Description

Overview

The ST-4 Air Brake Safety Valve 3/8 protects trailer air reservoirs by venting excess pressure before damage occurs. It suits heavy vehicle air systems that use a single-port, flush-mounted valve on the tank, providing simple installation and reliable protection for fleets and workshops.

Features of the ST-4 Safety Valve

• 3/8 inch pipe thread for direct reservoir mounting
• Factory set to 150 PSI to suit common trailer air systems
• Single-port ST-4 style body for straightforward plumbing
• Flush-mount design that resists snagging and reduces leak points

Specifications and Materials

Part number: AB830A.

For responsibilities and guidance on air receiver relief valves and set pressure, see this Safe Work Australia information sheet.

Compatibility and Fitment

Always confirm the thread type on the tank, the set pressure required by the system, and available clearance for flush mounting. This cross-reference listing means this valve is a suitable replacement for the part numbers and applications shown. Some changes in air line plumbing may be required.
Bendix 284143.

Compliance and Safety for the ST-4 Safety Valve

Select a set pressure that does not exceed the air receiver design pressure. Install and test the valve using competent workshop practices. Do not tamper with the factory seal. Inspect the receiver and test the release mechanism at service intervals, because periodic checks help verify safe operation.

Trailer Applications

Use this valve on general freight, tipper, tanker and container trailers that specify an ST-4 style relief device. It is suitable for air reservoirs on Australian heavy vehicles where a 150 PSI setting is common. Because it is a compact unit, it also works well as a service replacement during tank changeovers or brake system overhauls.

Cross-reference and Suitability

This part cross-references to or suits the following equivalent part numbers and compatible alternatives:

Why Choose ICS Trailers

ICS Trailers sources proven air brake components and publishes clear, selection-critical specs so you can order with confidence. Our team understands heavy trailer systems and supports fleet, repairer and owner-driver needs from one place. Browse Air Brake Parts at ICS Trailers