Reference · diagnosis · service
Identify the cause of failure first. Then consider cleaning, restoring leak tightness, replacing parts or replacing the exchanger.
Photographs and a description help identify the construction and plan the inspection. The cause of a leak, metal condition and repairability require inspection and appropriate tests.
Record the symptom and when it appeared. A qualified technician must safely isolate the exchanger before disassembly.
Follow the evidence, one step at a time
What changed, and under which conditions?
Which construction and which circuit?
What inspection can establish the cause?
Compare temperatures, flows, pressure drop and filter condition. The exchanger itself is not always the cause.
Check material condition, access, spare parts and the consequences of another failure. Prepare information for both options.
Choose the construction. Each family below shows typical issues, possible work and decision limits.
An openable pack gives access to individual components.
Gaskets separate the channels between plates; the plate pack can be opened for inspection.
Brazed plates form a closed pack.
Plates are brazed together; routine disassembly and regasketing are not available.
Which side of the separating surface is affected?
One fluid flows through tubes and the other through the shell. The construction determines access to the bundle.
Look at the air path as well as the fluid path.
Tubes and fins form an air-side coil: a heater, air cooler, evaporator or condenser.
Several channels share a flat tube connected to headers.
Flat multiport tubes connect to headers; the construction is often aluminium.
Identify the construction before borrowing a method.
Welded and semi-welded plate, spiral, coil-wound, plate-fin exchangers and heat-recovery units.
A symptom is an observed change. A cause is a defect or condition that still needs verification. Keep them distinct.
“It heats less” describes a symptom, not its cause
Record the changed temperatures and the operating situation.
Check available flow and pressure readings against a comparable earlier condition.
This example organizes the inspection; it does not diagnose fouling or damage.
Gaskets, tubes, headers or joints may be damaged; distinguish condensation from a leak.
For assessment: Photograph the unit and the affected area. Record fluid, pressure, temperature and when the leak appears.
Check fouling, flow, trapped air, filters and controls. One temperature reading is not sufficient.
For assessment: Record both fluids’ inlet/outlet temperatures, flows or available measurements, and cleaning history.
Blockage, deposits or a changed flow may be responsible. Compare equivalent operating conditions.
For assessment: Provide pressure drop, pump/fan operating conditions, connection arrangement and filter condition.
Surface icing and structural damage after freezing are different cases. Assess flow, fluid and protective controls.
For assessment: Provide photographs, the sequence of events, temperatures, airflow conditions and the working fluid.
The cause may remain in operating conditions, material compatibility, water hammer, vibration, corrosion or freezing.
For assessment: Record dates, previous repairs, replaced parts and changes in operation.
The separating surface may leak. An external visual inspection cannot rule this out.
For assessment: Describe the evidence of mixing and both fluids. Agree testing and further operation with the responsible specialist.
Fluid and deposits → materials and corrosion → flow and temperatures → pressure and water hammer → installation, vibration and previous assembly. Inspect the system as well as the exchanger.
One observation: pressure drop has increased
Check the condition of the channels and filters.
Compare flow and pump or fan operating conditions.
These are possible explanations, not a diagnosis. Compare equivalent operating conditions before choosing the work.
This tool collects inputs, suggests what to verify and prepares a request summary. It does not calculate test pressure, repair price or remaining service life.
Start with construction and symptoms. If you do not know the type, select “Not sure”.
These are comparison criteria, not automatic permission to repair. A decision depends on inspection and the requirements of the particular exchanger.
The same visible leak can lead to different decisions
Assess material condition, a suitable method and the ability to verify the result.
Compare wider damage, the system cause and the consequences of another failure.
| Criterion | Supports assessing repair | Supports comparison with replacement |
|---|---|---|
| Extent | One accessible defect. | Several damaged areas or recurring leaks. |
| Material | Condition and compatibility confirmed. | Corrosion, erosion, cracks or deformation. |
| Verification | The result can be verified after work. | The defect is inaccessible or repair quality cannot be verified. |
| Spare parts | Compatible parts and documentation are available. | Material is unknown or required parts are unavailable. |
| Consequences | The shutdown window and risk are acceptable. | Another failure would be critical to the process. |
| Economics | Repair, testing and downtime have been compared. | Cost and risk approach or exceed replacement. |
Replacement requires more than matching dimensions: connections, materials, fluids, operating conditions and allowable pressure losses are also needed.
What will demonstrate that the agreed work is complete?
Record identification, symptoms and operating conditions; assess the damaged area, surface condition and access.
Choose disassembly, mechanical or chemical cleaning to suit construction and materials. CIP is cleaning without disassembly, where the design allows it.
Agree gasket, plate, tube or section replacement; verify material compatibility and assembly instructions.
Apply an agreed test procedure. Record leak tightness and operating performance under comparable conditions.
Do not choose pressure-test settings or cleaning chemicals from generic website advice. They depend on documentation, materials, fluid and an approved procedure; a qualified specialist performs the work.
Show the entire exchanger, connections and access for removal.
Three views answer three different questions
What is the construction and how is it connected?
Which unit and documentation are involved?
Where is the observed problem?
Provide readable identification, documentation or a drawing if available.
A close-up and a wider view; describe when the symptom appears.
Also useful: fluids, temperatures, pressure, flow, pressure drop, cleaning and repair history, and the available shutdown window. Missing information can be marked as unknown.
Describe the task and prepare a request. If site submission is unavailable, copy the text or open it in email; attach photographs to the email manually.
A request is accepted only after the server responds with a request number. Preparing or copying an email does not send it.
info@upgradefor.comCompare the complete scope, including verification.
Cost depends on construction, fouling or damage, access, materials, disassembly, testing and logistics. Agree the final scope after reviewing inputs and assessing defects.
Photographs help identify construction and plan inspection. Hidden damage, materials, work scope and access may change an estimate.
No. Cleaning alone does not resolve flow, trapped-air, controls or damage issues. Compare results under equivalent conditions.
No. Construction, material condition, access and the ability to verify the result limit repairability. Replacement may be more appropriate.
Prepare overall and connection photographs, identification and a symptom description. Mark unknown values as unknown; do not guess allowable pressures.
The underlying cause may remain: operating conditions, fluid composition, corrosion, freezing, water hammer or vibration. Review previous work and inspect the system.
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