Industrial plate, shell and tube heat exchanger cleaning

Heat exchanger cleaning

Heat exchanger cleaning removes the fouling that has cost a unit its duty, in place or off site. Send the unit details and what has built up on it, and a specialist who cleans that type will come back to you. Coverage is UK wide.

CoverageUK wide
Unit typesPlate, shell and tube, air cooled
ResponseBreakdown and planned shutdown

Submit a cleaning request

Four steps: unit, deposit, postcode, contact details.

01Unit
02Situation
03Site
04Contact

01The first decision

Cleaning in place keeps the unit on the pipework, stripping it out proves its condition

Answer this and most of what follows is settled. In place, the unit never leaves the pipework and can be back in service overnight. Off site, it goes away for days and every plate or tube is inspected before it comes back.

Clean in placeChemistry circulated through the unit's own connections. Nothing comes apart, nothing leaves site, and the plant is often running again by morning.Right whenThe deposit dissolves and you need the unit back.ButIt tells you nothing about the state of the plates or tubes.Read more →Strip and clean off siteThe pack or bundle comes out. Every surface is cleaned and inspected on its own, then re-gasketed and pressure tested before it goes back.Right whenYou need to know the condition, or you suspect a cross-leak.ButThe unit is gone for days, and something has to cover the duty.Read more →Not sureWhere most enquiries start. The unit and the deposit usually settle it between them, and all five methods are compared side by side.Right whenYou have the symptom but not the diagnosis.ButNaming the deposit narrows it fastest.Read more →

02What gets cleaned

Plate packs and tube bundles foul differently, so they are cleaned differently

The unit decides what follows: whether it can be cleaned on the pipework, what the deposit can be attacked with, and what condition it can be certified in when it goes back.

Gasketed plate packs come apart for inspection, brazed and welded packs do not

A gasketed plate heat exchanger fouls in the herringbone troughs where the flow is slowest, and the first symptom is usually a rising differential pressure, not a lost approach temperature. Stripped, each plate is cleaned individually, then checked for thinning, pitting and cracking before it goes back in the frame. Dye penetrant testing on a stripped pack finds the cracks that cause cross-contamination between circuits, which is the failure that a circulation clean cannot detect.

Brazed and semi-welded units have no gasket line to open, so they are cleaned by circulation, back-flushed, and judged on flow and pressure drop instead of on sight. Welded plate packs sit between the two: the pack cannot be separated plate by plate, but access ports allow lancing and chemical soaking that a brazed unit will not take.

Fouls where: Trough contact points, inlet ports, slow-flow lanes
First symptom: Rising differential pressure across the pack
Comes back: Plates gauged, gasket set assessed, pack pressure tested

Tube bore, tube sheet and shell side each need a different tool

Shell and tube fouling is rarely uniform. The tube bores take the process-side deposit and are cleaned by lancing. That means high pressure water through a rigid or flexible lance, or a rotating brush or scraper where the deposit resists water alone. The tube sheet face collects a different deposit again and is usually the part that tells you how bad the bores will be before a single lance goes in.

The shell side is the harder half. With the bundle in place, only circulation reaches it. With the bundle withdrawn, the outside of the tubes and the baffle spaces can be jetted directly. It is the only way to shift baffle-window deposits and the sludge in the bottom of the shell. Bundle extraction is the decision that governs the timescale, because the plant has to accommodate the pull.

Fouls where: Tube bores, tube sheet face, baffle windows, shell floor
First symptom: Widening approach temperature, falling U-value
Comes back: Bores gauged or bore-scoped, bundle inspected, unit tested

Air coolers, condensers and spiral units foul on the air side as often as the process side

Air-cooled exchangers and finned coils lose duty to what the fan pulls through them: dust, pollen, insects, oil mist and, on coastal sites, salt. The fin block is cleaned from the outlet side back so the debris comes out the way it went in instead of being driven deeper into the pack. Bent fins get combed, because a flattened fin field costs airflow long after the dirt has gone.

Condensers, evaporators and chillers foul on the water side with scale and biofilm, and on the refrigerant side with oil carry-over. Spiral heat exchangers are built for dirty and fibrous duties and are cleaned by back-flushing the channel or by opening the covers and lancing the spiral directly.

Fouls where: Fin block, condenser tubes, spiral channel, oil side
First symptom: Rising head pressure, higher fan or compressor load
Comes back: Fin field combed, tubes gauged, circuit leak checked

03How it is done

Four methods cover the range and each one is wrong for something

Having chosen in place or off site, the deposit decides which tool inside that choice removes it.

In place

CIP circulation dissolves fouling without breaking the pipework

A pump, a tank and a heater are connected to the unit's existing connections, and a cleaning solution is circulated through it. Usually hot, and usually reversed part way through so the flow attacks the deposit from both directions. It is the fastest route back to duty, and on a unit that cannot be isolated for long it is often the only route.

Right whenThe deposit is soluble, the unit is accessible, and downtime matters more than certainty.
Wrong whenPlate condition is in doubt, the deposit is baked or fibrous, or the unit is suspected of cross-leaking.

Off site

Off-site strip and immersion returns a plate pack that has been seen

The pack is broken down, and every plate is soaked, cleaned and inspected individually before the frame is rebuilt. It takes the unit out of service for longer and it costs more, and in exchange it is the only method that produces evidence about the plates themselves and not about the flow through them.

Right whenThe unit has never been stripped, is cross-contaminating, or is due gaskets anyway.
Wrong whenThere is no spare, no shutdown window, and the fouling is known to be soft scale.

Mechanical

Hydro jetting cuts hard deposits out of tube bores without chemistry

High and ultra-high pressure water, running to around 2,800 bar on the heaviest duties, is directed down each tube through a lance or a rotating head. It removes coke, hard scale and polymer that no economic chemical soak will shift, and it does it without leaving the site a spent acid stream to dispose of.

Right whenThe deposit is hard, the tubes are straight and accessible, and chemical disposal is a problem.
Wrong whenTube walls are already thinned, or the geometry stops a lance reaching the full length.

Mechanical

Ultrasonic and mechanical cleaning reach what water and chemistry miss

Ultrasonic immersion works cavitation into fin blocks, small-bore cores and complex geometry that a lance cannot enter, and it does it without abrading the surface. Rotary brushing, scraping and drilling handle the opposite case: a bore so hard-blocked that nothing can be circulated through it at all.

Right whenGeometry is complex, cores are small-bore, or a tube is fully blocked.
Wrong whenThe unit is too large for the tank, or the deposit is soft enough for circulation.

04What has built up

The deposit decides the chemistry, the method and how long the unit is down

Naming the deposit is the difference between a specialist quoting a method and a specialist quoting a survey.

Deposit	Where it comes from	How it is removed
Scale and hard water	Calcium and magnesium carbonate dropping out of cooling water as it heats. Worst on the hot side and at the outlet.	Acid circulation, or jetting where the layer is thick and hard. CIP / UHP
Biofilm and microbial	Untreated or under-dosed cooling water, seawater and open towers. Thin, slimy, and disproportionately insulating.	Alkaline or oxidising circulation, then a biocide programme to stop it returning. CIP
Oil, grease and hydrocarbon	Lube and quench oil coolers, compressor circuits, and any duty where oil crosses to the water side.	Hot alkaline or solvent circulation, degreasing off site where it has carbonised. CIP / immersion
Coke and carbon	Crude preheat trains, furnace and reactor service. Thermal cracking bakes residue hard onto the tube wall.	Ultra-high pressure jetting, or mechanical drilling where a bore is fully blocked. UHP / mechanical
Protein and beerstone	Pasteurisers, wort coolers and paraflows. Calcium oxalate and denatured protein bond to the plate surface.	Two-stage caustic then acid circulation, or strip and immersion once it has layered. CIP / immersion
Corrosion products	Iron oxide and magnetite from carbon steel pipework carried into the exchanger and deposited in slow-flow areas.	Inhibited acid or chelant circulation, with the source treated or the unit refouls. CIP
Process solids	Fibre, catalyst fines, polymer, sand and silt. Blocks ports and channels instead of coating them evenly.	Back-flushing and jetting. Chemistry does very little to something that was never dissolved. UHP / back-flush

05What happens next

Four steps take a fouled unit from enquiry to a tested return

The enquiry goes straight to a contractor who cleans that unit type. There is no qualifying call in between.

You send the unit details, the deposit and the postcode.
The enquiry goes to a specialist set up for that unit type and that fouling.
They come back with method, timescale and price.
The clean is carried out in place or off site, and the unit is tested before it goes back.

06Industries

Fouling follows the process, so every sector fouls its exchangers differently

What builds up in a brewery paraflow has nothing in common with what builds up in a crude preheat train, and the two are not cleaned the same way.

07Coverage and response

Cleaning teams cover the UK for breakdowns and planned shutdowns

UK wide

Cleaning teams cover mainland UK, including the industrial clusters on Teesside, the Humber, Merseyside, the Solent and the Firth of Forth.

Breakdown response

A unit that is already down is treated as a breakdown, and the enquiry is routed to a team with capacity rather than added to a queue.

Planned shutdowns

Turnaround and shutdown work is scheduled ahead, so the bundles are pulled, cleaned and back before the window closes.

08Compliance and safety

The work is carried out to confined space, COSHH and permit-to-work requirements

These are the standards the work is carried out to on an industrial site.

Permit to workCleaning teams work to the site's own permit system, isolation and lock-off procedures.
Confined space entryShell entry and vessel work are carried out under confined space procedure with rescue provision in place.
COSHHCleaning chemistry is assessed under COSHH, and spent solution is removed and disposed of under duty of care.
Water jettingHigh and ultra-high pressure jetting follows Water Jetting Association codes of practice and exclusion zones.
CDM where it appliesWhere the clean forms part of a construction or turnaround project, CDM duties apply and are assigned.
Test before returnUnits are pressure tested and inspected before they are returned to service. Written records go with them.

09Questions

Cost, downtime and gasket replacement are the questions that decide the job

How long does a heat exchanger clean take?

A clean in place on an accessible unit with soluble fouling is usually a single shift: connect, circulate hot, reverse the flow, rinse, and hand back. Overnight is common so the plant loses no production time at all.

A strip and clean off site is measured in days, not hours. Breaking the pack, cleaning and inspecting each plate, renewing gaskets, curing them, rebuilding and pressure testing is a sequence that cannot be usefully compressed. Transport each way and the size of the unit are usually what move the number.

Do the plates have to come out?

No, and often they should not. If the deposit is soluble and the plate condition is not in question, circulation restores the duty faster and for less money.

They have to come out when you need to know something about the plates, not about the flow. That means four cases: a suspected cross-leak between circuits, a unit that has never been opened, fouling circulation has already failed to shift, or gaskets at the end of their life.

Can a gasketed plate heat exchanger be cleaned in situ?

Yes. A gasketed unit is designed to be opened, but that does not mean it has to be opened to be cleaned. CIP through the existing connections is routine on gasketed packs and is usually the first attempt.

The limit is what circulation can reach and dissolve. It will not shift a baked or fibrous deposit, and it will tell you nothing about plate thinning or hairline cracking, so a unit that is cross-leaking gets stripped, not circulated.

Are gaskets replaced when a pack is stripped?

Not automatically. Gaskets that are sound, in date and not bonded to the plate are re-used. The strip is inspected, and the gasket set is assessed plate by plate.

Where they do need renewing, doing it during a clean is the cheap moment: the pack is already open and the strip labour is already paid for. Renewing a set later means paying to break the same unit down a second time.

Is the unit pressure tested before it goes back into service?

Yes, where the pack has been opened. A rebuilt plate pack is pressure tested before it returns, and on shell and tube work the bundle and shell are tested after cleaning, with records issued.

A clean in place does not disturb the pressure envelope, so it does not generate a test in the same way. What it should generate is before-and-after flow and differential pressure figures showing the duty came back.

How often does a heat exchanger need cleaning?

Frequency should be set by measurement and not by calendar. The useful triggers are differential pressure across the unit, approach temperature, and calculated U-value against the clean baseline. When any of them drift past the threshold set for that duty, the unit is due.

In practice, duties on treated closed-loop water can run years. Open cooling water, seawater and heavy process duties often need annual or shutdown-cycle attention, and some fouling-limited services are cleaned every few months by design.

What does heat exchanger cleaning cost?

It depends on three things, and there is no way to quote without them: the unit, the deposit, and the access.

Unit sets the scale, a 40-plate package unit and a 900-plate dairy pack are not the same job. Deposit sets the method, and jetting coke out of a tube bundle is not priced like circulating acid through a scaled plate pack. Access decides whether a team can work on it where it stands or whether it has to be rigged, lifted and transported.

A specialist with the unit type, the deposit and the postcode can usually give a real number. Without them, any figure is a guess.

Can a unit be cleaned while the plant is running?

Only where the exchanger itself can be isolated while the process continues, which normally means a duty-standby pair or a bypass. Where that exists, CIP on the offline unit is routine and the plant never stops.

On a single unit with no bypass, cleaning needs an isolation window. Plan it into a shutdown instead of waiting for the duty loss to force it. An unplanned clean on a unit that has already failed takes longer than the same clean scheduled.

A specialist who cleans that unit type answers the request

Unit, deposit and postcode are enough to start. Your details go to a specialist who cleans that unit type. No obligation.

Arrange a clean