Why Do Flanges Leak, And How To Fix Them?

Flanges are the products suitable in heat exchangers as an integral portion and also in a processing operation. Several things that affect the operational capacity of the flanges includes high-pressure equipment and such as leakages. Leakage is not acceptable in process equipment. Based on the heat exchanger, its applications and usability depend, and they decrease productivity as well. Further, various procedures contaminate heat transfer fluid, creates issues of environmental safety and hazards. Also, leakage in flanges leads to life-threatening issues such as a fire. Hence, it is essential to identify the leakage in flanges immediately after its detection.

What are flanges?

Flanges have several components, such as a ring, a gasket, and bolts. Here, bolts are there to hold the flange in one plane and support the exchanger. After leakage of flanges, it is essential to identify their location and determine the cause.

Following are several possible causes of flange leaks:

  • Unequal bolt stress
    Improper bolting process or cramped working environments surrounding the flange makes some bolts lose. Unequal bolt stress tightens and crushes the gasket. These stress conditions create leakages, especially in high temperatures and after the relaxation of heavily loaded bolts.
  • Improper alignments of the flange
    Improper flange alignment develops unequal gasket compression, local crushing and causes subsequent leakage. Unequal flange centreline alignment also brings unequal gasket compression and results in flange leakages.
  • Improper gasket centering
    When a gasket installation is off-centered to the flange faces, it causes uneven gasket compression. Also, it makes the joint prone to further leakage. Double jacket and spiral wound gaskets have a centering ring that extends to the bolts’ inner edge. Gaskets cut properly so that its exterior diameter meets the inner edge of the bolts.
  • Dirt and damage to flange faces
    Various damages to flanges in the form of dirt, scaling, internal and external scratches, protrusions, and weld spatters. Also, the flanges with warped seating surfaces increase the chances of leakage, and it can cause uneven gasket compression and ultimately result in flange leakage.
  • The additional load on flanges
    A huge piping network creates load at flange locations. Such forces and bending events can loosen the bolting portions. Such distortions of the flanges can lead to leakages.
  • Temperature shock
    Random changes in thermal energy fluctuations can cause deformation in flanges for a limited time. The varied temperature around the flange causes problems with to flange location. Sheet metal shields are essential to protect against rain and snow impingement. These conditions develop gradients of heat throughout the flange and lead to leakage. Metal shields protect the flanges at a uniform temperature.
  • Unsuited flange surface
    If the flange has deeper serrations compared to specified prevents the arrangement of double jacketed or spiral wound gaskets, it creates space for leakage.
  • Benefits of immediate leak identification
    Several leakage detection and repair methods are available, and it helps in saving the entire piping system. With proper flange leakage detection, petroleum refineries can control the emissions from leaked portions. Further, it improves plant workers’ safety level, reduces emission costs, and supports the environment.

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Why Do Flanges Leak, And How To Fix Them?

by Piping Mart time to read: 2 min