RTJ Flange Repair – On-Site Ring Type Joint Flange Machining

RTJ Flange Repair – On-Site Ring Type Joint Flange Machining

RTJ flanges (Ring Type Joint) are widely used in high-pressure and high-temperature piping systems, making them a standard choice for API specification flanges. Typical applications include oilfield valves, pipeline systems, pressure vessels, and other critical industrial joints where leak-free performance is essential.

Unlike flat face (FF) or raised face (RF) flanges, RTJ flanges use a metal ring gasket seated in a precisely machined groove to form a metal-to-metal seal.

Key Characteristics of RTJ Flanges

• Use solid metal ring gaskets instead of soft composite gaskets
• Feature a precision-machined groove to locate the gasket
• Create a metal-to-metal seal when compressed
• Softer gasket material flows into the harder flange surface for sealing
• Designed to resist over-tightening, vibration, and movement

These features make RTJ flanges ideal for demanding operating conditions.

On-Site RTJ Flange Groove Machining

RTJ groove dimensions must comply with ASME B16.5 standards. This work can be performed on-site using portable flange facing machines, eliminating the need for flange removal and reducing downtime.

MT Portable Machines flange facers are designed to machine RTJ grooves without additional optional attachments, ensuring efficient and accurate on-site repair.

RTJ Machining Capabilities

Portable flange facing machines typically use one of two axial feed systems to create the required 23° sealing faces:

Automatic axial feed

Ideal for precision RTJ machining and long-duration work.

Typical models: FI40, FI60, FI80

Striker (kick-feed) axial feed

Axial movement is controlled by a striker mechanism or manually by the operator.

Typical models: FE12, FI26

Both systems also support manual feed for fine adjustments.