Description
Honeywell MP904A5047 | Pneumatic Damper Actuator
Product Introduction
The Honeywell MP904A5047 is a pneumatic actuator designed to control dampers in heating, cooling, and ventilation systems. Rather than relying on an electric motor, it uses compressed air and a diaphragm mechanism to produce linear actuator movement, with a documented 90 mm stroke.
The A5047 configuration is particularly identifiable by its positioner and selectable pressure spans of 21, 35, and 70 kPa. That distinction matters when replacing older HVAC pneumatic controls: an MP904 family match alone is not sufficient because the pressure range, actuator force, stroke, and positioner configuration must correspond to the installed control loop.
Honeywell’s historical product documentation also shows MP904A5047 as the replacement type for several earlier MP904 pneumatic damper actuator models, confirming its role within the legacy Honeywell pneumatic control platform.
MP904A5047
Key Technical Specifications
- Manufacturer: Honeywell
- Model: MP904A5047
- Series: MP904
- Product category: Pneumatic damper actuator
- Actuation method: Pneumatic diaphragm
- Positioner: Included
- Stroke: 90 mm
- Maximum operating pressure: 140 kPa
- Maximum safe air pressure: 210 kPa
- Pressure range: 21 / 35 / 70 kPa, field-adjustable
- Effective diaphragm area: 146 cm²
- Net force at 0 kPa: 550 N
- Net force at 140 kPa: 600 N
- Air connection: Barb fitting
- Tubing: 6 mm / 1/4-inch polyethylene tubing
- Ambient temperature: −30 to +70°C
- Application: HVAC damper control
- Control medium: Compressed air
- Mounting/application: Damper actuator for heating, cooling, and ventilation systems
- Legacy status: Historical Honeywell product; replacement availability should be verified before procurement
The principal specifications above are supported by Honeywell’s field-device catalog.
Application Scenarios & Pain Points
HVAC Supply-Air Dampers
The MP904A5047 is designed for pneumatic control of dampers used in heating, cooling, and ventilation systems.
Its 90 mm stroke provides the mechanical travel required by compatible damper linkages and assemblies.
Variable-Air-Volume Systems
Older pneumatic VAV installations can contain MP904-series actuators that remain mechanically integrated with the original damper assembly.
Replacement issue: The actuator must be matched to the existing pneumatic controller and required pressure span. Substituting a visually similar actuator with a different operating range can change damper positioning.
Central HVAC Air-Handling Units
Air-handling equipment in older commercial and industrial facilities may use pneumatic control loops for damper modulation.
The MP904A5047’s positioner configuration makes the exact pressure-span selection an important part of commissioning.
Legacy Pneumatic Control Retrofits
Honeywell’s historical documentation identifies as a replacement type for several older MP904 actuator models. This makes it relevant when maintaining legacy pneumatic HVAC systems without immediately converting the entire control architecture to DDC/electronic control.
Industrial Ventilation Systems
Where pneumatic damper control remains in service, the actuator can be evaluated against the installed damper’s required force, travel, tubing connection, and pneumatic signal range.
QA & Live Testing SOP
For a procurement-grade , the following inspection sequence is recommended.
1. Model verification
Confirm the complete nameplate designation:
Do not accept an MP904-series match without checking the complete suffix.
2. Mechanical inspection
Inspect:
- Diaphragm housing
- Actuator body
- Rod/stem
- Mounting hardware
- Linkage connection
- Positioner mechanism
- Air fitting
- Tubing connection point
Look for corrosion, cracked components, damaged threads, or evidence of diaphragm deterioration.
3. Pneumatic leak test
Connect a regulated air source using suitable tubing and fittings. Increase pressure gradually while monitoring the actuator for abnormal leakage.
Do not exceed the documented 140 kPa operating pressure during normal functional testing.
4. Stroke verification
Verify approximately 90 mm actuator travel and confirm smooth movement without sticking or mechanical interference.
5. Pressure-span verification
Check the configured positioner range against the required installation:
- 21 kPa
- 35 kPa
- 70 kPa
The selected range should correspond to the control system and damper application.
6. Force/response check
Verify that actuator movement remains stable across the intended pressure range. Investigate excessive hysteresis, sluggish movement, leakage, or failure to reach the expected position.
7. Damper coupling check
When installed, verify that the actuator reaches the required damper positions without mechanical overtravel or linkage binding.
8. Documentation
Record:
- Exact model
- Serial/identification information
- Pressure range
- Stroke
- Pneumatic test pressure
- Leakage observations
- Mechanical condition
- Positioner response
This is a recommended QA and live-testing SOP, not a claim that any particular unit has already been tested.
Field Engineer’s Pitfall Guide
❗ Do not confuse the pressure range with maximum operating pressure.
The has selectable pressure spans of 21, 35, and 70 kPa, while its maximum operating pressure is 140 kPa. These are different specifications.
❗ Verify the positioner configuration.
Honeywell specifically identifies the A5047 version with a positioner. A visually similar actuator may have a different configuration.
❗ Do not exceed the safe pneumatic limit.
Honeywell documents 210 kPa maximum safe pressure and 140 kPa maximum operating pressure. Normal control operation should remain within the specified operating limit.
❗ Check the tubing before blaming the actuator.
A leaking 6 mm / 1/4-inch pneumatic line, restricted tubing, incorrect fitting, or unstable controller output can produce symptoms that look like actuator failure.
❗ Verify mechanical force requirements.
The published actuator force is approximately 550 N at 0 kPa and 600 N at 140 kPa. The actual damper linkage must be checked for friction, binding, leverage, and required operating force.
❗ Confirm stroke and linkage geometry.
The actuator provides 90 mm of stroke. A damper linkage designed for a different travel can produce incomplete opening/closing even when the pneumatic actuator itself is functioning correctly.
❗ Treat the exact part number as procurement-critical.
Honeywell’s historical documentation identifies as a replacement for several older models, but that does not mean every variant is interchangeable without checking the pneumatic and mechanical requirements.
Intent-Driven FAQ
What is Honeywell ?
The is a pneumatic damper actuator with a positioner for HVAC damper applications. Honeywell specifies it within the pneumatic actuator family.
What is the stroke of ?
The documented stroke is 90 mm.
What pressure does use?
The A5047 configuration has field-adjustable pressure spans of 21, 35, and 70 kPa. Its maximum operating pressure is 140 kPa, with 210 kPa listed as the maximum safe pressure.
Does include a positioner?
Yes. Honeywell’s catalog specifically identifies the configuration with a positioner.
What tubing does use?
The specified air connection is a barb fitting for 6 mm / 1/4-inch polyethylene tubing.
What force can produce?
Honeywell documents an effective diaphragm area of 146 cm², with net force of approximately 550 N at 0 kPa and 600 N at 140 kPa.
What temperature range is specified?
The documented ambient operating range for the A5047 configuration is −30°C to +70°C.
Is still a current product?
Honeywell historical documentation treats the family as an older product line, and current market references identify . Therefore, procurement should verify exact stock condition and replacement compatibility rather than assuming ongoing OEM production.
What should I verify before purchasing ?
Confirm the complete part number, pressure range, positioner configuration, 90 mm stroke, pneumatic tubing connection, damper linkage geometry, required operating force, and available compressed-air pressure. Those parameters determine whether the actuator is actually suitable for the installed control loop.
