Portable Facing Services

"Teknokon Servis ve Bakım provides portable facing services for the industries with its experienced team and large machine capacities.”

Facing of flange surfaces is a machining maintenance service conducted on flange surfaces that have been damaged and worn due to process conditions and environmental conditions.

It is almost impossible to demount flanges to transport them to workshops for facing services due to the connection criteria or the criticality of flanges in systems. Under such circumstances, portable (field) facing services carried out with portable facing machines are integral part of industrial maintenance activities.

The two main criteria for portable (field) facing which are machine capacity and experience of the operator play a crucial role in the success of field facing services.
All portable facing (field facing) services provided by Teknokon Servis ve Bakım are performed by qualified personnel using portable machines with a high reliability level.

Maintenance of flange surfaces is usually among the activities planned during turnarounds. Therefore facing of flange surfaces is one of the critical activities performed during planned maintenance. Reliability and speed during this procedure is very important for our customers.

With the above in mind experts in Teknokon Servis ve Bakım perform a detailed work on the quality and time planning before conducting any maintenance activity.
Portable Facing Diameter Ranges
Flange surfaces with a diameter range of DN 25 (1 inch) - DN 1300 (52 inch) can be machined.
Examples and Areas of Field Facing
  • Raised face flanges
  • Ring type joints
  • O ring grooves
  • Exchanger Body Flanges, cylinder bundle front and back flange surfaces
  • Metal to Metal flange surface joints (high precision)
  • Manhole connections
  • Reactor Flange-Cap connections
  • Flange surfaces of equipment used in special processes

Causes of Flange Leakage:


Problems Caused by Tensioning and Torquing

Torque values lower than what is required for bolts and pins used as flange connecting elements can cause leakage due to loose fit whereas torque values higher than what is required can cause leakage due to the deterioration in gasket structure generated by these high values. Especially since high torque values used for metal alloy or spring type special gaskets in systems where high temperatures and pressure are found can cause permanent deformation of gasket surfaces, leakage will continue even required torque values are applied after using high torque values.

Problems Caused by Misalignment of Flanges

These problems include problems caused by flange installation. During the flange installation process, if alignment of flanges is not achieved, leakage continues even when correct gaskets are selected and correct torque values are applied. The solution is to remove and reinstall the flanges by aligning correctly.

Problems Caused by Improper Gaskets

Wrong gasket material or type or errors in centering of gaskets during installation can be examples of improper gasket use.

Problems Caused By Defects on Flange Surfaces  

Leakage on flanges caused by defects on flange surfaces is a significant part of the traditional maintenance activities. Damages/wear on flange surfaces can be caused by the following factors:

Foreign Objects and Dirt: This group includes damages on surfaces caused by foreign objects caught and trapped between flange surfaces during installation or maintenance.

Problems Caused by Friction: This group includes problems that especially occur in the joints that ensure metal to metal sealing resulting in deformation of surfaces over time.

Pits: This includes defects in materials and errors in manufacturing process as well as process conditions.

Damages Caused by Impacts: These include partial or overall damages caused by impacts inflicted on flange surfaces during installation or maintenance.

Problems Caused by Machining of Flange Surfaces: These include leakages caused by flange surface machining during factory processes or maintenance activities. Refacing of the flange surfaces by qualified personnel using suitable tools and equipment is necessary to correct the problem.  

Problems Caused by Thermal Stress

These include leakages on flanges due to temporary or permanent deformation of materials caused by changes in temperature. The source of thermal stress should be identified to eliminate such leakage problems. Thermal stress generally occurs due to process elements or environmental factors and cannot be eliminated easily.
Review of design criteria and improvements in design are necessary for process related factors whereas insulation or control of thermal conditions in the areas where systems are used are necessary to eliminate thermal changes caused by environmental factors.

Problems Caused by Too Much Vibration

High vibration in the systems where flanges are installed can cause loosening of flange connection elements over time leading to leakages. Leakages in this group can be permanently avoided only by removing the causes of vibration.

Errors in Design

These include errors in engineering and design processes or errors caused by non-conformance with design criteria during field applications. Errors falls into this group usually occur due to excess load on flange connections as a result of insufficient piping and equipment support systems. Design control and revision of the systems by qualified personnel are necessary to eliminate the errors in this group. Please note that excessive and unsuitable support systems as much as insufficient support systems can cause damage on industrial assets.