Flange Facing Machines

In-service flanges fail by face corrosion, gasket impingement, or RTJ groove wash. Removing the flange to a shop is rarely viable on a live pipeline — the line above it would have to come down too. The fix is an in-situ portable flange facer that mounts on the flange ID, resurfaces the face and re-cuts the groove in one setup.

For RTJ groove restoration the rules are non-negotiable: 23° walls within 0.5°, Ra ≤ 1.6 µm in the groove, concentric to the bore. For the full field procedure see how to machine RTJ grooves.

The flange face is not cosmetic — it is the sealing parameter. A smooth finish on a soft sheet gasket leaks; a stock finish under a smooth-face gasket leaks. Each combination has a finish band per ASME B16.5 / B16.20.

A portable flange facer controls the face finish through feed rate and insert geometry — Ra 6.3 µm for stock, Ra 1.6 µm for smooth, controlled spiral pitch for serrated. For the full gasket-to-finish matrix see flange surface finish explained.

During a TAR or offshore shutdown, every flange repair competes for hot-work permit time. Cold machining is permit-free, which on a live unit translates directly into more productive hours per shift — and sometimes the difference between hitting the start-up window and slipping it.

For the broader pneumatic-vs-electric drive decision in hazardous zones, see pneumatic machining in oil & gas safety. Bring the flange OD, groove type and area classification to the quote form and we will match a machine sized for the window you have to work in.