Honeywell L91 Series
Modulating Pressure Control

L91 Series
Modulating Controllers

Precision modulating and differential pressure controllers for stable industrial combustion and HVAC regulation.

Series Overview

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.

Functional Role in Control Systems

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
L91 Modulating Controller
Pressure Regulation

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

Model Comparison

L91 Series Model Comparison

ModelControl TypePressure FunctionTypical Use
L91A1151/UModulating ControlPressureCombustion systems
L91A1177/UAdvanced ModulatingPressureHVAC & combustion
L91B1035/UPrecision SwitchPressureGas & fluid monitoring
L91B1050/UDifferential ControlDifferential PressureSafety applications
L91B1068/UPressure MonitorPressureHVAC & burner control
L91B1241/UIndustrial SwitchPressureWide applications

Selection Guide

  • L91A models: Preferred for modulating pressure control applications.
  • L91B models: Used for precision monitoring or differential pressure safety.
  • Integrated variants: Selected for complex gas or liquid pressure systems.

Need Precise Control?

Contact our engineering team for L91 Series modulating controller specifications.