Tongue and Groove Flanges — ASME B16.5 & EN 1092-1

What are Tongue and Groove Flange?

In a tongue and groove joint, the gasket sits in the bottom of the groove and is enclosed by the tongue, so it cannot blow out and stays centred during assembly. Because the faces interlock, the two flanges must be ordered as a matched pair, and the line must be designed so a flange can be moved axially for dismantling. T&G faces are used in pump covers, valve bonnets, and services where the gasket must be confined, such as hazardous or high-pressure fluids with soft gaskets.

Key features

• Gasket fully confined; cannot blow out
• Self-centring during assembly
• Large and small T&G facings per ASME B16.5
• EN 1092-1 Type C (tongue) and Type D (groove)
• Supplied as matched pairs

Specification

Applications

• Pump casings and covers
• Valve bonnets and bodies
• Heat exchanger channel covers
• Hazardous chemical lines with confined gaskets

Tongue and groove vs male and female

Both are interlocking matched-pair facings. In a male and female joint the gasket sits on the female face and is confined on its outside diameter only. In a tongue and groove joint the gasket sits in the groove and is confined on both inside and outside diameters, so it is better protected from erosion and blow-out but needs more precise machining.