. A
pressure gauge or water manometer is needed to determine
the regulator’s outlet setting after adjustment. Always
replace the closing cap after adjustment.
END OF REGULATOR VENT TUBE
LOCATED AT TOP INSIDE OF HOUSING
DOME COVER.
2-INCHES (51 mm)
MINIMUM
Overpressure Protection
WARNING
!
Personal injury or system damage may result
if these regulators are installed without
appropriate overpressure protection. Outlet
pressures greater than 3 psig (0,20 bar) above
the set point may cause damage to regulator
parts, leaks in the regulator, or personal injury
due to bursting of pressure-containing parts
or explosion of accumulated gas.
If the regulator is exposed to an overpressure
condition, it must be inspected for any
damage that may have occurred.
Large volumes of gas may discharge through
the regulator vent during internal relief
valve operation which can result in fire or
explosion from accumulated gas.
All of the regulators have an internal relief valve that opens
when downstream pressure reaches approximately 1 psig
(0,069 bar) on regulators set at 11-inches w.c. (27 mbar).
When the internal relief valve opens, gas escapes to the
atmosphere through the regulator’s vent. The Internal
relief valve gives overpressure protection against excessive
build-up resulting from seat leakage due to worn parts or
chips of foreign material on the orifice.
Some type of external overpressure protection must be
provided if inlet pressure will be high enough to damage
downstream equipment. Common methods of external
overpressure protection include relief valves, see
figure 5, monitoring regulators, shutoff devices, and series
regulation. The internal relief valve on second-stage and
integral two-stage regulators with the 3/4-inch (19 mm) vent
(Types R322, R352, and R922) limits downstream pressure
to 2 psig (0,14 bar) as long as inlet pressure does not
exceed 20 psig (1,38 bar) and the vent is unobstructed.
3
Low Pressure Regulators
PLACE PROTECTIVE CAP
ON VENT PIPE
TYPE 289
SERIES
TYPE R722
SERIES
Figure 5. External Relief Valve Protects Downstream System
POINT VENT
DOWN
Maintenance
WARNING
!
To avoid personal injury or equipment
damage, do not attempt any maintenance
or disassembly without first isolating the
regulator from system pressure and relieving
all internal pressure.
Regulators that have been disassembled for
repair must be tested for proper operation
before being returned to service. Only parts
manufactured by Fisher should be used for
repairing Fisher regulators. Relight pilot lights
according to normal startup procedures.
Due to normal wear or damage that may occur
from external sources, these regulators must
be inspected and maintained periodically.
The frequency of inspection and replacement
of the regulators depends upon the severity
of service conditions or the requirements of
local, state, and federal regulations. Even
under ideal conditions, these regulators
should be replaced after 15 years from
the date of manufacture or sooner should
inspection reveal the need.
Visually inspect the regulator each time a gas delivery is
made for:
1. Improper installation.
2. Plugged or frozen vent.
3. Wrong regulator or no regulator in the system.
4. Internal or external corrosion.
5. Age of the regulator.
6. Any other condition that could cause the uncontrolled
escape of gas.
Failure to do the above could result in personal injury or
property damage.
Make sure the regulator vent, vent assembly, or vent tube
does not become plugged by mud, insects, ice, snow,
paint, etc. The vent screen aids in keeping the vent from
becoming plugged, and the screen should be clean and
properly installed.
Replace any regulators that have had water in their spring
case or show evidence of external or internal corrosion.
Checking for internal corrosion may require complete
removal of the adjusting screw and shut down of the gas
system. Closely examine regulators directly connected
to the container valve by means of a solid POL adaptor
(horizontal mounting) for signs of corrosion. Correct any
improper installations.
Older regulators are more likely to catastrophically fail
because of worn or corroded parts. Replace regulators
over 15 years of age; other service or environmental
conditions may dictate replacement of the regulator before
it becomes 15 years old, refer to Fisher Bulletin LP-32.
Regulator Repair
Regulators that have been disassembled for repair must
be tested for proper operation before being returned to
service. Fisher Type Y499-2 test rack can be furnished for
this purpose. Only parts manufactured by Fisher should be
used for the repair of Fisher regulators. Be sure to give the
complete type number of the regulator when corresponding
with the factory.
Fisher and Fisher Regulators are marks owned by Fisher Controls International, LLC. The Emerson logo is a trademark and service mark of Emerson Electric Co. All other marks are the
property of their respective owners.
The contents of this publication are presented for informational purposes only, and while every effort has been made to ensure their accuracy, they are not to be construed as warranties or guarantees, express
or implied, regarding the products or services described herein or their use or applicability. We reserve the right to modify or improve the designs or specifications of such products at any time
without notice.
Fisher does not assume responsibility for the selection, use or maintenance of any product. Responsibility for proper selection, use and maintenance of any Fisher product remains solely with
the purchaser.
Emerson Process Management
Fisher Controls International, LLC.
P.O. Box 8004
McKinney, Texas 75070, USA
Telephone: 1 (800) 588-5853
Telephone: 1 (469) 293-4201
©Fis her Cont rols Inte rna tio nal, LLC., 1986; All R ights Reserved
www.FISHERregulators.com/lp
ed
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