There are many factors to consider when planning to machine flanges on-site. Operators and technicians often have to deal with safety concerns, time constraints, a variety of flange types, performance expectations and restrictive access to the flange. In the field today, technicians are using two types of flange facers to perform this work: ID-mounted or OD-mounted flange facers.
Looking for an expert perspective on common questions technicians face when using OD-mounted flange facers, BIC Magazine visited with CLIMAX Gulf Coast Area Sales Manager Tim Rhodus.
BIC: Why use an OD-mounted flange facer?
RHODUS: OD machines are mounted on the outside of the flange or pipe, making them the preferred option when there are obstructions, which make it more challenging to set an ID machine inside the bore. Most OD machines will cut to dead-zero center, something ID machines can’t do. OD-mounted flange facers are also perfect for heat exchangers, headers and covers, where ID machines cannot be mounted without any kind of custom-made tube sheet attachments.
BIC: What types of flanges can be machined with OD-mounted flange facers?
RHODUS: Most types of flanges can be machined using portable OD-mounted flange facing technology. However, many machines require additional assemblies to machine RTJs, hub profiles, lens rings and compact flanges. The exception is the CLIMAX and H&S TOOL ODFF machines, due to a unique slide-assembly design that comes standard. These machines are capable of machining every type of flange connection, including flat face, raised face, hub profile, lens ring, RTJ and compact flanges.
CLIMAX|H&S TOOL machines are easier to set up to machine RTJs because the slide assembly can adjust 360 degrees, and the tool holder can also independently rotate 360 degrees. This is unique, allowing users to position and machine any required angle.
BIC: What surface finishes can be achieved using OD-mounted flange facers?
RHODUS: The surface finish will depend on the type of cutting tool, rpm of the machine, depth of cut and feed rate you set. For example, setting the H&S TOOL OD30 Speed Facer at a feed rate of 0.008 inches per revolution (in/rev) with a 0.098-inch depth of cut will achieve a roughness of about Ra 63. Another example is if the OD70 Speed Facer is set at a feed rate of 0.003 in/rev with a 0.01- inch depth of cut, the achieved roughness will be about Ra 250.
BIC: What does hands-free machining mean?
RHODUS: Most flange facers on the market today are manually fed, requiring the operator to chase the feed device, inserting their hands into the rotating machine and manually rotating the feed. This is very dangerous, considering worker fatigue is the No. 1 cause of accidents in plants today. CLIMAX|H&S TOOL OD-mounted flange facers are equipped with an auto-feed system that keeps operators’ hands safe from moving and rotating parts while machining.
BIC: How are OD flange facers mounted?
RHODUS: The new lineup of H&S TOOL Speed Facers has a unique design to mount on the OD flanges with minimum setup time. It needs no welding, no special brackets and no fixtures. The technician simply measures the flange OD, positions the jacking legs to the right locations as guided in the manual, jacks up the legs to the OD of the flange, sets up a dial indicator to face-align and fine-adjust with the leveling jaw screws, and then sets the cutting tool. It takes only a few minutes to go from the box to the flange, hence the name Speed Facer. This feature plays a vital role in shutdown activities, where time is of importance.
For more information, visit www.cli maxportable.com or www.hstool.com.
