STATIC-PRESSURE-TIPS-ACCESSORIES

Supported Applications

The Dwyer Static Pressure Tips and Accessories series provides sensing solutions for static pressure in ducts, rooms, clean environments, and outdoor locations. These accessories are designed to interface with differential pressure switches, transmitters, Magnehelic® Gages, VAV units, and other pressure-sensing devices.

Documented applications include:

• HVAC Systems: Building pressurization control using outdoor static pressure as a reference; return/exhaust fan controls; zone return air dampers.
• Clean Environments: Sensing space pressures in clean rooms, laboratories, and building lobbies where filtered sensing is required (e.g., 60 micron filters).
• Duct Monitoring: Measuring static air pressure in ducts for applications requiring differential pressure across a filter or coil.
• Outdoor Sensing: Reducing fluctuations caused by wind gusts to provide stable atmospheric pressure readings at building sites.

Operating Conditions & Performance

The series is engineered for accurate static pressure sensing in smooth air velocities up to 1500 FPM. While specific performance metrics such as accuracy class or response time are not provided in the source documentation, the design focuses on minimizing dynamic pressure errors and ensuring stable readings.

• Velocity Capability: Accurate static pressure sensing in smooth air at velocities up to 1500 FPM.
• Error Reduction: Outdoor models (e.g., A-306, A-420A) are designed to reduce wind-induced dynamic pressure errors and fluctuations caused by gusts when mounted parallel to the ground or earth's surface.
• Filtration: Specific room-mount models incorporate 60 micron filters or fine mesh screens to prevent debris from obstructing the sensing port, ensuring clean connections for tubing.

Installation Guidelines

To maintain measurement integrity, specific mounting constraints are documented for outdoor and space sensors:

• Turbulence Avoidance: Position sensors as far as possible from sources of turbulence such as trees, chimneys, signs, buildings, economizers, intake/exhaust fans, or barometric dampers.
• Clearances: Mount outdoor units at least 24 inches from the wall and at least 12 inches above surrounding obstacles. Do not mount under awnings within fifteen feet or near building corners.
• Orientations: Outdoor units should be mounted with the plate parallel to the earth's surface; vertical mounting may yield incorrect readings if wind is not blowing within 15 to 20 degrees of the opening direction.

Configuration Options

The series encompasses a broad range of configurations tailored for duct, wall, ceiling, and outdoor installations. Variants differ by mounting style, insertion depth, material composition (stainless steel vs. plastic), and connection types.

Duct Static Pressure Tips

• Mounting Styles: Hook-style tips with mounting flanges (A-302F series) and straight static pressure tips with mounting flanges (A-489, A-491, A-493).
• Insertion Depths: Available in 4", 6", 8", and 12" lengths depending on the model.
• Materials: Stainless steel (SS) options are available for durability; standard models may utilize other materials as specified by part number suffixes (e.g., -SS).

Room & Space Pressure Sensors

• Clean Room Models: A-417A and A-414 feature 60 micron filters for clean room applications.
• Wall Mounts: Units like the A-418E, A-418N, and A-465 fit standard single gang electrical boxes (2" x 4") or sheetrock walls. The A-465 includes a block-free pressure reference opening.
• Ceiling Mounts: Models such as the A-419A rest on top of standard 3/4" thick ceiling tiles with filters facing down through a 5/8" hole.

Outdoor & Specialized Accessories

• Outdoor Sensors: The A-306 and A-306-A include the sensor, mounting bracket, hardware, and 50' of vinyl tubing. Longer lengths are available on special order.
• Duct Tips with Dampers: Model A-421 includes a built-in surge damper to ensure stable readings; an optional pressure spike reducer can be added for further smoothing.

Process Connections

The series supports various tubing and conduit connections, including:

• Tubing Fittings: Barbed fittings compatible with 1/8" to 3/16" ID plastic or rubber tubing; compression fittings for 1/4" metal tubing.
• Pipe Threads: Models such as A-305 and A-305-SS feature a 1/8" NPT male pipe thread connection.
• Conduit Fittings: Outdoor models like the A-420A include a 1/2" EMT conduit fitting for electrical connections.

Housing Materials

Materials vary by application environment, including ABS plastic enclosures (e.g., A-465), stainless steel wall plates and tips, and structures designed to withstand harsh environmental elements for outdoor use.

Key Product Differences

The series is organized into distinct model families based on installation location and sensing requirements:

• A-301 / A-305 Series: Static pressure tips designed for duct mounting with 1/4" metal tubing connections or 1/8" NPT pipe threads. Variants include different insertion depths (6", 8", 12") and stainless steel options.
• A-302 / A-307 Series: Tips and fittings for plastic/rubber tubing (A-302) or metal tubing connections (A-307). Includes hook-style variants with mounting flanges (A-302F).
• A-414 / A-417A / A-418 Series: Room-mount sensors featuring fine mesh screens or 60 micron filters for clean environments. These fit standard electrical boxes and include barbed brass fittings.
• A-306 / A-420 Series: Outdoor static pressure pickups designed to minimize wind effects. The A-306 is a complete kit with tubing, while the A-420A is a roof/outside mount unit with an EMT conduit fitting.
• A-489 / A-491 Series: Straight stainless steel static pressure tips for duct applications with mounting flanges in 4", 6", and 8" lengths.