EMERSON 6350 Series Pilots for Pilot Operated Pressure Reducing Regulators Instruction Manual
- June 17, 2024
- Emerson
Table of Contents
EMERSON 6350 Series Pilots for Pilot Operated Pressure Reducing
Regulators
Product Information
Specifications
- Maximum Pilot Supply Pressure: 600 psig / 41.4 bar
- Outlet Pressure Ranges: See Table 1
- Pilot Restriction Code: S – Standard gain, L – Low Gain, H – High gain
- Connections: 1/4 NPT internal
- Approximate Weight: 2 pounds / 1 kg
Product Description
The 6350 Series pilots have been designed to ensure maximum pressure control
accuracy and fast response in a wide variety of applications. They are
suitable for use in natural gas distribution systems, fuel gas supply to
industrial boilers, furnaces, ovens, and mixers, as well as large
commercial/industrial establishments such as shopping centers and schools.
They can also be used in plant air and in liquid service.
Principle of Operation
Pilot-operated regulators use inlet pressure as the operating medium, which is
reduced through pilot operation to load the actuator diaphragm. Outlet or
downstream pressure opposes loading pressure in the actuator and also opposes
the pilot control spring.
Product Usage Instructions
Installation
- Ensure that the pressure/temperature limits specified in the instruction manual or any applicable standard are not exceeded.
- For stability or overpressure protection, a reducing regulator may be installed upstream of the pilot according to the Installation section.
- Connections threaded to various national or international standards can usually be supplied. Contact your local Sales Office for more information.
Startup
Follow the steps below to start up the 6350 Series pilot:
- Ensure that the pilot is properly installed according to the Installation section.
- Verify that the pilot control spring range is displayed on the pilot spring case.
- Check the pilot restriction code stamped on the pilot body (S=standard gain, L=low gain, H=high gain).
- Connect the pilot to the appropriate outlet pressure range according to Table 1.
Maintenance
To ensure optimal performance and longevity of the 6350 Series pilot, regular
maintenance is recommended. Follow these guidelines:
- Inspect the pilot for any signs of damage or wear.
- Clean the pilot and remove any debris or contaminants.
- Check and adjust the pilot control spring if necessary.
- Replace any worn or damaged parts with genuine replacement parts.
Parts Ordering
If you need to order parts for your 6350 Series pilot, refer to the parts list
in the full product literature or contact your local Sales Office for
assistance.
FAQ
Q: What is the maximum pilot supply pressure for the 6350 Series pilots?
A: The maximum pilot supply pressure for the 6350 Series pilots is 600 psig /
41.4 bar.
Q: What are the outlet pressure ranges for the different models of 6350
Series pilots?
A: The outlet pressure ranges are as follows:
- 6351: 3 to 20 psig / 0.21 to 1.4 bar / 14 in. w.c. to 2 psig
- 6352: 5 to 35 psig / 0.35 to 2.4 bar / 2 to 10 psig
- 6353: 35 to 100 psig / 2.41 to 6.9 bar / 35 to 125 psig
- 6354L: 0.21 to 2.8 bar / 85 to 200 psig
- 6354M: 2.4 to 8.6 bar / 175 to 220 psig
- 6354H: 13.8 to 20.7 bar / 200 to 300 psig
Q: What are the different spring colours and part numbers for the 6350
Series pilots?
A: The spring colours and part numbers are as follows:
- Green – Spring Part Number: 1B986027212
- Silver – Spring Part Number: 1B788327022
- Red – Spring Part Number: 1K748527202
- Yellow – Spring Part Number: 14A9672X012 (Without diaphragm limiter)
- Black – Spring Part Number: 14A9673X012 (With diaphragm limiter)
- Blue – Spring Part Number: 1E392527022 (Without diaphragm limiter)
- Green – Spring Part Number: 1K748527202 (With diaphragm limiter)
- Blue – Spring Part Number: 1L346127142
Introduction
Scope of the Manual
This manual provides installation, startup, maintenance, and parts ordering
information for the 6350 Series pilots used together with Pilot- Operated
Pressure Reducing Regulators in low-pressure applications. For information on
mounting on Pilot-operated Regulators, refer to the full product literature:
Type 1098-EGR: D100339X012
Type EZL: D103091X012
Product Description
The 6350 Series pilots have been designed to ensure maximum pressure control
accuracy and fast response in a wide variety of applications: natural gas
distribution systems; fuel gas supply to industrial boilers, furnaces, ovens,
and mixers; and large commercial/industrial establishments such as shopping
centres and schools. They can also be used in plant air and in liquid service.
Specifications
The Specifications section lists pressure limitations and other specifications
for various models of 6350 Series pilots. Please note that the pilot control
spring range is displayed on the pilot spring case, and the pilot restriction
code is stamped on the pilot body (S=standard gain, L=low gain, H=high gain).
- Maximum Pilot Supply Pressure(1)(2) 600 psig / 41.4 bar
- Outlet Pressure Ranges See Table 1
- Process Temperature Capabilities(1)
- Standard Elastomers: -20 to 150°F / -29 to 66°C
- High-Temperature Elastomers: 0 to 300°F / -18 to 149°C, except 0 to 180°F / -18 to 82°C for water service
- Pilot Restriction Code
- S – Standard gain
- L – Low Gain
- H – High gain
- Connections(3) 1/4 NPT internal
- Approximate Weight 2 pounds / 1 kg
- The pressure/temperature limits in this instruction manual or any applicable standard limitation should not be exceeded.
- For stability or overpressure protection, a reducing regulator may be installed upstream of the pilot according to the Installation section.
- Connections threaded to various national or international standards can usually be supplied. Contact your local Sales Office.
Table 1 . Outlet Pressure Ranges
PILOT TYPE| OUTLET (CONTROL) PRESSURE RANGE| SPRING COLOR|
SPRING PART NUMBER
---|---|---|---
| 3 to 20 psig| 0.21 to 1.4 bar| Green| 1B986027212
6351| 5 to 35 psig| 0.35 to 2.4 bar| Silver| 1B788327022
| 35 to 100 psig| 2.41 to 6.9 bar| Red| 1K748527202
6352| 14 in. w.c. to 2 psig| 35 mbar to 0.14 bar| Yellow| 14A9672X012
2 to 10 psig| 0.14 to 0.69 bar| Black| 14A9673X012
6353| 3 to 40 psig| 0.21 to 2.8 bar| Yellow| 1E392527022
35 to 125 psig| 2.4 to 8.6 bar| Red| 1K748527202
6354L(1)| 85 to 200 psig(1)| 5.9 to 13.8 bar(1)| Blue| 1L346127142
6354M(2)| 175 to 220 psig(2)| 12.1 to 15.2 bar(2)| Blue| 1L346127142
6354H| 200 to 300 psig(2)| 13.8 to 20.7 bar(2)| Green| 15A9258X012
1. Without diaphragm limiter.
2. With diaphragm limiter.
OVERVIEW
Principle of Operation
Pilot-operated regulators use inlet pressure as the operating medium, which is reduced through pilot operation to load the actuator diaphragm. Outlet or downstream pressure opposes loading pressure in the actuator and also opposes the pilot control spring. In operation, assume that outlet pressure is below the pilot control setting. Control spring force on the pilot diaphragm thus opens the pilot valve plug providing additional loading pressure to the actuator diaphragm. This loading pressure forces the actuator stem forward, opening the main valve plug via a bump connection. The upward motion of the plug allows gas to flow through the cage into the downstream system. When downstream demand has been satisfied, outlet pressure will increase, acting on the pilot and actuator diaphragm. This pressure exceeds the pilot control spring setting, moving the pilot diaphragm away and letting the valve plug spring (Type 6351) or bellows (Types 6352 through 6354M pilots) close the pilot valve plug (unbalanced in the Type 6351 but balanced in the Types 6352 through 6354M pilots). Excess loading pressure on the actuator diaphragm escapes downstream through the bleed hole (Type 6351 pilot) or restriction (Types 6352 through 6354M pilots). Reduced actuator loading pressure permits the main valve to close. The combination of main valve spring force and valve plug unbalance provides positive valve plug shutoff against the port and upper seals. All 6350 Series pilots have an internal check valve that allows loading pressure to bleed downstream at approximately 25 psig / 1.7 bar differential across the actuator diaphragm.
Installation and Startup
-
Use qualified personnel when installing, operating and maintaining pilots. Before installing, inspect pilot and tubing, for any shipment damage or foreign material that may have been collected during crating and shipment. Make certain that body is clean and the pipelines are free of foreign material.
WARNING In hazardous or flammable gas service, vented gas may accumulate, and cause personal injury, death, or property damage due to fire or explosion. Vent a regulator in hazardous gas service to a remote, safe location away from air intakes or any hazardous location. The vent line or stack opening must be protected against condensation or clogging. -
To keep the pilot spring case vent from being plugged or the spring case from collecting moisture, corrosive chemicals, or other foreign material, point the vent down or otherwise protect it. To remotely vent the standard pilot, remove the vent and install obstruction-free tubing or piping into the 1/4 NPT vent tapping. Protect a remote vent by installing a screened vent cap into the remote end of the vent pipe.
-
Run a 3/8 in. / 9.5 mm outer diameter or larger pilot supply line from the upstream pipeline to the filter inlet. Do not make the upstream pipeline connection in a turbulent area, such as near a nipple, swage, or elbow. If the maximum pilot inlet pressure could exceed the pilot rating, install a separate reducing regulator in the pilot supply line. Install a hand valve in the pilot supply line, and provide vent valves to properly isolate and relieve the pressure from the regulator.
CAUTION Introduce pilot supply pressure into the regulator before introducing any downstream pressure, or internal damage may occur due to reverse pressurization of the pilot and main valve components. -
Pressure setting of pilot control spring: Turning the adjusting screw clockwise into the spring case increases the spring compression and pressure setting. Turning the adjusting screw counterclockwise decreases the spring compression and pressure setting.
Pilot Adjustment
To adjust standard 6350 Series pilots: loosen the locknut and turn the
adjusting screw. Then tighten the locknut to maintain the adjustment position.
A closing cap must be removed before adjustment and replaced afterwards.
WARNING To avoid possible personal injury from a pressure-loaded pilot, carefully vent the spring case before removing the closing cap. Otherwise, trapped loading pressure could forcefully eject the freed closing cap.
Maintenance
Pilot parts are subject to normal wear and must be inspected and replaced as
necessary. The frequency of inspection and replacement of parts depends upon
the severity of service conditions or the requirements of local, state, and
federal regulations. Due to the care Fisher™ takes in meeting all
manufacturing requirements (heat treating, dimensional tolerances, etc.), use
only replacement parts manufactured or furnished by Fisher.
All O-rings, gaskets, and seals should be lubricated with a good grade of general-purpose grease and installed gently rather than forced into position. Be certain that the nameplates are updated to accurately indicate any field changes in equipment, materials, service conditions, or pressure settings.
WARNING To avoid personal injury resulting from the sudden release of pressure, isolate the regulator from all pressure and cautiously release trapped pressure from the regulator before attempting disassembly.
Type 6351 Pilot
Perform this procedure if changing the control spring for one of a different
range, or if inspecting, cleaning, or replacing any other pilot parts. Pilot
key numbers are referenced in Figure 2.
Note The body assembly (key 1) may remain on the pipe nipple (key 22,
Figure 2) unless the entire pilot is replaced.
-
To gain access to the diaphragm assembly (key 7), control spring (key 9), or spring seat (key 8), loosen the locknut (key 11, and turn the adjusting screw (key 10) out until compression is removed from the spring. Remove the machine screws
(key 12), and separate the body assembly from the spring case. -
Inspect the removed parts and replace as necessary. Ensure the registration and bleed holes in the pilot body are free of debris. After assembly, make sure of the proper control spring setting according to the Startup section and remark the spring case if necessary.
-
To replace the valve plug (key 4), remove the body plug (key 3) to let the valve spring (key 6) and inner valve assembly (key 4) drop freely from the body (key 1). Inspect the removed parts, and replace if necessary. Make sure the plug seating surfaces are free from debris. Inspect body plug
- O- ring, replace if necessary. Type 6351 pilots manufactured before May 1999 need to have the body plug gasket and the body plug replaced with a new body plug assembly (key 3), which includes the body plug and the body plug O-ring. Install the body plug O-ring over the body plug. Stack the valve spring (key 6) and the inner valve assembly (key 4) on the body plug assembly (key 3), and install the body plug assembly with stacked parts into the body (key 1).
Types 6352 through 6354M Pilots
Perform this procedure if changing the control spring for one of a different
range, or if inspecting, cleaning, or replacing any other pilot parts. Pilot
part key numbers are referenced in Figure 3.
Note The body (key 1) may remain on the pipe nipple (key 21, Figure 3) unless the entire pilot is replaced.
-
To gain access to the diaphragm assembly (key 5), diaphragm limiter (key 23) if used, control spring (key 6), restriction (key 22), stem guide (key 8), or spring seat (key 7), remove the closing cap
(key 11), loosen the locknut (key 10), and turn the adjusting screw (key 9) counterclockwise until compression is removed from the spring. Remove the machine screws (key 14), and separate the body from the spring case (key 2). -
Inspect the removed parts, and replace as necessary. Make sure the restriction and the registration hole in the body are free from debris. After assembly, make sure of the proper control spring setting according to the Startup section, and remark the spring case if necessary.
-
To replace the valve plug (key 4) or bellows O-ring (key 17), remove the body plug (key 3) and body plug gasket (key 12). Be careful to keep the bellows assembly (key 16) from falling out and possibly getting lost while removing the valve plug. Inspect the removed parts, and replace as necessary. Make sure the valve plug seating surfaces are free from debris.
Parts Ordering
Each 6350 Series pilot is assigned a serial number or FS number which can be
found on the nameplates. Refer to this number when contacting your local Sales
Office for assistance, or when ordering replacement parts. When ordering a
replacement part, be sure to include the complete 11-character part number
from the following parts list. Some commonly used trim packages can be ordered
according to the 11-character assembly number given in the parts kits listed
in the Parts List.
Parts List
Type 6351 Pilot (Figure 2)
Types 6352, 6353, 6354L, 6354M, and 6354H Pilots (Figure 3)
The following parts are for Type 6353 only (not shown in Figure 3)
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D103153X012 © 2008, 2019 Emerson Process Management Regulator Technologies,
Inc. All rights reserved. 07/19. The Emerson logo is a trademark and service
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References
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