Large shell and tube heat exchangers mounted in a refinery pipe rack against a deep blue evening sky, an engineer on the walkway between them

Equipment

Air-cooled heat exchanger repairs

Air-cooled heat exchanger repairs restore coolers that have stopped shifting heat. Send the nameplate and what has happened, and a specialist who works on that type will come back to you. Coverage is UK wide.

Step 1 of 2

Tell us about your air-cooled heat exchanger repairs

Five answers, all from memory. The detail comes next, and it is optional.

See the privacy notice for how these details are handled.

Common air cooler problems

Losing duty

It is no longer cooling

Blocked airways, bent or fouled fins, and air flow that has fallen away.

Cleaning options →Planned

A service or shutdown is coming

Planned work, an outage window, or a unit nobody has opened for some time.

Servicing options →Plant down

It has failed or is leaking

Fluids mixing, a leak at the unit, or one that will not hold pressure.

Emergency repair →Unsure

Not sure what is wrong

Send the nameplate and what you have noticed. That is enough to get an answer.

Send the details →

What goes wrong with air-cooled units

Air-cooled heat exchanger repairs cover air blast coolers, fin fan units and finned coils. Fin side fouling takes the duty away long before anything leaks, so lost cooling and a leak are usually two different jobs.

Fin side fouling. Dust, pollen, insects, oil mist and cottonwood packing the fin block. Fin side fouling does not leak, does not alarm, and can take a large share of the duty. Fin side fouling is by far the most common problem on an air cooler, and the most often missed.
Fin bond degradation. Where the fin loses contact with the tube, heat transfer falls even though the fin block looks intact. Corrosion between fin and tube, or thermal cycling, both cause it, and it is not fixable by cleaning.
Header plug leaks. Plug type headers have a threaded plug opposite every tube end, each with a gasket. Those gaskets are a recurring leak path, particularly after thermal cycling, and are a routine maintenance item rather than a fault.
Tube failures. Internal corrosion or erosion the same as any other exchanger, but harder to find, because the tube is buried in fins and cannot be inspected from outside.
Fan and drive faults. Belt wear, bearing failure, blade pitch drift and vibration. Not a heat exchanger fault at all, but the first thing to rule out when duty has fallen and the bundle looks clean.

Air-cooled heat exchanger repair options

Clean the fin block: Washing through the bundle in the right direction, at a pressure the fins survive. Over-pressure flattens fins, which reduces airflow and makes the problem worse than the fouling did.
Replace header plug gaskets: Straightforward, and worth doing as a set while the header is open, instead of one at a time as each starts weeping.
Plug or replace tubes: Individual finned tubes can be plugged, and can be replaced where the bundle construction allows. Access is the constraint, not the technique.
Rebundle: Where fin bond has gone across the bundle, or corrosion is general, the bundle is replaced. Lost duty is a genuine cost, so a performance test is worth having before the appearance of the block is trusted.

What to check before an air cooler repair

A fin block can look clean from the face and be packed solid in the middle, so the honest check is the temperature difference across the bundle rather than a visual one
Washing from the wrong side drives the debris further in rather than out
High ambient temperatures reduce duty on every air-cooled unit, so a summer performance complaint is not always a fault
Fin bond loss does not show on any visual inspection, and the unit will keep looking serviceable while underperforming

Questions