When expanding heat exchanger tubes, achieving the proper wall reduction is crucial for a secure and leak-free seal. Sometimes, however, tubes fail to expand sufficiently, hindering the integrity of the vessel. This article outlines common causes and troubleshooting steps for incomplete tube expansion.
Heat exchangers are critical components in nuclear, petrochemical, and energy production, often operating under high pressure and corrosive environments. These demanding conditions frequently necessitate the use of thicker tube sheets to ensure longevity and structural integrity. While thicker tube sheets offer enhanced durability, they present unique challenges during the tube expansion process.
Premature tube failure is a leading cause of downtime in heat exchangers operating in corrosive environments. Stress corrosion cracking is a common tube failure mode in corrosive environments, impacting any number of tubes in a vessel. While stress corrosion can be difficult to identify in the field, there may be ways to reduce the likelihood of occurrence.
Tube expanding is a technique used to create a secure connection between a tube and tube sheet, by compressing the outer diameter against a fixed surface. This process ensures a leak-proof joint that is crucial for the proper functioning of heat exchangers and other pressure vessels.
Plugging leaking tubes in heat exchangers is a critical maintenance task. However, this seemingly straightforward procedure can present a multitude of challenges that can impact both the success of the plug and the overall maintenance process. These challenges include creating a secure seal due to suboptimal tube conditions, limited reach and accessibility, and the availability of suitable plugging materials.
Tube removal is a common challenge regardless of the application. In air cooled exchangers, the layout of the tubes, as well as the outer diameter of the fins, could pose some challenges if using traditional methods. However, there are a few tips to make this process quicker.
Tube removal can be a daunting task, especially when encountering challenges like corrosion or tight spaces. One of the most frustrating situations operators face is the inability to pull a tube using a hydraulic puller. This article explores the four primary reasons behind this issue and offers simple solutions to overcome them.
The abundance of tube cleaning methods on the market can make it challenging to select the best option for a specific application. While factors like vessel type and deposit composition are crucial, it’s equally important to consider the limitations of each cleaning method.
Grooved tube sheets are the standard in most shell and tube heat exchanger applications. Providing both leak protection and improving the tube-to-tube sheet joints, grooves play an important role in prolonging the life of a tube and the efficiency of a vessel. However, in few applications where grooves are not required, there can be challenges during the tube expansion process.
Tube patterns describe how the tube holes are distributed through a tube sheet. Manipulating tube patterns helps increase flow but these modifications can create challenges for tube expansion.
