19 Series AIR-FUSE Flow Diffusers – Installation Instructions

Overview

The ROSS Controls® 19 Series AIR-FUSE Flow Diffusers are spring-operated safety devices designed to protect personnel and equipment from the hazards of compressed air hose failure. Installed in-line between fixed pipe work and a flexible hose, the AIR-FUSE automatically closes when a downstream hose bursts or a tool uncouples, preventing dangerous hose whipping and uncontrolled air discharge. The device is designed to protect flexible hose users from the severe injury risk posed by whipping high-pressure hoses.

The AIR-FUSE operates on a pressure-differential principle. During normal operation, air pressure upstream and downstream of the fuse is approximately equal and the spring holds the valve open. When a downstream hose ruptures, the resulting sudden surge in air flow overcomes the spring force and the valve closes. The valve remains closed until downstream and upstream pressures equalize through a small bleed hole, at which point the spring reopens the valve and full flow is restored.

ROSS Controls has manufactured pneumatic safety products since 1921. The 19 Series AIR-FUSE is part of a legacy product line. Contact ROSS at 1-800-GET-ROSS or visit www.rosscontrols.com for current product availability.

Key Features

Automatic Hose Whip Protection

The AIR-FUSE is a normally open, spring-operated inline valve. Under normal flow conditions the device presents negligible restriction. When a downstream hose bursts or a tool uncouples causing a sudden flow surge, the AIR-FUSE closes automatically, stopping uncontrolled air discharge and preventing hose whipping. No manual intervention is required for initial protection.

Automatic Reset After Fault Correction

Unlike permanent-closure safety devices, the AIR-FUSE resets automatically when the downstream fault is corrected. The bleed hole allows a small quantity of air to pass in the closed state, gradually rebuilding downstream pressure. When pressure equalizes, the spring opens the valve and normal flow resumes, minimizing production downtime after a hose fault.

Port Size Range with Scaled Shut-Off Flow Data

The 19 Series AIR-FUSE is available in female-female porting for port sizes from 1/4 inch through 1-1/2 inch. Shut-off flow rates are scaled to match protected hose and tool requirements at 100 psi (7 bar) inlet pressure, enabling proper sizing for each application.

Technical Specifications

The following specifications are drawn from the official ROSS Controls 19 Series AIR-FUSE Installation Instructions (Doc ID 100):

Ambient/Media Temperature: 35° to 175°F (2° to 80°C); consult ROSS below 35°F (2°C)
Flow Media: Filtered air
Operating Pressure Range: 0 to 300 psig (0 to 20.7 bar) maximum
Mounting: In-line two-way valve between fixed air supply and flexible air lines
Housing Material: Aluminum
Inner Parts Material: Brass
Spring Material: Stainless Steel
Porting Type: Female-Female (all sizes)
1/4" Port: Shut-off flow 29.7 scfm (14 dm3/s); Flow at ΔP 1 psi = 13.8 scfm (8 dm3/s) at 100 psi
3/8" Port: Shut-off flow 68.2 scfm (32 dm3/s); Flow at ΔP 1 psi = 28.6 scfm (14 dm3/s) at 100 psi
1/2" Port: Shut-off flow 102.3 scfm (48 dm3/s); Flow at ΔP 1 psi = 49.2 scfm (23 dm3/s) at 100 psi
3/4" Port: Shut-off flow 169.5 scfm (80 dm3/s); Flow at ΔP 1 psi = 91.1 scfm (43 dm3/s) at 100 psi
1" Port: Shut-off flow 271.0 scfm (128 dm3/s); Flow at ΔP 1 psi = 144 scfm (68 dm3/s) at 100 psi
1-1/2" Port: Shut-off flow 568.0 scfm (268 dm3/s); Flow at ΔP 1 psi = 307 scfm (145 dm3/s) at 100 psi

Applications

Compressed Air Tool and Hose Protection

The AIR-FUSE is installed in compressed air systems between fixed pipe work and flexible hoses. Typical applications include pneumatic tools (grinders, drills, impact wrenches), spray gun applications, and any industrial application where flexible compressed air hoses connect to fixed supply lines. The AIR-FUSE is particularly important in applications subject to OSHA 29 CFR 1926.302 requirements for hose protection.

General Industrial Compressed Air Distribution

The AIR-FUSE is used in a variety of compressed air system applications where flexible hose integrity is critical. All safety precautions for compressed air systems must be observed: never exceed pressure ratings of any component, protect material and air lines from damage, never point spray guns at persons, check hoses before each use, and release all pressures before servicing.

Safety and Compliance Standards

Before servicing any pneumatic component, all energy sources must be turned off, the pneumatic system shut off and exhausted, and all power sources locked out per OSHA 1910.147 and EN 1037. Do not exceed the pressure rating of any component in the system (maximum 300 psig for the AIR-FUSE). Use metal bowl guards on ROSS filter and lubricator bowls where provided.

Installation and Setup Guide

Installation Procedure

Shut off air pressure before installing the AIR-FUSE. Install in the air line between fixed pipe work and flexible hose with air flow in the direction of the arrow marked on the body. Connect piping using pipe thread sealant on male threads only – do not allow sealant to enter the interior of the unit. After installation, confirm that the AIR-FUSE functions properly by performing the check procedure.

Operation – Checking the AIR-FUSE

Connect tool to air hose, then slowly apply air pressure (rapid pressurization will trip the AIR-FUSE). Operate the tool several times. Shut off air pressure and reduce pressure to zero. Disconnect tool from hose and properly secure the hose end. Slowly apply air pressure – the AIR-FUSE should activate and cut off flow after the rated shut-off flow is reached. If it does not activate, replace with a lower flow model.

AIR-FUSE Size Selection

Select the AIR-FUSE model based on the maximum flow rate of the tool or equipment being protected. The shut-off flow rate must be higher than normal tool operating flow but reachable by the supply system when the hose is disconnected. If the air supply cannot deliver the required shut-off flow rate (e.g., miniature low-flow products), the AIR-FUSE may not protect the downstream hose.

Why Choose ROSS Controls

ROSS Controls has over 100 years of experience designing safety solutions for compressed air and fluid power systems. The 19 Series AIR-FUSE reflects ROSS's commitment to worker safety through simple, reliable automatic protection. For current product availability, contact ROSS at 1-800-GET-ROSS or visit www.rosscontrols.com.

Download This Document

The official ROSS Controls 19 Series AIR-FUSE Flow Diffusers Installation Instructions (Doc ID 100) can be downloaded from the ROSS Controls document library.

PDF Download URL: https://ross-admin-global-us-east.s3.amazonaws.com/production/uploads/document_language_file/file/100/ROSS_19_Series_Air-Fuse_Flow_Diffusers_SS310.pdf

Frequently Asked Questions

Q: How does the AIR-FUSE close when a hose bursts?

A: When a hose bursts, the sudden surge in air flow downstream overcomes the spring force holding the AIR-FUSE open. The differential pressure forces the valve closed, blocking further air flow and preventing hose whipping.

Q: Does the AIR-FUSE reset automatically after a hose burst?

A: Yes. A small bleed hole in the AIR-FUSE allows air to seep through after closure. When the burst hose is repaired and the downstream side is sealed, the bleed air builds up downstream pressure until it equals upstream pressure, at which point the spring reopens the valve.

Q: What is the maximum pressure rating of the AIR-FUSE?

A: The 19 Series AIR-FUSE has a maximum operating pressure of 300 psig (20.7 bar). Do not exceed this rating in any installation.

Q: What is the temperature range for the AIR-FUSE?

A: The ambient/media temperature range is 35° to 175°F (2° to 80°C). For temperatures below 35°F (2°C), consult ROSS Controls.

Q: How do I select the right AIR-FUSE size?

A: Select based on port size to match the hose and pipe work, and verify the shut-off flow rate is appropriate for the tool being protected. The shut-off flow rate must be higher than the normal tool operating flow but reachable by the supply when the hose is open. Port sizes range from 1/4" to 1-1/2", all female-female porting.

Q: Why might an AIR-FUSE trip on initial pressure application?

A: Rapid pressurization will trip the AIR-FUSE because the initial pressure surge exceeds the spring force. Always apply air pressure slowly after installation or after connecting a tool.

Q: What materials are used in the AIR-FUSE?

A: The housing is aluminum, inner parts are brass, and the spring is stainless steel. All materials are compatible with filtered compressed air service within the specified pressure and temperature limits.

Q: Is the 19 Series AIR-FUSE a current product?

A: The 19 Series AIR-FUSE is part of a legacy ROSS Controls product line. Contact ROSS Controls at 1-800-GET-ROSS or visit www.rosscontrols.com for information on current availability.