The Fisher 299H-MBL/D7 command-operated pressure reducing regulator (New Part Number: 299H-1131-5262032) is a high-performance gas pressure control solution designed and manufactured by Emerson Process Management. This versatile regulator is specifically engineered for natural gas, manufactured gas, liquefied petroleum gas (LPG), and air applications, making it the ideal choice for direct-fired equipment and industrial burner systems.
Fisher 299H-MBL/D7 Actual Product Image
Model Identification: 299H-MBL/D7 (299H-1131-5262032)
| Code Segment | Description | Specification |
|---|---|---|
| 299H | Product Family | Command-Operated Pressure Reducing Regulator |
| M | Body Material | Ductile Iron (Cast Iron) |
| B | Connection Type | NPT Internal Thread |
| L | Orifice Size | 1-3/16 inch (30mm) |
| /D7 | Spring Range | 2.75-6 PSI Outlet Pressure |
New Part Number: 299H-1131-5262032 (replaces legacy 299H-MBL/D7)
Technical Specifications
Pressure Ratings
| Parameter | Value |
|---|---|
| Maximum Inlet Pressure | 80 PSI (5.5 bar) |
| Outlet Pressure Range | 2.75-6 PSI (0.19-0.41 bar) |
| Operating Temperature | -20°F to 150°F (-29°C to 66°C) |
| Emergency Outlet Pressure | 7.25 PSI maximum |
Physical Specifications
| Parameter | Specification |
|---|---|
| Body Size | DN50 (2 inch NPT) |
| Orifice/Valve Port Size | 1-3/16″ (30mm) |
| End Connection | 2″ NPT Internal Thread |
| Body Material | Ductile Iron (ASTM A536) |
| Approximate Weight | 14 kg (31 lbs) |
| Flow Direction | Straight-through |
Flow Capacity
| Inlet Pressure | Outlet Pressure | Natural Gas Flow (SG=0.6) |
|---|---|---|
| 10 PSI | 3.5 PSI | 4,500 SCFH |
| 20 PSI | 3.5 PSI | 6,800 SCFH |
| 40 PSI | 3.5 PSI | 9,200 SCFH |
| 60 PSI | 3.5 PSI | 11,500 SCFH |
| 80 PSI | 3.5 PSI | 13,200 SCFH |
Flow capacities based on 1-3/16″ orifice with 20% droop
Material Specifications
Component Materials
| Component | Material | Specification |
|---|---|---|
| Main Valve Body | Ductile Iron | ASTM A536 Grade 65-45-12 |
| Pilot/Command Body | Aluminum Alloy | Die-cast aluminum |
| Spring Housing | Aluminum Alloy | Die-cast aluminum |
| Valve Plug/Disc | Aluminum Alloy | Hard-anodized |
| Valve Seat | Aluminum | Buna-N (Nitrile) rubber insert |
| Main Spring | Steel | Zinc-plated |
| Diaphragm | Buna-N (Nitrile) Rubber | Fabric-reinforced |
| Diaphragm Plate | Steel | Zinc-plated |
| Seals & Gaskets | Buna-N (Nitrile) Rubber | Standard service |
| Fasteners | Steel | Zinc-plated |
Key Features & Performance Characteristics
Sensitive Shutoff Capability
The Fisher 299H incorporates a precision-machined valve plug and seat design that provides bubble-tight shutoff when flow demand ceases, minimizing gas waste and ensuring safety in burner applications.
Simple Pressure Setting
External adjustment screw allows easy outlet pressure setting without disassembling the regulator. Lock nut secures setting against vibration-induced changes.
High Regulation Accuracy
Command-operated design delivers superior accuracy compared to direct-operated regulators:
- Accuracy Class: ±2.5% of absolute outlet pressure
- Droop Characteristic: Minimal deviation across flow range
In-Line Serviceability
Modular construction enables maintenance without removing regulator from pipeline:
- Replaceable seat and plug assembly
- Accessible diaphragm and springs
- Field-replaceable pilot components
Fast Response Time
Optimized pilot volume and flow paths provide rapid response to flow demand changes, essential for direct-fired burner applications where flame stability is critical.
Versatile Gas Compatibility
| Gas Type | Compatibility | Notes |
|---|---|---|
| Natural Gas | ✓ Standard | Primary application |
| Manufactured Gas | ✓ Standard | Town gas, coke oven gas |
| LPG (Propane/Air) | ✓ Standard | Vapor phase only |
| Air | ✓ Standard | Clean, dry air recommended |
| Nitrogen | ✓ Acceptable | Inert gas applications |
Application Industries
Commercial & Industrial Burners
- Direct-fired air heaters
- Industrial ovens and furnaces
- Process heaters
- Boiler burners
- Incinerators
Food Service Equipment
- Commercial kitchen ranges
- Bakery ovens
- Food processing equipment
- Steam generators
Agricultural Applications
- Crop dryers
- Livestock heating systems
- Greenhouse heating
Other Applications
- Gas engine fuel systems
- Generator sets
- Kilns and dryers
- Heat treating equipment
Installation Guidelines
Mounting Position
- Preferred: Upright (spring housing vertical)
- Acceptable: Horizontal or inclined (avoid inverted mounting)
- Clearance: Minimum 12″ (300mm) for adjustment access
Piping Requirements
- Use full-port valves upstream and downstream
- Install sediment trap/drip leg upstream
- Provide pressure taps for inlet/outlet pressure measurement
- Use pipe dope compatible with Buna-N seals
Sizing Considerations
- Size for maximum anticipated flow at minimum inlet pressure
- Allow 10-20% safety margin for future capacity needs
- Consider pressure droop at high flow conditions
Venting Requirements
- Pilot exhaust must be vented to safe atmosphere
- Use vent line minimum 1/2″ diameter
- Protect vent opening from contamination
Maintenance & Troubleshooting
Routine Maintenance Schedule
| Interval | Action |
|---|---|
| Monthly | Visual inspection for leaks |
| Quarterly | Check and record outlet pressure |
| Annually | Internal inspection, seal replacement |
| As needed | Diaphragm and spring inspection |
Common Issues & Solutions
| Symptom | Probable Cause | Solution |
|---|---|---|
| Outlet pressure high | Worn seat/plug | Replace seat assembly |
| Outlet pressure low | Plugged pilot orifice | Clean pilot filter |
| Pressure hunting | Oversized regulator | Verify sizing calculations |
| External leakage | Worn diaphragm | Replace diaphragm assembly |
| Slow response | Contaminated pilot | Clean and inspect pilot |
Why Choose Genuine Fisher 299H?
| Advantage | Benefit |
|---|---|
| Emerson Quality | 130+ years of pressure control expertise |
| Global Availability | Worldwide service and parts support |
| Proven Design | Millions of units in service globally |
| Safety Certified | CSA, UL, and CE approved configurations |
| Interchangeable Parts | Common components reduce inventory |
| Technical Support | Factory-trained service network |
Ordering Information
The Fisher 299H pressure regulator is available in multiple configurations:
| Configuration | Part Number |
|---|---|
| Standard (2.75-6 PSI) | 299H-1131-5262032 |
| Low Pressure (1-2.5 PSI) | 299H-1131-5262033 |
| High Pressure (5-12 PSI) | 299H-1131-5262034 |
| With Internal Relief | 299H-1131-5262035 |
Standard Package Includes:
- Fisher 299H regulator assembly
- Installation instructions
- Nameplate with specifications
- Factory test certificate
