Gulf E&C
Contact Us
News & Insights
ABOUT US

Delivering Quality, Committed to Safety, Caring for People, Strengthening Communities

What Is HeatExchanger Retubing?
  • Definition: Retubing is the process of removing old, corroded, damaged, or inefficient tubes from a shell-and-tube heat exchanger and replacing them with new ones.
  • Purpose: The goal is to restore thermal efficiency, prevent leaks, and extend the life of the heat exchanger without replacing the entire unit.

Cost-Effectiveness: Retubing is often much less expensive than a full exchanger replacement.

When Is Retubing Needed?

Retubing is generally considered when:

  • Tubes are leaking (corrosion, pitting, cracking).
  • There is heavy fouling, scaling, or blockages.
  • Tube wall thinning is detected (e.g., via non-destructive testing).
  • A significant number of tubes are compromised and tube-plugging is no longer sufficient.
Retubing Process (Step-by-Step)
  1. Inspection & Diagnosis
    • Use borescopic inspection, eddy current testing (ECT), ultrasonic thickness gauging, etc. to assess tube condition.
  2. Tube Removal
    • Remove the old tubes by cutting or pulling them out. 
    • If tubes are welded to the tube-sheet, break welds first.
  3. Tube Sheet Preparation
    • Clean the tube-sheet holes, prepare them for the new tubes.
  4. New Tube Installation
    • Insert new tubes, of matching material, thickness, and length. 
    • Expand (roll) the tubes or weld them to the tube sheet to seal.
  5. Welding & Seal
    • If needed, weld tube-to-tube sheet joint for a tight seal.
  6. Testing
    • Conduct a hydrostatic (pressure) test to ensure no leaks.
  7. Post-Retubing Inspection
    • NDT (non-destructive testing) like ECT or ultrasonic to check weld quality and tube integrity.
Types of Retubing
  • Full Retubing: All tubes are replaced.
  • Partial Retubing: Only damaged tubes are replaced.
  • Plugging + Retubing: Some tubes are plugged (if irreparable) + others are retubed.

Tube-Sheet Reconditioning: Sometimes the tube sheet is resurfaced or replaced before inserting new tubes.

  • Tubes can be of copper, brass, stainless steel, nickel alloys, titanium, etc., depending on application.
  • Tools: Specialized tube pulling tools, expanders, welding equipment.
  • Inspection and testing tools: ECT probes, IRIS, phased-array UT, etc.
Materials & Tools
Advantages of Retubing
  • Restores thermal efficiency of the exchanger.
  • Extends equipment life without needing full replacement.
  • Reduces downtime compared to installing a completely new heat exchanger

Can upgrade tube materials (e.g., to more corrosion-resistant ones).

  • If too many tubes are damaged (or other parts like baffles are bad), retubing may not be economical.
  • Quality of tube-to-sheet welds is critical; bad welds = leaks.
  • Retubing requires specialized tools and skilled labor.
  • After retubing, if inspection is not done well, degraded tubes may remain.
Risks / Challenges
Key Companies / Service Providers
  • RetubeCo: Specializes in condenser and heat exchanger retubing.
  • Lanbo Group: Provides on-site retubing services, has done hundreds of projects.
  • AVN Technologies: Offers retubing, NDT (ECT, IRIS), welding, inspection.
  • Kanooz: Retubing & refurbishment services (on/off-site) for various heat exchangers.
  • Framatome: Life-extension retubing (partial or full) with improved materials in power plants. 

GTT OnSET: Provides tools + installation/removal services for retubing.

Standards / Guidelines
  • TEMA (Tubular Exchanger Manufacturers Association) provides design and construction standards for shell-and-tube heat exchangers.
  • Use of NDT and inspection methods is critical for assessing when retubing is needed.
  • ASME / NBIC standards may apply depending on the type of heat exchanger and service conditions.
Alternative to Retubing: Sleeving
  • Tube Sleeves: Instead of full retubing, a sleeve can be inserted inside the degraded tube to repair it.
  • Sleeves are available in different materials (stainless steel, nickel alloys, copper, etc.) and sizes.
  • This is useful when most of the tube is fine but only certain parts (e.g., near the tube sheet) are eroded.
Case Studies and Use-Cases
  • In power plants, retubing is used for feedwater heaters, condensers, and CCW (closed cooling water) heat exchangers.
  • In petrochemical / refinery plants, fouling and corrosion lead to tube damage, making retubing critical.
  • For older heat exchanger units, retubing can be a way to avoid full replacement and save cost/time.
  • As plants age, tube wall thinning becomes more common, necessitating retubing.
  • Material choice is important: upgrading to more corrosion-resistant materials during retubing can improve longevity.
  • There’s increasing use of NDT technologies (IRIS, eddy current) for precise diagnosis.
  • Retubing during tight turnarounds / outages is common in power plants, so efficiency and tooling matter.
Challenges in Industry (Trends)