Flange Facing Machine FAQS

Manufacturers of all kinds of industrial products go to great lengths when promoting the features and benefits of their products on their websites. But many don’t offer any real guidance on how to choose the right machine for each individual customer’s needs. To help you, we are happy to provide a guide to people who want to know more about flange flanging products. Included are answers to some of the most common questions our technical sales team encounters.

We have divided the article into ‘Basics for Beginners’, ‘Applications’, ‘Selecting a Flange Facing Machine’ and ‘How to Operate a Flange Facing Machine’.


If you are new to flange facing. Here are answers to some of the more basic questions;

Why do you need flange facing machines?

Although flanges with machined surfaces are mass-produced, damage to the flange surface may occur during shipping and installation. This causes scratches and dents on the sealing surface. Damage like this compromises the integrity of the joint – with potentially catastrophic results. Even after pipelines are commissioned, the integrity of a joint can be compromised by corrosion within the joint. In this case, the flange will need frequent replacement and can be removed with a splitting frame/clamshell cutter.

What Are The Main Industries Using Flange Facing Machines?

This includes petrochemical and pharmaceutical production plants, oil wells, pipelines and power plants.

How do flange facers work?

They work much like a gramophone player, with the cutting tool spiraling across the face of the flange. This finish is commonly specified for flanges in the oil and gas industry, where the gasket material is compressed to fill the helical groove. A flange with a spiral grooved surface is less prone to leaking because the gas or liquid is forced to travel the long spiral path rather than across the flange face.

How are they powered?

Pneumatic is the standard method but hydraulic versions can be provided as an option on many machines in the range.

How do I know if the flange surface needs to be machined?

We encourage you to read our previous blog article which has a section on what ASME states as acceptable flange damage .


Raised Face Flanges, Heat Exchanger Flanges, Techlok Flanges, Recessed Gaskets and Journals, Weld Prep, Hub Splines, RTJ Flanges, Lens Ring Joints, SPO Compact Flanges, Rotating Ring Flanges.

Note: To run some of the above applications, you need additional options and accessories.

What options and accessories are available?

Optional components to expand the capabilities of the flange facing machine include:

  • Compact flange processing kit for upgrading your existing flange processing machine. Alternatively , you can specify a special compact flange facing machine when ordering.
  • Pivot/shaft turning set
  • Mounting kit heat exchanger
  • Heat Exchanger Back Cover Kit
  • Lens Ring Machining Kit
  • Orbital Milling Kit, replaces the single point tool holder with a milling head.
  • Hydraulic conversion kit – for converting a pneumatic machine to a hydraulic drive .

Can a flange facing machine work in an underwater environment?

Yes, but it must be powered by hydraulic.


What machine size do I need?

There are many flange preparation machines available in different sizes, for example the smaller machines can be used for flanges from 2″ to 12″ and the larger machines cover sizes from 45″ to 120″. Additionally, the MM1080ie is a unique design that can be internally or externally mounted and used to machine flanges from 0″ to 157″ in diameter.

Should I choose a hydraulically or pneumatically driven flange milling machine?

This depends on the availability of an airline at your project location. Pneumatic machines are the most common type of flange planer, but hydraulic versions can be used with a power pack in locations where pneumatic is not an option. The good news is that it is often possible to convert a pneumatic machine to hydraulic with a conversion kit.

Do I need an ID or OD mounted flange facing machine?

This depends on being able to access the hole in the flange to install the mounting legs. ID mount machines are the most common type, but OD mount versions are often used where access to the flange bore is restricted.

What are the most common problems with cheap flange prep machines?

Of course, price plays an important role when choosing your priorities, but buying only by price is false frugality, as unfortunately many cheap flange prep machines are not robust enough and just aren’t up to the task. If a machine is not stable, it can move during the machining process, damaging the flange and creating an uneven surface finish. Another problem is that some machines don’t have preset gears. These cheaper variable feed machines can (theoretically) produce a wider range of finishes, but can be inconsistent and cumbersome to operate. By choosing a machine with preset feed rates, you’ll achieve consistent helical groove finishes every time.


How can I create a spiral gear?

Surface finishes are created with fixed gear feeds to help meet ASME B16.5 specifications.

In what positions can they be mounted?

Flange facing machines can be mounted at any angle, including inverted orientation. If the assembly is not horizontal, the alignment arm is balanced using adjustable counterweights.

How to set up a flange facing machine

For Internal Assembly Flange Machining Tools; The base unit is pre-assembled and presented to the flange by means of adjustment tabs that rest on the edge of the flange face. The base legs are then adjusted to clamp in the bore and the machine is secured to the base unit. The position of the machine is finely adjusted and controlled using a watch clock. When they are level, the straps are removed and machining can begin.

How long does it take to machine a flange face?

The actual processing time is usually only a few minutes. Most of the time that is spent on a flange facing is taken up with the assembly and disassembly of the machine.

What maintenance is required?

With proper care, the flange facing machine will provide years of trouble free service , producing accurate and consistent results every time. Simple cleaning, removing dirt and oils is usually all that is needed.