Page 1 of 12WAUKESHA ENGINE DRESSER, INC. WAUKESHA, WI 53188-4999
SUBJECT: Mooney Fuel Regulators
MODELS AFFECTED: VHP GSI/GL/LT
SERVICE BULLETINTOPIC: Fuel System
IDENT NO: 9-2916SUPERSEDES: New
DATE: April 15, 2003
INTRODUCTION
Mooney regulators are now used on select VHP engines. The new regulator will be standard equip- ment on all GSI, GL, and LT engines running on pipe- line quality or 900 Btu field gas. It is currently not used with GLD, GSID or AFM equipped engines. The new regulator provides improved control and ease of main- tenance.
PRINCIPLES OF OPERATION
The Mooney regulator system utilizes a pilot that con- trols a main valve (see Figure 1 and Figure 3). The pilot assembly features a removable cartridge and a10 micron gas filter. The main valve is a simple design that uses few parts. These features make the regula- tor assembly easy to maintain.
diaphragm is closed tightly against the throttle plate. The pressure differential across the outlet half of the diaphragm adds to the spring force in closing the valve.
As demand for flow occurs in the downstream system, the outlet pressure drops causing the pilot valve to open and start bleeding pressure out of the spring case faster than it can enter through the cartridge restrictor, resulting in a reduction of pressure above the diaphragm (see Figure 2). This allows the inlet pressure to progressively lift the main valve diaphragm off the throttle plate, opening the valve and satisfying the demand for flow in the downstream system.
PILOT SENSE CONNECTION
PILOT SUPPLY
PILOT SENSE CONNECTION
PILOT
PILOT SUPPLY
RESTRICTOR
CONTROLPRESSURE
RESTRICTOR
PILOT VALVE
PILOT LOADING CONNECTION
PILOT LOADING CONNECTION
MAIN VALVEINLET
PILOT OUTLET CONNECTION
OUTLET
INLET
PILOT OUTLET CONNECTION
OUTLET
DIAPHRAGM Figure 2. Pressure Reducing Configuration Fully Open
When demand for flow ceases or is reduced, the downstream pressure increases causing the pilot
Figure 1. Pressure Reducing ConfigurationFully Closed
At no flow, when the outlet pressure is greater than the set point of the pilot, the pilot valve is closed and full inlet pressure loads the spring case through the pilot loading connection. In this condition the main
valve
Page 2 of 12 WAUKESHA ENGINE DRESSER, INC. WAUKESHA, WI 53188-4999
valve to close. Inlet pressure continues to pass through the restrictor until the control pressure equals the inlet pressure. The spring force, plus the pressure differential across the outlet half of the main valve dia- phragm, closes the diaphragm against the throttle plate, shutting off the flow.
Service Bulletin No. 9-2916
PILOT OUTLET CONNECTION PILOT SENSE
CONNECTION
PILOT INLET (SUPPLY) CONNECTION CARTRIDGE
FIXED RESTRICTOR
ORIFICEOUTLET
VENT
PILOT
PILOT LOADING
CONNECTIONFILTER
MAIN VALVE
INLET
Figure 3. Inline Regulator (Left Bank)
MAINTENANCE SCHEDULE
1. Once a year replace seals, O-rings, diaphragms and filter element (see Table 1 and Table 2).
2. Inspect and clean fixed restrictor orifice located in pilot inlet supply connection (see Figure 3 and Figure 4). Orifice inside diameter is 0.052 in. (1.3 mm) (#55 drill).
NOTE: Pilot parts are subject to normal wear and must be inspected and replaced as necessary. The frequency of inspection and replacement of parts depends on severity of service conditions and/or the requirements of local, state, and federal regulations. Be certain that the name plates are updated to accurately indicate any field changes in equipment, materials, service conditions, or pressure settings.
3. Inspect all other components (replace as needed).
INSIDE DIAMETER0.052 IN. (1.3 MM)
Figure 4. Fixed Restrictor Orifice
ORIFICE
P/N DESCRIPTION
489669Pilot Maintenance Kit (Pivot Assembly O-
ring, Diaphragm, Closing Cap O-ring, Adjusting Assembly O-ring)
489667
Cartridge Assembly Maintenance Kit (Bottom Cap O-ring, Plug and Stem
Assembly, Orifice O-ring, Lower Body Insert O-ring, Upper BodyInsert O-ring, Stem O-ring)
489670 1.5 in. Main Valve Maintenance Kit
4896711.5 in. Main Valve Overhaul Kit (Low Differential Main Spring, Diaphragm,
Throttle Plate, Body Seal)
489666 Type 30A Filter Maintenance Kit (Element and O-ring)
P/N DESCRIPTION
214172 Pilot
489668 Cartridge
214174 Filter
214171 Main Valve (RB)
214171A Main Valve (LB)also used on inline engines
214175 Fixed Restrictor Orifice
REPLACEMENT SERVICE PARTS AND KITS
Table 1. Component Assemblies
Table 2. Service Part Kits
(Diaphragm and Body Seal)
Table 3. Mooney Regulator Fuel Pressures
ENGINE MODELRECOMMENDED NATURAL GAS SUPPLY PRESSURE TO ENGINE
MOUNTED REGULATOR
MAXIMUM NATURAL GAS SUPPLY PRESSURE TO ENGINE MOUNTED
REGULATOR
F2895GSI; F3521GSI; L5790GSI; L7042GSI; P9390GSI 24 - 50 psig (165 - 345 kPa) 75 psig (517 kPa)
F3524GSI; L5794GSI; L7044GSI 24 - 50 psig (165 - 345 kPa) 75 psig (517 kPa)
F2895GL; F3521GL; L5790GL; L7042GL; F9390GL 38 - 60 psig (262 - 414 kPa) 75 psig (517 kPa)
L5794LT; L5774LT 43 - 60 psig (296 - 414 kPa) 75 psig (517 kPa)
REGULATOR ADJUSTMENTS
The Mooney regulators were designed to track similar to the previous Fisher regulator. The gas/air setting and carburetor adjustments will remain the same as those used with the Fisher regulator. Mooney regula- tors require specific supply pressures depending on engine model (see Table 3).
The gas over air adjustment is controlled by adjusting the stem screw and lock nut located at the bottom of the pilot assembly. Turning the stem screw clockwise will increase spring tension increasing the gas/air. Turning the screw counterclockwise will reduce spring tension and reduce the gas/air setting. Initial setting is a stem length of approximately 2.75 in. (6.98 cm) measured from adjuster housing fitting (see Figure 19).
PILOT
DISASSEMBLE PILOT
WARNINGBefore disassembly make sure the regulator and main valve have been isolated from the process by closing block valves on the inlet and outlet sides of each component. Safely release pressure and process fluid from the valve body and pilot system. Failure to properly complete these
steps may result in personal injury and/or property damage.
NOTE: A spare cartridge may be installed and the regulator returned to service if time is a factor. Make sure the stem O-ring is still in place in the pilot body before installing the new cartridge. If the O-ring was removed, install a new O-ring over the stem of the cartridge assembly prior to installing it in the pilot body (see Figure 5 and Figure 6).
1. Depressurize pilot and main valve. Unscrew and remove cartridge (see Figure 5).
CARTRIDGE
Figure 5. Cartridge Assembly
2. Remove stem O-ring from pilot body using suitable tool (a paper clip works well). Do not scratch O-ring groove (see Figure 6).
NOTE: The loading and inlet ports are interchangeable with one another. OUTLET RETAINER
PLUG
LOADING INLET
LOADING
INLET
OUTLET STEM O-RING
5/16 IN.-18 UNC CAPSCREW
Figure 6. Stem O-ring
3. Remove bottom cap from cartridge body and remove internal parts. Use a heavy paper clip or0.045 in. (1.14 mm) diameter wire to push out orifice assembly (pilot valve). Do not damage O-ring sealing surface of body cartridge (see Figure 7).
CARTRIDGE BODY
LOCK NUTSPRING
ADJUSTER STEM
Figure 8. Pilot Spring Barrel
7. Thread 5/16 in. - 18 UNC capscrew into pivot and pull pivot and lever assembly out of pilot body (see Figure 9).
5/16 IN.-18 UNC CAPSCREW
ORIFICE ASSEMBLY
BOTTOM CAP ASSEMBLY
Figure 7. Cartridge Assembly
4. Loosen lock nut on spring adjuster stem. Unscrew adjuster stem. Spring tension will release as stem is unscrewed (see Figure 8).
5. Remove retainer plug located below outlet port(see Figure 8).
6. Remove one 5/16 in. - 18 UNC capscrew that secures spring case to pilot body (see Figure 8).
Figure 9. Pivot And Lever Assembly Removal
8. Remove remaining capscrews that secure spring case to pilot body. Separate spring case from pilot body (see Figure 10).
PILOT BODYASSEMBLE PILOT
NOTE: Use Parker Super O-Lube or an equivalent silicone based lubricant on all O-rings in the pilot assembly.
1. Apply Parker Super O-Lube and slide O-ring onto pivot and lever assembly. Apply Lubriplate No. 105 petroleum grease to roll pin and lever (see Figure 13).
ROLL PIN
SPRING CASE
Figure 10. Spring Case And Pilot Body
9. Disconnect line connections and remove pilot body(see Figure 11).
PILOT BODY
LEVER O-RING
Figure 13. Pivot And Lever Assembly
2. Install pilot diaphragm with convex side toward diaphragm plate and main spring. Secure with nut and washer. Tighten to 5 - 6 ft-lbs (6.8 - 8.2 N m). Do not overtighten, overtightening will distort the pilot diaphragm (see Figure 14).
Figure 11. Pilot Body
10. Remove diaphragm assembly from body. Remove retaining nut and remaining components. Inspect all parts for wear or damage (see Figure 12).
DIAPHRAGM PLATE
NUT
WASHER
RETAINING NUT DIAPHRAGMDIAPHRAGM
DIAPHRAGM RETAINER
Figure 14. Pilot Diaphragm
3. Thread 5/16 in. - 18 UNC capscrew into pivot then push pivot and lever assembly into pilot body. A guide pin located at the bottom assures pivot and lever assembly is correctly oriented in body. Remove capscrew when complete (see Figure 15).
Figure 12. Diaphragm Assembly
SPRING WASHER
5/16 IN.-18 UNC CAPSCREW
GUIDE PIN NOTCH
Figure 15. Pivot And Lever Assembly
4. Install retainer plug into body. Plug should be flush with body when installed correctly (see Figure 8).
5. Slide diaphragm assembly onto lever. Align diaphragm with pivot and lever assembly. Lubrication of pivot pin is not required (see Figure 16).
LEVER
Figure 17. Diaphragm Spring Washer
7. Place spring case on pilot body (see Figure 18).Vent connection should face down when regulator is mounted on engine. This allows condensation to drain away instead of accumulating and possibly freezing.
8. Secure spring case to pilot body with cap screws.Tighten in a criss cross pattern to 5 ft-lbs (6.8 N m) (see Figure 18).
9. Install main spring (brown) into spring case.
NOTE: The top of the main spring will be almost 2.0 in. (5.0 cm) below the spring case when fully installed.
SPRING CASE MAIN SPRING
DIAPHRAGM
Figure 16. Diaphragm Installation
6. Place spring washer onto diaphragm plate.Lubricate spring washer with Lubriplate No. 105or petroleum grease to hold in position (see Figure 17). Washer prevents main spring from “binding” on diaphragm assembly when compressed.
VENT
Figure 18. Spring Case
10. Install O-ring on spring adjuster fitting (see Figure 19). Screw adjuster stem out to relieve spring pressure during installation.
11. Install adjuster fitting in body. Turn adjuster stem until it measures 2.75 in. (6.98 cm) from adjuster fitting. Tighten lock nut (see Figure 19 and
Figure 20).
2.75 IN. 6.98 CM STEM O-RING
O-RINGS
O-RING
ADJUSTER STEM
BODY INSERT
Figure 19. Spring Adjuster Assembly
ADJUSTER FITTING BACK-UP
WASHER
ORIFICE O-RING
ORIFICE
LOCK NUT ADJUSTER STEM
PLUG AND STEM ASSEMBLY
Figure 20. Spring Adjuster
NOTE: A spare cartridge may be installed and the regulator returned to service if time is a factor. Make sure the stem O-ring is still in place in the pilot body before installing the new cartridge. If the O-ring was removed, install a new O-ring over the stem of the cartridge assembly prior to installing it in the pilot body (see Figure 5 and Figure 6).
12. Assemble cartridge by placing O-ring on bottom cap, then install return spring, orifice spring, stem guide, plug and stem, orifice and O-ring, and back- up washer (see Figure 21).
STEM GUIDE
RETURN SPRING
ORIFICE SPRING
O-RING
BOTTOM CAP
Figure 21. Cartridge Assembly
13. Install bottom cap assembly into body insert.Return spring will force orifice into position as cap assembly is screwed into body insert (see Figure 22). Tighten to 5 ft-lbs (6.8 N m).
CARTRIDGE
BODY INSERT
BOTTOM CAP ASSEMBLY
O-RING O-RING
Figure 24. Cartridge Assembly
FILTER MAINTENANCE
The filter element is subject to plugging and must beFigure 22. Cartridge Body and Cap Assembly
14. Press stem against hard surface to verify it moves freely and returns to extended position. Stem should extend 0.32 in. (8.1 mm) from body insert (see Figure 23).
STEM0.32 IN.
(8.1 MM)
inspected and replaced as necessary. The frequency of inspection and replacement of the filter element depends on severity of service conditions and the length of time in service.
WARNINGBefore disassembly make sure the regulator and filter have been isolated from the process by closing block valves on the inlet and outlet sides of the regulator. Safely release pressure and process fluid from body and pilot system. Failure to properly complete these steps may result in personal injury and property damage.
BODY INSERT
DISASSEMBLE FILTER
1. Depressurize main valve and filter. Remove filter housing (see Figure 25).
Figure 23. Cartridge Stem Height
15. Apply Parker Super O-Lube and slide O-ring onto stem.
16. Verify O-ring is lubricated and in position on stem.Install cartridge into pilot body. Tighten to 5 ft-lbs (6.8 N m). Do not overtighten (see Figure 6 and Figure 24).
FILTER HOUSING
Figure 25. Filter Assembly
2. Inspect filter element and replace if necessary(see Figure 26).
FILTER
FILTER HOUSING
Figure 26. Filter Element
FILTER HOUSING Figure 28. Filter Assembly
MAIN VALVE MAINTENANCE
3. Remove filter O-ring (see Figure 27). A paper clip or other suitable tool can be used. Inspect for defects and replace if necessary.
O-RING
Figure 27. Filter Fitting
ASSEMBLE FILTER
1. Lubricate O-ring with Parker Super O-Lube (or equivalent petroleum based lubricant) and install in filter fitting.
NOTE: If the filter guide is removed, apply a small quantity of Loctite (or equivalent) to the threaded area and screw hand tight into filter body.
2. Lubricate threads of filter housing with Lubriplate(or equivalent petroleum based lubricant).
3. Place filter element into housing. Screw housing into fitting and tighten to 5 ft-lbs (6.8 N m). Do not overtighten (overtightening an O-ring joint will not improve seal). Element will guide itself into
position regardless of orientation.
Main valve parts are subject to normal wear and must be inspected and replaced as necessary. The fre- quency of inspection and replacement of parts depends on severity of service conditions and/or the requirements of local, state, and federal regulations. Be certain that the name plates are updated to accu- rately indicate any field changes in equipment, materi- als, service conditions, or pressure settings.
WARNINGBefore disassembly make sure the main valve has been isolated from the process by closing block valves on the inlet and outlet sides of the main valve. Safely release pressure and process fluid from body and pilot system. Failure to properly complete these steps may result in personal injury and property damage.
DISASSEMBLE MAIN VALVE
1. Disconnect pilot loading line from pilot (seeFigure 29).
2. Remove two 5/16 in. - 18 UNC capscrews that secure main valve bracket to pilot (see Figure 29).
3. Loosen valve cover capscrews in a criss-cross pattern. The main spring will lift the cover as capscrews are removed (see Figure 29).
VALVE COVER OUTSIDE RIB DOWNSTREAM
PILOT LOADING LINE
5/16 IN.-18 UNC CAPSCREWS CAPSCREW
Figure 29. Pilot Loading Line
4. Remove main spring, diaphragm, and cover (seeFigure 30 and Figure 33). Inspect parts for wear.
Figure 31. Throttle Plate
5. Remove and inspect nitrile body seal for wear or damage (see Figure 32).
MAIN SPRING
COVERDIAPHRAGM
NITRILE BODY SEAL
Figure 30. Main Valve Cover
NOTE: Shutoff occurs at the downstream outside “rib” located on the throttle plate. The outside edge of the downstream (outlet) portion is the primary shutoff surface and should be inspected more closely for wear and damage. Nicks and/or wear on support ribs will usually not affect shutoff (see Figure 31).
Figure 32. Nitrile Body Seal
6. Inspect all parts for wear and damage. Replace as necessary.
CLEANING MAIN VALVE
1. Do not clean body seal grooves with sharp metal tools. Bottom of groove and mating surface of adjacent parts must have smooth finish to prevent leakage.
ASSEMBLE MAIN VALVE
COVER
1. Install nitrile body seal (see Figure 34 andFigure 34).
BOSS
MAIN SPRING
DIAPHRAGM
NITRILE BODY SEAL
Figure 34. Nitrile Body Seal
THROTTLE PLATE NOTE: If the inlet sides of the throttle plate and diaphragm are in better condition than the outlet sides, the entire assembly can be rotated 180 degrees (outlet to inlet) to renew the shutoff capability (see Figure 35).
OUTLET SIDES
NITRILE BODY SEAL
INLET
BODY
INLET SIDES
FLOW DIRECTION OUTLET
Figure 35. Throttle Plate
2. Place spring on diaphragm. Spring case (cover)fits on top of spring. Do not lubricate diaphragm
Figure 33. Left Bank/Inline Main Valve Configuration
NOTE: The cover plate should be positioned so the boss is located at the outlet (downstream) side of the fuel line (see Figure 33 and Figure 38).
NOTE: The nitrile rubber body seal can swell after disassembly of a main valve that has been in service (due to gas permeating the nitrile rubber). This does not necessarily mean it must be replaced. However, before placing the seal back into service inspect for defects. Set seal aside for several hours and it will
gradually return to normal size. Placing seal(s) on ice will speed the process considerably.
sealing surface (see Figure 33 and Figure 36).
MAIN SPRING5. Tighten spring case cover capscrews in
increments using a criss-cross pattern (see Figure 38 and Figure 39). Tighten to 20 ft-lbs (27 N m).
6. Install pilot loading line (see Figure 38).
BRACKET COVER CAPSCREW
COVER DIAPHRAGM
Figure 36. Main Valve Cover
NOTE: The cover plate should be positioned so the boss is located at the outlet (downstream) side of the fuel line (see Figure 33 and Figure 37).
PILOT LOADING LINE
5/16 IN.-18 UNC CAPSCREW
3. Place spring case cover assembly and bracket on main valve and secure with four capscrews (see Figure 38). Do not fully tighten.
Figure 38. Inline/Left Bank Main Valve
COVER CAPSCREW
BOSS OUTLET
BRACKETINLET FLOW
DIRECTION
Figure 37. Inline/Left Bank Main Valve
4. Secure opposite end of bracket to pilot body with5/16 in. - 18 UNC capscrews (see Figure 38).
Lubricating or over-
COVER CAPSCREW
PILOT LOADING
CAUTION tightening valve coverLINE
capscrews can damage the diaphragm. Disregard- ing this information could result in severe engine damage.
Do not replace the
Figure 39. Right Bank Regulator
7. Reconnect pilot system. Follow approved start up procedures when returning to operation.
CAUTION studs or nuts with anycapscrew or stud and nut combination that does not have an SAE Grade 7 or ASTM Grade B7 rat-
ing. Disregarding this information could result in severe engine damage.