How To Clean Blocked Heat Exchanger Tubes

Tyson Klukan
May 30, 2025

Projectile Crews Unblocking Utube Heat Exchanger

Cleaning partially or completely blocked heat exchanger tubes can be a big challenge. So much of the success of the cleaning has to do with the makeup of the deposit and how it reacts to the cleaning process. Heat exchanger owners typically are unable to accurately supply deposit composition information until the unit has been opened. This situation makes estimating production rates for cleaning very difficult.

It is usually common in situations like this for contractors to underestimate the actual cleaning time. It is best for both parties to understand that with cleaning blocked heat exchanger tubes that the unknown variables are higher than a standard cleaning job and this could lead to extended job times and cost overruns.

Two Types of Drills Used for Unclogging Tubes

Flexible Shafts:

Flexible shafts are easier to use and ideal for confined spaces like condensers because the shafting can bend into tight spaces. The downside of using a flexible shaft drill in unclogging a blocked heat exchanger is that it does not create as much torque and thus is not as effective at removing deposits. The flexible shaft is also much slower at removing tube deposits.

Solid Shafts:

The solid shaft creates much more torque and can eat through tube deposits much faster. The drawback of using a solid shaft is that it makes drilling much more difficult and laborious. If the heat exchanger is 30 feet long, you need to assemble 30 feet of shafting and push the drill in and out of the tube the entire length. If there is not enough clearance for the shafting, then the operators need to assemble the shafting sections as they drill.

Projectile crews using a solid shaft to clean vertical heat exchanger

Drill Tips For Unclogging A Block Heat Exchanger

Drill tips are an important component of the cleaning process. They are designed especially for heat exchanger tubing. As noted above, the drill tip is designed to be smaller than the tube so it does not touch the tube wall. There are different drill designs depending on the consistency of the deposit. One would use a different drill tip for hard calcium deposits than they would for gummy oil-based deposits, for example. Contact us as Projectile sells drills, extensions and drill tips for any heat exchanger cleaning projects.

The last step in this process is shooting Metal Projectiles through the tubes. This last step will successfully remove the remaining deposit attached to the wall of the tubing that the drill bit left behind.

Projectile Tube Cleaners

Metal Projectiles

The method that Projectile uses for cleaning blocked and partially blocked heat exchanger tubes is a two-part method. First, the tubes are drilled with specialized heat exchanger drilling equipment. After the drilling is done, Metal Projectiles are used to remove the remaining scale from the tubes.

The reason the cleaning is done in two steps is that the drilling equipment is designed not to touch the tube wall. The specialized tube drill bit is sized about 0.010-0.030 inches under the inner diameter of the tube. Thus after the drilling, some deposit will still remain on the tube. The Metal Projectiles are then shot through the tubes with a low-pressure pumping system to scrape off the remaining deposits from the tube wall.