Heat exchanger repair is the work of finding why an exchanger has stopped doing its job, whether a leaking tube, a failed gasket, a cracked joint or a fouled surface that no longer moves heat, fixing it, and proving the unit tight and ready before it goes back on line. Paul Industries inspects, leak tests, cleans, regaskets, repairs, hydrostatically tests and reinstalls industrial exchangers for process plants and plant utilities across the United States, with most of the work on shell and tube and other tubular units. How a shell and tube unit is built and how its streams flow is explained in our shell and tube heat exchanger guide; gasketed plate units have their own cleaning, regasketing and repair detail on the plate heat exchanger page.
Why do heat exchangers fail?
Heat exchangers fail for six main reasons: fouling and scaling that insulate the tubes, corrosion that thins or pits the metal, erosion from high velocity or entrained solids, flow-induced vibration that wears tubes at the baffles, thermal stress from repeated or uneven temperature swings, and gasket failure at bolted joints. Several often act together: a deposit left in place frequently starts the corrosion that later causes the leak.
| Failure mechanism | Where it usually starts | What the operator sees | Usual response |
|---|---|---|---|
| Fouling and scaling | Cooling water side, hottest tube surfaces, low-velocity passes | Outlet temperature drifts, pressure drop climbs, duty falls | Chemical or mechanical cleaning; review velocity and water treatment |
| Under-deposit and pitting corrosion | Beneath scale, sludge or biofilm; stagnant zones left full during outages | Pinhole leaks, often several tubes in one area | Clean, inspect the tube walls, plug leaking tubes, correct the layup practice |
| Erosion | Tube inlets, opposite the shell inlet nozzle, U-bends | Thinning at tube ends, leaks clustered in the first pass | Plug damaged tubes, check flow rate against design, review inlet protection |
| Flow-induced vibration | Tubes at baffle holes, unsupported spans near the inlet | Noise, leaks at baffle locations, tubes worn in a ring pattern | Plug worn tubes, confirm shell-side flow has not been raised beyond design |
| Thermal stress and cycling | Tube-to-tubesheet joints, fixed-tubesheet units, steam heaters with frequent starts | Joint weeping that appears or worsens when hot | Tighten or repair joints, slow the warm-up rate, review condensate drainage |
| Gasket failure | Channel and bonnet joints, pass partition gaskets, floating head joints | External drips, or internal bypass that shows up as lost duty | Replace gaskets, inspect and clean faces, retighten in a controlled pattern |
Pass partition gasket failure is easy to miss, because nothing drips: fluid short-circuits from the inlet pass to the outlet pass inside the channel, and the unit looks fouled when it is not.
Signs an exchanger needs heat exchanger repair or cleaning
An exchanger needs attention when its approach temperature widens, its pressure drop rises beyond the clean baseline, the two fluids start to mix, or it leaks externally. Each points to a different cause, so log temperatures, flows and pressure drops before opening anything.
- Lost approach temperature. If the cold outlet falls further below the hot inlet than it did when new, at similar flows, heat transfer has dropped. Fouling is the usual cause, though internal bypassing looks the same. Comparing actual duty with the design duty, using our LMTD calculator, gives an overall heat transfer coefficient that can be trended.
- Rising pressure drop. A steady climb on one side, with no change in flow, means that side is losing flow area to deposits. A sudden jump points to debris at the tube inlets.
- Cross-contamination. Product showing up in cooling water, glycol turning cloudy, conductivity rising in condensate, or a tower that suddenly foams all suggest a tube or joint leak between the sides. The higher-pressure fluid flows toward the lower one, which tells you which stream to sample.
- External leaks. Drips at a channel, bonnet or shell flange usually mean gasket or bolting trouble that grows with each thermal cycle.
Can a heat exchanger be repaired?
Yes, most heat exchangers can be repaired, because the parts that fail first, the gaskets, individual tubes, tube-to-tubesheet joints and fouled surfaces, can be renewed or isolated without replacing the shell or the whole bundle. Leaking tubes are plugged at both ends, gaskets are replaced at every opening, weeping joints are tightened or resealed, and fouled surfaces are cleaned back to bare metal.
Some owners also weigh larger rebuilds. Retubing, where the old tubes are cut out and new ones are expanded into the existing tubesheets, is an industry method for a bundle whose shell, tubesheets and channels are still sound but whose tubes are thinning throughout. Which option fits depends on where the damage is concentrated, how many tubes are already plugged and how long the unit must still run.
Is it worth repairing a heat exchanger or replacing it?
Repairing a heat exchanger is worth it when the damage is local, the shell and tubesheets are sound, enough heat transfer surface will remain after repair, and the unit still matches the process duty; replacement wins when tube failures are widespread, the metallurgy is wrong for the service or the duty has outgrown the unit. The table sets out how those factors usually point.
| Factor | Points toward repair | Points toward replacement |
|---|---|---|
| Tube failures | A few tubes, in one area, with a known cause | Leaks spread across the bundle and recurring after each repair |
| Tubes already plugged | Well below the plant’s plugging limit; a common screening rule of thumb is around 10 percent of tubes | At or above the limit, so duty or pressure drop no longer meets the process |
| Wall thickness from inspection | Thinning limited to inlets or a few rows | General wall loss throughout the bundle |
| Shell, tubesheets and channels | Sound, with only gasket face cleanup needed | Cracked, heavily pitted or eroded beyond acceptable thickness |
| Materials | Suited to the fluids; the failure came from an upset or poor layup | Wrong alloy for the service, so the same corrosion will return |
| Duty | Process load and temperatures unchanged | Plant now needs more capacity, a closer approach or a different layout |
| Lead time and downtime | The line must be back within days | A planned outage allows time to install a replacement unit |
Plugging is a trade-off, not a free fix. Every plugged tube removes surface and forces the same flow through fewer tubes, which raises tube-side velocity and pressure drop. The plant’s own duty and pressure drop data, not a single percentage, should set the limit. When the numbers point to replacement, Paul removes the old exchanger, sets the new one and re-pipes it, with spools prefabricated through our pipe fabrication shop so the outage stays short.
How to find leak in shell and tube heat exchanger tubes and joints
A leak in a shell and tube exchanger is found by isolating the two sides, pressurizing one side, usually the shell, with the other side opened, and watching for liquid at each tube end and tube-to-tubesheet joint. Because the test fluid sits outside the tubes, a leaking tube or joint shows itself as water appearing at that exact hole in the tubesheet face, which is how the individual tube is identified for plugging.
- Fixed tubesheet units. With both channel covers or bonnets off, the shell is filled, vented and pressurized while both tubesheet faces are watched.
- U-tube units. Only one tubesheet exists, so both legs of each tube end at the same face. A leak at either leg points to the same tube, and plugging closes both legs.
- Floating head units. The floating head cover is removed and a test ring is fitted to seal the gap between the floating tubesheet and the shell, so the shell can be pressurized while the floating tubesheet face stays visible.
Water is the normal test medium because it stores far less energy than compressed gas. Weeps too slow to see under water can be found with a low-pressure gas test and soap solution on the tubesheet face. A separate tube-side test, with the bundle back in its shell, checks the channel gaskets and the pass partition. Test pressures and records are covered on our hydrostatic testing page.
| Test or inspection | What it finds | When it is used |
|---|---|---|
| Shell-side hydrostatic test, heads off | Leaking tubes and tube-to-tubesheet joints, located individually | Any suspected internal leak |
| Tube-side hydrostatic test, assembled | Channel, bonnet and pass partition gasket leaks | After reassembly, before return to service |
| Eddy current testing | Wall thinning, pitting and cracks in non-magnetic tubes such as copper alloys, titanium and most austenitic stainless | Condition assessment before leaks occur; repair vs replace decisions |
| Remote field testing | Wall loss in carbon steel and other magnetic tubes | Same purpose as eddy current, for ferromagnetic bundles |
| Internal rotary ultrasonic inspection (IRIS) | Measured remaining wall in most tube materials | Confirming and sizing indications found by faster methods |
Heat exchanger leak repair: plugging and joint work
On a tubular unit, the fix usually means plugging the failed tube at both ends with a plug of compatible material, or resealing a weeping tube-to-tubesheet joint. Plugs are matched to the tube alloy so they neither corrode galvanically nor loosen with heat, and each plugged position goes on a tubesheet map kept with the exchanger’s history, so the next inspection can see whether failures are spreading.
A plug stops one leak, but neighboring tubes saw the same conditions. When leaks cluster near the inlet nozzle or along one baffle line, Paul checks the surrounding tubes before closing up and reports the pattern, because the cause, often flow above design, will keep producing leaks until it is corrected.
What a shell and tube heat exchanger repair visit includes
A repair visit on a tubular exchanger runs from isolation and drain-down, through opening, cleaning, inspection, leak testing and repair, to reassembly, a hydrostatic test and a monitored return to service. The sequence below is how Paul typically plans one, whether it is a planned job or an urgent call.
| Step | What happens | What the plant receives |
|---|---|---|
| 1. Review and plan | Operating data, nameplate, drawings and past repair records are reviewed; gaskets and plugs are ordered to suit | Scope, outage duration and isolation points |
| 2. Isolate and lock out | Both sides isolated with blinds or double block and bleed, drained, vented and made safe for opening | Signed isolation under the plant’s permit system |
| 3. Open and inspect as found | Channel covers, bonnets or heads removed; deposits photographed and sampled before cleaning | As-found photos and deposit samples |
| 4. Clean | Chemical circulation, flushing or tube-side cleaning chosen to suit the deposit | Cleaning record with chemistry, times and results |
| 5. Leak test and locate | Shell side pressurized with heads off; leaking tubes and joints marked | Tubesheet map of leak locations |
| 6. Repair | Tubes plugged, joints resealed, gasket faces cleaned and checked | Updated tubesheet map and repair log |
| 7. Reassemble | New gaskets fitted; bolts tightened in a controlled sequence to target values | Bolting record |
| 8. Pressure test | Each side hydrostatically tested to the owner’s specified pressure and hold time | Test record with gauges, pressures and durations |
| 9. Return to service | Slow warm-up, vents checked, temperatures and pressure drop logged against the clean baseline | Post-repair performance baseline |
Bolted joint assembly follows the practices in ASME PCC-1: clean and examine the flange faces, lubricate the bolts, align the joint, center the gasket and tighten in passes using a cross pattern. Rushed bolting on large channel and floating head joints is a frequent cause of repeat leaks. Inside a wider outage, our shutdown and turnaround services team folds the exchanger work into the overall schedule.
Heat exchanger cleaning methods compared
The main options are chemical cleaning by circulation, clean-in-place on exchangers piped for it, high-velocity flushing, mechanical cleaning of the tube bores, and high-pressure water jetting of bundles; the right one depends on the deposit, the metallurgy and whether the exchanger can be opened. Many jobs combine an acid circulation with a flush that carries loosened material out.
| Method | Removes best | Exchanger stays assembled? | Points to know |
|---|---|---|---|
| Chemical circulation | Carbonate and other mineral scale, iron oxides, many organic films | Yes; temporary hoses connect at the nozzles | Reaches both sides, including shell sides that cannot be reached mechanically; chemistry must suit every metal in the circuit |
| Clean-in-place (CIP) | Product soils in food, dairy and pharmaceutical service | Yes; uses the plant’s CIP system | Validated cycles of rinse, caustic and acid; covered on our CIP and SIP systems page |
| High-velocity flushing | Loose silt, debris, biological slime, corrosion products | Yes | Often the last stage after chemical cleaning; reverse flow helps dislodge debris lodged at tube inlets |
| Mechanical tube bore cleaning | Soft and moderately hard deposits inside straight tubes | No; channel covers or bonnets removed | Brushes or scrapers sized to the tube; less suited to U-bends |
| High-pressure water jetting | Hard or thick deposits on tube bores and bundle exteriors | No; usually with the bundle pulled | A widely used industry method for heavy fouling; requires bundle handling and a contained wash area |
Shell and tube heat exchanger cleaning is hardest on the shell side, where baffles and tight tube pitch block access to the outside of the tubes. Chemical circulation solves that on fixed-tubesheet units, reaching every surface the process fluid touched.
Heat exchanger chemical cleaning procedure
A sound acid or alkaline clean identifies the deposit, chooses a chemistry the exchanger’s metals can tolerate, circulates it at controlled concentration and temperature while monitoring progress, then rinses, neutralizes and verifies that the surfaces are clean. Not knowing what the deposit is leads to cleans that fail or that damage the unit.
- Sample and analyze the deposit. A sample scraped from an inlet or nozzle shows whether the deposit is carbonate scale, silica, iron oxide, organic fouling, biological growth or a mix; mixed deposits often need two stages.
- Match chemistry to metallurgy. Every wetted material counts, including gaskets and any brass fittings. Hydrochloric acid can attack stainless steel quickly, so chloride-bearing acids are kept off stainless surfaces, and milder acids such as sulfamic, citric or phosphoric blends are chosen instead, always with a suitable corrosion inhibitor. Copper alloys and carbon steel each need chemistry chosen for them.
- Isolate and connect a circulation loop. The side to be cleaned is drained and connected to a temporary pump, tank and hoses, with a high-point vent so gas from the acid cannot collect in the upper tubes.
- Pre-rinse and, if needed, degrease. Loose debris is flushed out first. Where oils or organic films coat the scale, an alkaline stage removes them so the acid can reach the mineral layer.
- Circulate and monitor. The acid is added in stages and circulated. Strength, temperature and dissolved metals are checked at intervals. When acid strength stops dropping and gas evolution stops, the scale is gone, and continuing beyond that point only exposes clean metal to acid.
- Drain, rinse and neutralize. The spent solution is drained to containment, the exchanger is rinsed until the rinse water pH returns to normal, and a neutralizing rinse removes residual acid from crevices.
- Passivate where required. Stainless exchangers in hygienic or high-purity service are often passivated after acid cleaning to rebuild the protective oxide layer; see our passivation services.
- Verify and dispose. Pressure drop and, when back on line, approach temperature are compared with the baseline, and the spent chemistry is handled according to the plant’s discharge permit and local rules.
A clean done this way also leaves a useful record: the volume of scale removed, the chemistry and the time it took give a rate of fouling, which is the best guide to when the next cleaning will be needed. Sanitary units in dairy or beverage service follow their plant’s validated cleaning cycles instead; our pages on dairy heat exchangers and pasteurizers and sanitary heat exchangers cover those designs.
Heat exchanger tube cleaning on the tube side
Whatever method is used, a sound heat exchanger cleaning procedure starts with a deposit sample and ends with a measured result. Cleaning the tube side removes deposits from the bore of each tube, either chemically with the exchanger closed or mechanically with the channel covers or bonnets removed so every tube end can be reached. The tube side carries cooling water or the dirtier fluid in many exchangers, so it is where most fouling is found.
Before mechanical cleaning, fully blocked tubes and any inserts or ferrules are marked, and the tool is matched to the tube bore and material so the deposit comes off and the wall does not. Afterward, sample tubes are checked with a borescope for remaining deposit and pitting, which often reveals the cause, such as debris passing a failed upstream strainer.
Fouling inside tubes is strongly tied to velocity. Exchangers using water in the tubes are commonly designed for velocities of roughly 5 to 8 feet per second, and tubes that run much slower, because a pass was throttled or a pump was downsized, collect deposits faster. Shortening cleaning intervals call for a flow check before blaming the water treatment.
How often should a heat exchanger be cleaned?
A heat exchanger should be cleaned when its trended performance says so, typically when the heat transfer coefficient or approach temperature has degraded, or pressure drop has risen, to a trigger point the plant sets, rather than on a fixed calendar interval.
| Frequency driver | Shortens the interval | Lengthens the interval |
|---|---|---|
| Cooling water quality | High hardness, poor treatment control, open towers with airborne debris | Closed loops, well-controlled treatment, side-stream filtration |
| Velocity | Throttled passes, low flow at part load | Flow kept at design velocity year round |
| Wall temperature | Hot process fluid against hard water | Moderate temperatures, glycol or treated closed loops |
| Process fluid | Proteins, polymers, heavy oils, slurries | Clean, single-phase utility fluids |
| Operating pattern | Frequent starts, long idle periods filled with stagnant water | Steady continuous operation, proper drain or circulation during outages |
How often should heat exchangers be serviced?
Running units deserve a monthly performance check and a quarterly look at vents, drains and strainers, with a full opening every few years or as the inspection plan sets. The practical way to set a cleaning schedule is to log a clean baseline after each cleaning, trend the same readings monthly, and plan the next cleaning for an outage that falls before the trend reaches the trigger.
Maintenance of shell and tube heat exchanger equipment: checklist and schedule
Upkeep of these units combines regular performance trending and external checks while running with periodic opening, cleaning, inspection and testing during planned outages. Adjust the schedule below with the plant’s own history.
| Interval | Task | Why it matters |
|---|---|---|
| Each shift or daily | Walk-down for external leaks, unusual noise or vibration, gauge readings | Gasket weeps and vibration are cheapest to fix when found early |
| Monthly | Record inlet and outlet temperatures, flows and differential pressures; calculate approach and duty | Builds the fouling trend that sets cleaning dates |
| Quarterly | Check vents, drains, strainers, relief devices and supports; review water treatment results | Air binding, blocked strainers and poor treatment cause most fouling problems |
| At trend trigger | Clean the fouled side; record the deposit type and amount | Restores duty and shows the fouling rate |
| Planned outage, every few years or per inspection plan | Open, inspect, nondestructive tube testing, leak test, replace gaskets | Measures remaining tube life and supports repair vs replace decisions |
| Before any extended shutdown | Drain and dry, or keep circulating with treated water | Stagnant water is a leading cause of pitting during idle periods |
A good heat exchanger maintenance program is tied to the chillers, glycol loops and steam systems the exchangers serve. Paul includes exchangers in plant-wide preventive maintenance programs and service contracts, and coordinates them with chiller repair when a fault spans both machines.
Shell and tube heat exchanger troubleshooting
Shell and tube heat exchanger troubleshooting starts by comparing present temperatures, flows and pressure drops with the clean baseline, then matching the pattern to its likely cause before anything is opened.
| Symptom | Likely causes | Check first | Typical fix |
|---|---|---|---|
| Duty low, pressure drop normal | Pass partition bypass, air binding, shell-side bypass around baffles, wrong flow | Vent the high points; confirm flows; compare both sides’ pressure drops | Vent, replace pass partition gasket, correct flow balance |
| Duty low, pressure drop high | Fouling or scaling on the high-drop side | Trend history; deposit sample from a nozzle | Clean by the method that suits the deposit |
| Contamination between fluids | Tube leak, tube-to-tubesheet joint leak | Sample both streams; note which side runs at higher pressure | Leak test with heads off; plug or reseal; pressure test |
| Leak appears only when hot | Thermal expansion opening a joint, gasket relaxation | Warm-up rate; bolt condition; joint location | Replace the gasket, retighten in sequence, slow the warm-up |
| Banging or hammering in a steam heater | Condensate backing up into the shell, failed trap, undersized drain | Trap operation; condensate level; control valve behavior | Restore drainage, repair the trap, review the control setup |
| Repeated tube leaks in one area | Erosion or vibration from flow above design, inlet impingement | Flow against design; leak map history | Plug tubes, reduce flow or add protection, assess the bundle |
What drives heat exchanger repair cost
Heat exchanger repair cost is driven mainly by how much of the unit has to be opened and handled, what the inspection finds, the materials involved, access at the site and how quickly the exchanger must be back in service.
- Size and design. Large channel covers and floating heads need rigging and test rings; small bonnet units open quickly.
- Access. Units in pipe racks or tight plant rooms need scaffolding, cranes or extra time.
- Deposit. Hard or mixed deposits may need two chemical stages and more disposal.
- Inspection scope. Testing every tube costs more than a sample but better supports a repair vs replace decision.
- Materials. Alloy plugs and special gaskets lengthen lead times.
- Timing. Night, weekend and emergency work costs more than a planned outage.
When an exchanger fails without warning, our emergency repair service mobilizes to isolate, find and fix the leak and get the line running.
Choosing heat exchanger repair companies
When comparing contractors, look for crews who can do the whole job on your site, from isolation and opening through cleaning, leak testing, repair, bolting and the final pressure test, and who hand back written records of each step. Splitting those tasks adds handoffs and leaves no one answerable for a tight restart.
Questions worth asking any heat exchanger cleaning company or repair contractor:
- How do you identify the deposit before choosing a chemistry, and how do you confirm the chemistry is safe for every metal in the exchanger?
- What test method will you use to locate leaks on this exchanger type, and what pressure and hold time will you test to?
- Will we receive a tubesheet map, cleaning record, bolting record and test record?
- Can you also replace and re-pipe the exchanger if the inspection points that way?
The better heat exchanger maintenance companies also look past the failed part to its cause, so the repair is not repeated next year. Plants comparing heat exchanger cleaning services should ask for post-cleaning pressure drop and duty readings.
Industrial heat exchanger repair from Paul Industries
Paul Industries repairs and cleans exchangers for process plants and utility systems nationwide. Our crews isolate and open shell and tube, tubular and plate exchangers; sample deposits and clean by chemical circulation, flushing or clean-in-place on units piped for it; leak test and locate failed tubes and joints; plug leaking tubes; replace gaskets and reassemble with controlled bolting; and hydrostatically test each side before return to service. When a unit is beyond repair, we replace and re-pipe it and support startup.
A single shell and tube heat exchanger service call, a heat exchanger cleaning service on a set schedule, or ongoing heat exchanger repair services under a maintenance program are all handled by the same crews, so the history of each unit stays in one place. New installations are covered on our heat exchanger page. To schedule an inspection, a cleaning or an urgent repair, request a quote with the exchanger’s nameplate data, the symptoms you are seeing and your outage window.
Standards referenced: ASME Boiler and Pressure Vessel Code Section VIII · TEMA Standards · ASME PCC-1
Frequently asked questions
What does a routine service visit on a running exchanger cover?
A walk-down for leaks, noise and vibration; readings of inlet and outlet temperatures, flows and pressure drops compared with the clean baseline; checks of vents, drains, strainers and relief devices; a sample of the lower-pressure stream for signs of a leak; and a short report that flags anything trending toward a cleaning or repair.
How many tubes can be plugged before an exchanger stops doing its job?
There is no single number. A screening rule of thumb used in industry is around 10 percent of the tubes, and many units tolerate 5 to 10 percent before duty suffers. The real limit is whether the remaining tubes still deliver the required heat transfer at an acceptable pressure drop and tube velocity.
Can a leaking exchanger be repaired without removing it from the line?
Usually yes. Most tube plugging, gasket replacement and joint work is done in place once both sides are isolated and the channel covers or bonnets are removed. Removal is needed when the bundle must be pulled, the exchanger is being replaced, or the location gives no room to work on the heads.
How long does a typical exchanger repair take?
A gasket replacement on a small unit can be done within a shift. A visit that includes chemical cleaning, a heads-off leak test, plugging and a hydrostatic test on a mid-size exchanger commonly takes two to four days, driven by access, rigging, cleaning time and test hold periods.
What pressure is used to test an exchanger after repair?
The owner's inspection program and the applicable jurisdiction set the test pressure, based on the exchanger's nameplate rating. For context, new vessels built to current ASME Section VIII Division 1 are shop tested hydrostatically to at least 1.3 times the maximum allowable working pressure, adjusted by the material stress ratio.
Is acid cleaning safe for stainless steel tubes?
It is safe when the acid is chosen for stainless and inhibited, the strength and temperature are controlled, and the exchanger is rinsed and neutralized afterward. Chloride-bearing acids such as hydrochloric are kept off stainless because they can cause rapid pitting. Passivation afterward helps in hygienic service.
What happens to the spent cleaning solution?
It is drained to containment, neutralized and disposed of according to the plant's discharge permit and local regulations. Spent acid can carry dissolved metals from the exchanger, so it is tested before release, and some solutions must be hauled off site rather than sent to the plant drain.
How do you know a cleaning worked?
Pressure drop on the cleaned side should return close to the clean baseline, and once the unit is running, approach temperature and calculated duty should recover. Borescope or visual checks of sample tubes confirm bare metal. Recording these readings creates the baseline for the next fouling trend.
Should gaskets be replaced every time the exchanger is opened?
Yes. Compressed gaskets take a permanent set and rarely seal reliably a second time, especially after thermal cycling. New gaskets of the correct material and dimensions are fitted at each opening, including the pass partition gaskets that cannot be seen once the unit is closed.
What causes a tube-to-tubesheet joint to start leaking?
Repeated thermal cycling, differential expansion in fixed-tubesheet units, corrosion in the crevice behind the joint, vibration and damage during earlier work are the usual causes. Joints that weep only when the unit is hot point toward expansion or cycling as the driver.
What tube inspection finds thinning before it becomes a leak?
Eddy current testing is used for non-magnetic tubes such as copper alloys, titanium and most austenitic stainless steels. Remote field testing covers carbon steel and other magnetic tubes. IRIS ultrasonic inspection measures remaining wall directly and is often used to confirm indications from the faster methods.
Can an exchanger without CIP connections be cleaned in place?
Often it can. Temporary hoses, a portable circulation pump and a tank are connected at the existing nozzles or at valved drain and vent points, and the chemical is circulated with the exchanger still installed. Adding permanent cleaning connections during a later outage makes future cleanings faster.
Does a repaired stainless exchanger need passivation?
It is recommended when acid cleaning, grinding or welding has disturbed the stainless surface, and it is routine for exchangers in hygienic, pharmaceutical or high-purity water service. Passivation removes free iron and restores the chromium oxide layer that gives stainless its corrosion resistance.
When should an exchanger be repaired right away instead of at the next shutdown?
Act immediately when one fluid is contaminating another in a way that affects product safety, the environment or downstream equipment, or when an external leak involves a hazardous or hot fluid. A slow loss of duty or a minor external weep can usually be managed until a planned outage.
What information helps a contractor plan a repair visit?
Nameplate data or the datasheet, drawings if available, recent temperatures, flows and pressure drops, the symptoms and when they started, past repair records and tubesheet maps, the fluids on each side, and the outage window. Photos of the exchanger and its access route help with rigging and scaffolding plans.
Can fouling be reduced so cleaning is needed less often?
Yes. Keeping tube velocity at design, maintaining good water treatment, fixing upstream strainers and filtration, avoiding throttled passes, and draining or circulating during idle periods all slow fouling. Trending performance shows which change made the biggest difference.
Why does a heat exchanger lose capacity even after cleaning?
If duty stays low after a successful clean, look for internal bypassing at a pass partition gasket, a damaged baffle or seal strip, air trapped at high points, too many plugged tubes, or a change in flow or inlet temperature since the unit was designed.
Do plugged tubes affect pressure drop?
Yes. Plugged tubes remove flow area, so the same flow is forced through fewer tubes at higher velocity, which raises tube-side pressure drop and can increase erosion at the tube inlets. That is one reason plugging is tracked against a limit.
Related: Plate Heat Exchanger · Sanitary Heat Exchanger Installation & Service · Sanitary Heat Exchangers: Types & How They Work · Dairy Heat Exchangers And Pasteurizers · Food And Beverage Heat Exchangers · Hydrostatic Testing · Request a quote