L91 Series
Modulating Controllers
Precision modulating and differential pressure controllers for stable industrial combustion and HVAC regulation.
What is the Honeywell L91 Series?
The Honeywell L91 Series is a family of modulating and differential pressure controllers designed for applications requiring precise pressure regulation rather than simple on/off control.
This series is commonly used in combustion systems, HVAC control loops, and industrial gas applications where stable pressure modulation improves system efficiency and safety.
How does the Honeywell L91 Series work?
L91 Series pressure controllers are widely applied in:
- Modulating burner control systems
- Gas and fluid pressure regulation
- Differential pressure safety monitoring
- HVAC and industrial combustion control loops
Control Specs
- Modulating Control
- Differential Sensing
- Combustion Precision
Key Differences
Key Differences & Selection
L91 Series models differ primarily in:
- Control Logic: Options for Modulating pressure control vs. On/Off switching.
- Sensing Type: Differential pressure sensing vs. single pressure point monitoring.
- Integration: Designed for integration with burner management and combustion control systems.
- Precision: Varying levels of precision and adjustment ranges for specific industrial needs.
Applications
- Modulating burner control
- Gas & fluid pressure regulation
- Differential pressure monitoring
- HVAC control loops
- Industrial combustion safety
Selection Guide
Modulating Control
Precise proportional pressure control for combustion and HVAC.
Pressure Switching
Reliable on/off switching for system monitoring.
Differential & Safety
Critical safety monitoring for pressure differences.
Model Comparison
L91 Series Model Comparison
| Model | Control Type | Pressure Function | Typical Use |
|---|---|---|---|
| L91A1151/U | Modulating Control | Pressure | Combustion systems |
| L91A1177/U | Advanced Modulating | Pressure | HVAC & combustion |
| L91B1035/U | Precision Switch | Pressure | Gas & fluid monitoring |
| L91B1050/U | Differential Control | Differential Pressure | Safety applications |
| L91B1068/U | Pressure Monitor | Pressure | HVAC & burner control |
| L91B1241/U | Industrial Switch | Pressure | Wide applications |
Frequently Asked Questions
What is the primary function of the Honeywell L91 Series?
The Honeywell L91 Series is designed to provide precise and reliable control for industrial combustion systems, ensuring optimal performance, safety, and energy efficiency across various heating applications.
How do I select the right model within the L91 Series?
Selecting the correct model depends on your specific application requirements, including operating voltage, required torque or capacity, and control logic (e.g., on-off vs. modulating). Refer to the model overview table above or contact our engineering team for technical assistance.
Are L91 Series components suitable for retrofitting existing systems?
Yes, Honeywell designs the L91 Series with standardization in mind, making them excellent choices for both new installations and retrofitting older or legacy combustion systems to meet modern safety and emissions standards.
All Models
Modulating Control
Pressure Switching
Differential & Safety
Need Precise Control?
Contact our engineering team for L91 Series modulating controller specifications.