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  • Reliable Pipes & Tubes Ltd.
  • C-16, Anand Bhuvan, 163-165,
    V.P. Road, Mumbai - 400 004,
    Maharashtra, India.
  • Phone : +91 22 43431313 (25 Lines)
  • Fax : +91 22 23894511
  • Email : sales@reliablenickelalloys.com

Ferrule Tube Insert

Tube insert and ferrule are the same products, a metal, plastic or ceramic tube that is inserted into the end of a heat exchanger tube to provide a specific function. The purpose of a tube insert is to either be sacrificial to the effects of inlet-end erosion, corrosion, impingement to induce a fluid to fall on the ID of a tube in a falling film exchanger; or to transfer extremely high heat past the tube sheet to the exchanger tubes. Each of the above applications requires a specific style of design. We manufacture metal tube inserts for all applications, providing the necessary drawings required.
Even though there are some applications where plastic will perform satisfactorily, we have concerns of the stability of the product, its tendency to transfer erosion problems down the tube, its durability in an abrasive environment, and its reaction to elevated temperatures. A metal tube insert is more durable in these environments. In addition, ceramics perform well when the temperatures are extremely high, however they can be subject to breaking.

Tube Inserts For Falling Film Heat Exchangers
Here is where the design engineer can be creative. There are many designs and configurations for tube inserts in this application. The purpose of the tube insert is to induce a fluid to “fall” down the ID of the heat exchanger tube. The following, Figures 4 through 6, are representations of the various types of falling film inserts that have been produced over the years. We do not have any recommendations as to the benefits of one design over another.

falling film

High Temperature Applications

In applications where extremely elevated temperatures (1650 F) are present on the tube side of the exchanger care has to be taken not to warp the tube sheet. The use of tube inserts addresses this problem. Typically the tube insert has an hour glass form, creating an air gap between the tube insert and the parent tube. The gap is wrapped with high temperature (2300 F) ceramic paper. The paper is taped in place. We recommend taping the full length. There are two advantages for full length tape:

  1.  Higher temperature ceramic paper can be compressed on to the tube insert
  2. The tape protects the ceramic paper which cannot withstand even minor abuse.

The tube insert extends out of the tube and that space is filled with castable refractory. Some tube inserts have anchors that become imbedded into the refractory; others have pins with ceramic paper washers to set the tube insert at a specific height from the tube sheet. The ceramic washer inhibits heat transfer from the tube insert to the tube sheet. Figure 8 represents a typical design with high temperature paper. Figure 9 represents how a high temperature tube insert is positioned within a unit

The ferrule assembly consists of four components:


The ferrule is a metal tube insert formed to suit the application, and is completely wrapped with ceramic fiber paper of a suitable temperature rating, and completely taped. The taping is done under pressure, resulting in the compression of the ceramic fiber paper. A ceramic fiber washer is provided, sized to the application. The standoff tube is typically the same alloy as the ferrule and the same size as the heat exchanger tube. The components are assembled together as shown on the attached drawing.


There are a number of advantages to this system:

  • The ferrules can be removed, inspected, and if necessary, sent back to the factory for new ceramic fiber paper and taping, before returning to the unit.
  • Only the ferrules that are worn out need to be replaced. This can be accomplished without the removal of the refractory.
  • The design does not have any metal to metal contact from the ferrule to the tube sheet or the heat exchanger tube.

High Temperature

Figure 8



High Temperature


Reliable Pipes & Tubes Limited are certified for following :
Govt. Recognized Export House
OHSAS 18007:2007
ISO 9001:2008
ISO 14001:2004
PED Certified Company

quick contact

Reliable Pipes & Tubes Ltd.
C-16, Anand Bhuvan,
163-165, V.P.Road, Mumbai - 400004.
Maharashtra, India.
Phone : +91 22 4343 1313 (25 Lines)
Fax : +91 22 2389 4511
Email : sales@reliablenickelalloys.com