Our experience as a manufacturer of heat exchangers and evaporation systems provides us with the insight of common heat exchanger failures. This knowledge of heat exchanger design and operation is critical when making repairs, as a small repair on a heat exchanger done improperly can result in a major failure later on.
We are familiar with repairing most types of heat exchangers. All repairs are non-destructive tested (NDT) to verify integrity of repairs. Our field technicians are rigidly trained in the latest heat exchanger standards and are certified in most common pressure vessel codes.
Understanding Failure Types
Failures as Result of Operational Fatigue
The operational strain on a heat exchanger can be extremely demanding. The fluctuations of thermal and pressure conditions on a heat exchanger will result in cyclic stresses due to expansion and contraction. If not considered in the design and during construction, the cyclic stress can produce extreme stresses on the heat exchanger resulting in premature failures.
Most heat exchanger manufacturers will include some type of expansion and contraction absorbing devices, such as expansion joints. Any repairs made on this type of equipment must be done with these stresses being considered.
Failures as Result of Corrosion
Corrosion failures are very common in heat exchangers, as the elevated temperatures during operation can intensify the attack of many elements. The rate of corrosion can vary greatly based on the metallurgy selected for a specific application, and the operating conditions that the material is exposed. Typical selection of a material for an industrial application should be done for a minimum of 20-30 year life expectancy, but in many circumstances a less suitable material is selected due to expense.
Intelligent equipment design and fabrication can aid in the longevity of a product against corrosion, by ensuring proper flooding of wetted parts or proper treatment of based metals through the manufacturing and welding processes. Corrosion repairs are more difficult to complete, as it will typically require welding in the area of active corrosion. Although, if done properly, the repairs can be an acceptable solution in short term, until a replacement unit can be considered.
Failures as Result of Erosion
Erosion failures are typically an effect of inadequate system design or improper operation. Generally, they are caused by exceedingly high liquid or gas circulation velocities in process piping, elbows, transitions, and distribution systems. Once a failure is identified, the repair will generally include some redesign to remedy the problem long term.