Description

Overview

The TR-3 inversion valve 42 52 psi manages inversion of air pressure signals in heavy vehicle air brake systems so a protected circuit takes over when control pressure falls. It suits trailers, dollies and truck applications that use TR-3 style circuits to switch from service to emergency reservoirs. As a result, it helps maintain controlled brake response if a control circuit loses pressure. In addition, the compact body and standard porting make retrofit work straightforward for fleet workshops.

Features

• TR-3 pattern inversion valve that transfers supply from a protected reservoir when control pressure drops
• Pressure range 42 to 52psi to suit common lift axle and parking brake control layouts
• 1/4″ NPT supply and delivery ports for easy plumbing with standard air brake fittings
• Robust die cast style body suited to heavy road transport and fleet duty cycles

Specifications and Materials

This TR-3 inversion valve 42 52 psi configuration uses a normally open, pilot-operated layout so the delivery port exhausts under normal conditions and applies protected reservoir pressure when control pressure falls. The valve body provides 1/4″ NPT supply and delivery connections, plus an inversion control interface that ties into the trailer or dolly brake circuit. It is intended for use in compressed air brake systems that meet heavy vehicle standards and should only be installed by trained technicians. Part number: AB8356P.
For detailed operation, mounting and service information on TR-3 style valves, refer to the manufacturer technical guide for TR-3 inversion valves

Compatibility and Fitment

This valve suits heavy trailers, converter dollies and truck applications where an inversion valve supplies air to spring brake or lift axle circuits from a protected reservoir. It is typically mounted close to the protected reservoir and associated relay valves so line runs stay short and response remains consistent. 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. 289288.

Compliance and Safety

You must always drain the air system fully and isolate the vehicle before removing or installing an inversion valve, otherwise stored air can move components unexpectedly. Follow the vehicle builder and valve technical documentation for torque values, port allocation and mounting orientation. Additionally, perform leak checks and functional tests after installation so the TR-3 inversion valve 42 52 psi operates as intended within the overall brake system.

Trailer Applications

Workshops fit this TR-3 inversion valve 42 52 psi pattern on trailers and dollies that use protected reservoir circuits for parking brakes or lift axles. In many layouts it works with relay valves, spring brake chambers and control valves to give controlled application when a fault occurs. Consequently, fleet operators gain more predictable behaviour during line failures and improve protection for tyres, suspensions and freight.

Cross-reference and Suitability

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

Use this table to confirm interchange with existing catalogue numbers when you are replacing an older TR-3 style inversion valve in fleet service.

Why Choose ICS Trailers

ICS Trailers focuses on proven heavy vehicle air brake parts, so you can match TR-3 style inversion valves confidently across trailers and dollies. The team understands fleet downtime pressures and helps you pair valves, fittings and brake hardware for clean, reliable installations. Browse more Air Brake Parts at ICS Trailers today