Instruction Manual
D100703X012
July 2019
Type 92B Pressure Reducing Valve
WARNING
!
Failure to follow these instructions or
to properly install and maintain this
equipment could result in an explosion,
re and/or chemical contamination
causing property damage and personal
injury or death.
Fisher™ regulators must be installed,
operated and maintained in accordance
with federal, state and local codes, rules
and regulations and Emerson Process
Management Regulator Technologies, Inc.
(Emerson) instructions.
Type 92B
If the regulator vents gas or a leak
develops in the system, service to the unit
may be required. Failure to correct trouble
could result in a hazardous condition.
Installation, operation and maintenance
procedures performed by unqualied
personnel may result in improper
adjustment and unsafe operation. Either
condition may result in equipment
damage or personal injury. Use qualied
personnel when installing, operating and
maintaining the Type 92B regulator.
Introduction
Scope of the Manual
This manual provides instructions for installation,
startup, maintenance and parts ordering information
for the Type 92B Valve. Instructions and parts lists for
other equipment used with these valves are found in
separate manuals. The Type 92B is also available with
a Type 6492HM or 6492HTM safety override pilot.
Product Description
The Type 92B Pressure Reducing Valve is the
standard steam valve for industry. It can withstand
W8264
Figure 1. Type 92B Pressure Reducing Valve
dirty operating environments while providing accurate
and stable pressure control. The Type 92B is applied
as a main pressure reducing valve in industrial
process heating applications such as heat exchangers,
evaporators, digesters and reactors. Commercial
applications include pressure reducing valves for
meter runs found in district energy systems, hot
water heat exchangers, absorption chillers and boiler
deaerator tanks.
A Type 6492HM safety override pilot is available for
the Type 92B. The Type 92B pilot is used in a series
installation with the Type 6492HM safety override pilot
installed on the upstream valve. The Type 6492HM
safety override pilot senses pressure downstream of the
second valve and prevents pressure from rising above
safe operating pressure in the event the downstream
valve fails. This system is approved by ASME
B31.1-1989, 122.14.2.A, and can replace an ASME
safety valve when vent piping is not practical and
upstream steam pressure does not exceed 400 psig /
27.6 bar. Local codes and standards may require
approval by an appropriate authority prior to installation.
Type 92B
Specications
Specications are given for the Type 92B valve on below. Specications for a given valve as it originally comes from
the factory are stamped on the nameplate.
Available Congurations
Pilot-operated globe-style pressure
reducing valve with post guiding and ow-to-close
valve plug action
Body Sizes and End Connection Styles
See Table 1
Body Ratings and Maximum Inlet Pressures
(1)
See Table 3
Maximum Outlet (Casing) Pressure
Cast Iron: 150 psig / 10.3 bar or body rating
limit, whichever is lower
Steel/Stainless steel: 300 psig / 20.7 bar or body
rating limit, whichever is lower
Outlet Pressure Ranges
(1)
Minimum Dierential Pressure Required for
Full Stroke
20 psig / 1.4 bar with stainless steel
spring; 10 psig / 0.69 bar with Inconel® spring
Pressure Registration
External
Temperature Capabilities
See Table 3
Downstream Control Line Connections
NPS 1 and 1-1/2 / DN 25 and 40 bodies:
1/4 NPT
NPS 2 / DN 50 body: 3/8 NPT
NPS 3 and 4 / DN 80 and 100 bodies: 1/2 NPT
See Table 2
1. The pressure/temperature limits in this Instruction Manual or any applicable standard limitation should not be exceeded.
Table 1. Body Sizes and End Connection Styles
BODY SIZES END CONNECTION STYLE
NPS DN Cast Iron Body
1 25 NPT
1-1/2 and 2 40 and 50
3 and 4 80 and 100
1. Available in steel bodies only.
NPT,
CL125 FF and
CL250 RF
CL125 FF
and CL250 RF
(1)
(1)
Steel or
Stainless Steel Body
NPT, SWE
and PN 16/25/40 RF
CL150 RF, CL300 RF,
PN 16 RF and PN 25/40 RF
CL150 RF,
CL300 RF
(1)
,
PILOT TYPE
Low
Pressure
High
Pressure
High
Temperature
OUTLET PRESSURE
psig bar In. mm In. mm
2 to 6
5 to 15
13 to 25
15 to 30
25 to 75
70 to 150
15 to 100
80 to 250
0.14 to 0.41
0.34 to 1.0
0.90 to 1.7
1.0 to 2.1
1.7 to 5.2
4.8 to 10.3
1.0 to 6.9
5.5 to 17.2
WARNING
!
The Type 92B safety override system
does not provide positive shuto in
dead end service. It is intended for
large distribution systems where steam
Inconel® is a trademark owned by Special Metals Corporation.
2
Table 2. Outlet Pressure Ranges
PART NUMBER COLOR CODE
1E395627022
1D7455T0012
1E395727192
1E395627022
1D7455T0012
1E395727192
14B9943X012
14B9942X022
Yellow
Green
Red
Yellow
Green
Red
Unpainted
Unpainted
leakage will condense before steam
pressure builds up. Downstream piping
and components must be rated for
maximum upstream steam pressure for
dead end service. Failure to do so could
cause personal injury or death.
SPRING WIRE DIAMETER SPRING FREE LENGTH
0.207
0.234
0.283
0.207
0.234
0.283
0.282
0.375
5.26
5.94
7.19
5.26
5.94
7.19
7.16
9.53
2.50
2.62
2.44
2.50
2.62
2.44
2.50
2.50
63.5
66.5
62.0
63.5
66.5
62.0
63.5
63.5
Type 92B
CONTROL LINE
MAIN VALVE
DIAPHRAGM
VALVE PLUG
E0672_1
INLET PRESSURE
OUTLET PRESSURE
ATMOSPHERIC PRESSURE
LOADING PRESSURE
ORIFICE
MAIN VALVE SPRING
PILOT CONTROL LINE
Figure 2. Type 92B Operational Schematic
PILOT SPRING
PILOT SUPPLY LINE
PILOT
DIAPHRAGM
PILOT VALVE
PLUG
Principle of Operation
Refer to the operational schematic in Figure 2.
Compression of the pilot spring pushes the diaphragm
down and holds the pilot valve plug open. Outlet
pressure is changed by varying the amount of pilot
spring compression.
When steam enters the inlet of the valve, it also enters
the pilot supply line and ows through the open pilot
valve to the top of the main diaphragm. The force
created by this steam pressure on the diaphragm
overcomes the force of the main valve spring opening
the valve plug and allowing steam to ow downstream.
Downstream pressure registers under the main
diaphragm through the control line and tends to
balance the diaphragm. Steam from the downstream
system also registers under the pilot diaphragm
through line. Pressure forces the diaphragm upward,
permitting the pilot valve plug to move toward the
closed position. Flow of steam to the top of the main
diaphragm is thereby reduced and the pressure on
main diaphragm drops due to the bleed through the
orice. The main valve moves toward the closed
position, allowing only enough steam ow to satisfy
downstream requirements.
When steam demand increases, the downstream
pressure decreases below the setting of the pilot
spring. The pilot opens to increase the pressure on the
main diaphragm. The main valve opens to increase
the ow downstream. Conversely, if the steam demand
decreases, the downstream pressure increases and
the pilot reacts to decrease the pressure on top of
the main diaphragm. The main valve throttles toward
the closed position and the steam ow decreases.
Thus, through the combination of pilot and main valve
operation, control of the downstream steam pressure
is maintained.
A check valve is included in all Type 92B pilots to limit
dierential pressure on the main valve diaphragm.
In the event of a large decrease in downstream
pressure, the check valve opens to relieve diaphragm
loading pressure to the downstream system. The
check valve cartridge assembly has a factory setting
to limit dierential pressure across the diaphragm
to approximately 40 psid / 2.8 bar d. If diaphragm
dierential pressure exceeds 40 psid / 2.8 bar d,
the check valve opens to relieve diaphragm loading
pressure into the downstream system, thereby
preventing a high dierential across the diaphragm
which might otherwise cause diaphragm damage. The
check valve closes and normal operation resumes
when the dierential pressure across the diaphragm is
reduced to the proper level.
3
Type 92B
Table 3. Maximum Inlet Pressures and Temperatures
BODY MATERIAL END CONNECTION
NPT 250 17.2 406 208
Cast Iron
Steel
Stainless steel
1. 450°F / 232°C with standard seat ring, 600°F / 316°C with seal weld option.
PN 16/25/40 (NPS 1, 1-1/2, 2 and 3 /
PN 16/25/40 (NPS 1, 1-1/2, 2 and 3 /
(NPS 3 and 4 / DN 80 and 100)
(NPS 3 and 4 / DN 80 and 100)
CL125 FF 125 8.6 353 178
CL250 RF 250 17.2 406 208
NPT 300 20.7 450 232
SWE 300 20.7 450 232
CL150 RF 185 12.8 450 232
CL300 RF 300 20.7 600 316
DN 25, 40, 50 and 80)
PN 16 (NPS 4 / DN 100) 185 12.8 450 232
PN 25/40 (NPS 4 / DN 100) 300 20.7 600 316
NPT 300 20.7 450 232
CL150 RF 175 12.1 450 232
CL300 RF 300 20.7 600 316
DN 25, 40, 50 and 80)
PN 16
PN 25/40
MAXIMUM INLET PRESSURE MAXIMUM TEMPERATURE
psig bar °F °C
(1)
300 20.7 600 316
300 20.7 600 316
175 12.1 450 232
300 20.7 600 316
(1)
(1)
(1)
(1)
(1)
Type 6492HM Safety Override System
Refer to Figure 3. Once placed in operation, the
upstream Type 92B (B) pilot senses the intermediate
pressure between both valves, and the Type 6492HM
(A) pilot senses downstream pressure of the second
valve. As demand for ow increases, intermediate
pressure will fall causing the Type 92B pilot to open. As
the Type 92B pilot opens, loading pressure to the main
valve increases, opening the main valve.
The Type 6492HM (A) safety override pilot remains
open because its setpoint is above the setpoint of
the downstream valve. In the unlikely event that the
downstream valve fails open, downstream pressure
will rise above the downstream valve’s setpoint. This
pressure is sensed by the Type 6492HM (A) safety
override pilot. As downstream pressure increases
the Type 6492HM (A) safety override pilot closes,
reducing loading pressure to the upstream main valve,
which positions the main valve to maintain desired
downstream override pressure.
In the event that the upstream valve fails, the
downstream valve will prevent downstream pressure
from rising above safe operating levels.
It is recommended to install some type of warning
system, such as a sentinal relief valve, to warn the
operator that a valve has failed in the system. This
will prevent prolonged operation with one valve, which
could cause valve trim wear and noise associated with
operation at high dierential pressures.
Installation
WARNING
!
Regulators should be installed, operated
and maintained in accordance with
federal, state and local codes, rules and
regulations and Emerson instructions.
If the regulator vents steam or a leak
develops in the system, it indicates that
service is required.
Failure to take the regulator out of
service immediately may create a
hazardous condition.
Call a service man in case of trouble.
Only a qualied person must install or
service the regulator.
CAUTION
Be sure to install Type 92B pilot above
the pipeline with the adjusting screw
pointing up and the control line sloped
at a downward pitch to the main line to
ensure proper condensate drainage.
The following points should be kept in mind when
installing this pressure reducing valve. See Figure 4
for a schematic drawing of a typical installation.
4
TYPE 92B PILOT (B) TYPE 92B PILOT (C)
TYPE 6492HM SAFETY
OVERRIDE PILOT (A)
E0794
Type 92B
TYPE 92B MAIN VALVE TYPE 92B MAIN VALVE
INLET PRESSURE
OUTLET PRESSURE
ATMOSPHERIC PRESSURE
LOADING PRESSURE
INTERMEDIATE PRESSURE
Figure 3. Safety Override System Schematic
Table 4. Minimum Dierential Pressures for Safety Override System
TYPE
6492HM
6492HTM
SPRING RANGE
psig bar
10 to 30 0.69 to 2.1 Yellow 10 / 0.69 over normal downstream pressure
25 to 75 1.7 to 5.17 Green 10 / 0.69 over normal downstream pressure
70 to 150 4.8 to 10.3 Red 15 / 1.0 over normal downstream pressure
15 to 100 1.0 to 6.9 Unpainted 10 / 0.69 over normal downstream pressure
80 to 250 5.5 to 17.2 Unpainted 25 / 1.7 over normal downstream pressure
1. Inspect the Type 92B for any shipment damage.
Remove any foreign materials that may have collected
in the valve during shipment.
2. Blow down the pipeline as required.
3. Install a strainer ahead of the Type 92B to protect the
internal parts of the valve.
4. Install an upstream block valve ahead of the Type 92B
and a downstream block valve, if required, so that
the valve can be isolated and serviced. If continuous
operation is necessary during maintenance or
inspection, install bypass piping and valve around the
Type 92B.
SPRING COLOR
MINIMUM PRESSURE AT WHICH MONITORING
PILOT CAN BE SET, psig / bar
5. This Type 92B is intended to be installed with
the diaphragm case above the pipeline so that
condensate will not collect in the case.
6. Install the Type 92B in the pipeline so that the ow
will be in the direction indicated by the arrow cast
on the body. Follow normal piping procedures when
installing the screwed or anged control valve.
7. Install the external control line as follows:
a. Connect one end of the control line to the
Type 92B body tapping. This tapping is
1/4 NPT for NPS 1 and 2 / DN 25 and 40
bodies, 3/8 NPT for NPS 2 / DN 50 body and
1/2 NPT for NPS 3 and 4 / DN 80 and
100 bodies.
5
Type 92B
BLOCK VALVE
E0706
INITIAL
PRESSURE
GAUGE
INITIAL
PRESSURE
GAUGE
BLOCK VALVE
TRAP
BLOCK VALVE
BLOCK
VALV E
BLOCK
VALV E
STRAINER
TYPE 92B
TYPE 92B SINGLE-STAGE INSTALLATION
SENSING LINE
STRAINER
TYPE 92B
SENSING LINE
REDUCED
PRESSURE
SENSING LINE
GAUGE
REDUCED
PRESSURE
GAUGE
BLOCK
VALV E
REDUCED
PRESSURE
GAUGE
BLOCK VALVE
E0707
INITIAL
PRESSURE
GAUGE
E0708
BLOCK VALVE
BLOCK
VALV E
TRAP
STRAINER
TRAP
STRAINER
TYPE 92B
TYPE 92B SINGLE-STAGE PARALLEL INSTALLATION
BLOCK VALVE
INTERMEDIATE
PRESSURE
GAUGE
TRAP
PRIMARY
TYPE 92B
SENSING
LINE
BLOCK
VALV E
TYPE 92B TWO-STAGE INSTALLATION
Figure 4. Type 92B Typical Installations
BLOCK
VALV E
SECONDARY
TYPE 92B
TRAP
SENSING
LINE
BLOCK
VALV E
REDUCED
PRESSURE
GAUGE
6
Type 92B
TYPE 6492HM SAFETY
OVERRIDE PILOT
TYPE 92B
MAIN VALVE
TYPE 6492HM SAFETY
OVERRIDE PILOT
TYPE 92B MAIN VALVE
TYPE 92B PILOT
TYPE 92B PILOT
Figure 5. Safety Override System Installation
TYPE 92B MAIN VALVE
TYPE 92B PILOT
TOP VIEW
TYPE 92B MAIN VALVE
TYPE 92B PILOT
SIDE VIEW
Note
The control line should be as large as
the tapped hole in the Type 92B.
b. The other end of the control line is connected to
the downstream system. Place the tapped hole
for this connection in a straight run of pipe 3 to
5 ft / 0.91 to 1.52 m from the control valve when
the valve body is the same size as the pipeline.
If the valve body is smaller than the pipeline and
requires swage nipples, place the tapped hole at
a distance from the swage connection equal to 10
times the pipe diameter.
c. Do not locate the control line tap in an elbow,
swage or other changes in conguration of the
pipeline where turbulence or abnormal velocities
may occur.
d. Do not locate the control line tap in a vessel (such
as a deaerator) located immediately downstream
of the control valve. Locate the tap in the pipeline
leading to the vessel.
e. Slope the control line away from the Type 92B so
that condensate can drain back into the pipeline.
f. Install a shuto valve (not a needle valve) in the
control line.
g. Install a pressure gauge in the control line or near
the outlet of the Type 92B to aid in setting the
outlet pressure.
CAUTION
The maximum inlet and outlet pressures
for which this Type 92B has been
manufactured should not be exceeded.
These pressures are stamped on the
nameplates attached to the main valve
and pilot.
Startup and Adjustment
WARNING
!
Failure to remove accumulated
condensate may result in severe
condensation induced water hammer
which can result in personal injury
or death.
7
Type 92B
Prior to valve startup:
New Installations
Blow down inlet steam piping to remove any debris
such as weld beads by opening the drain valve of the
inlet strainer to the control valve. Close the isolation
valve and disassemble strainer to remove accumulate
debris. Repeat as necessary until strainer basket is
free of debris.
Old Installations
Open all upstream and downstream drain valves at
drip legs and strainers to drain condensate that may
have accumulated during the shutdown period. Crack
the inlet isolation valve to the pressure reducing
stations to ush any residual condensate. Close the
drain valves once the drain is free of condensate.
Pilot Adjustment
Loosen hex nut on screw before adjustment. To adjust
the downstream reduced pressure setting, turn the set
screw clockwise into the spring case to increase the
downstream pressure setting. Turn it counterclockwise
out of the spring case to decrease the setting. Tighten
it once adjustment is made.
1. Remove all pilot control spring compression
from the Type 6492HM safety override pilot
by turning the adjusting screw out of the spring
case (counterclockwise).
2. Adjust the Type 92B upstream working pilot’s and
Type 92B downstream working pilot’s adjusting
screws into the spring case (clockwise) to their
maximum adjustment.
3. Slowly open the upstream block valve to introduce
inlet pressure to the system.
4. Open the downstream block valve and control line
block valves, if used.
Note
Some ow is needed to make pressure
settings accurate.
5. If a bypass is used, slowly close the bypass line
block valve.
6. Adjust the Type 6492HM safety override pilot to
the desired downstream override pressure. The
safety override pilot’s setpoint must be higher than
the downstream working pilot’s setpoint by the
amounts listed in Table 4.
Type 92B
To put the valve into operation after installation or
after disassembly for inspection or repairs, proceed as
follows, referring to Figures 4, 9 and 10 as necessary.
1. Relieve all spring compression on the pilot spring
by loosening hex nut (key 16) and turning set
screw (key 15) counterclockwise (out of the
spring case).
2. Open the upstream block valve.
3. Open the downstream block valve slowly.
4. Close the bypass valve.
5. Slowly turn the set screw of the pilot clockwise
into the spring case until the downstream pressure
reaches the required setting. Tighten hex nut on
the set screw.
Safety Override System
Use the following procedure to put the system into
operation, referring to Figure 3 as necessary:
Note
The normal pressure and maximum
override pressure should be set at
or below the safe working pressure
of the equipment and piping system
downstream. (Reference applicable
codes and/or standards for maximum
allowable or safe working pressures for
equipment and piping systems served.)
7. Adjust the Type 92B downstream working pilot to the
desired normal downstream control pressure.
8. Adjust the Type 92B upstream working pilot to the
desired intermediate control pressure (typically 50% of
inlet pressure).
9. Readjust the Type 92B downstream working pilot to
the desired normal downstream control pressure,
if necessary.
10. Tighten the lock nuts on all pilots to lock the
adjusting screws in position.
8
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