We restore worn air coolers and upgrade them when the process has outgrown the original design. Re-tubing, bundles, finned tube and spare parts come from Spiro-Gills Thermal Products in Stafford, supplied and supported in the GCC by Petromarsh.
Tap a part to see what it does. The red rows are the tubes being replaced, the blue arrows show the bundle being lifted out of the bay.
Lifting. The bundle is lifted out on a spreader beam from its lifting lugs, so the tubes are not bent. The lift plan is agreed before the shutdown.
Bundle. The tube bundle in its side frames. It can be re-tubed, partly re-tubed, or replaced with a new bundle that fits the same bay.
Re-tubed rows. Damaged or thinned tubes are cut out and new finned tubes are expanded or welded into the tubesheets. A full re-tube replaces every tube.
Headers and plugs. Plugs are removed to reach each tube. Plug threads and gasket faces are checked, and new plugs and gaskets are fitted.
Bay, fan and drive. While the bundle is out, the plenum, fan, hub, belts, bearings and motor are inspected and worn parts are replaced.
Spare parts. Plugs, gaskets, finned tube, fan blades, hubs, belts and bearings, held for the next shutdown.
Air coolers wear from the inside, by corrosion and erosion of the tubes, and from the outside, by fin damage, fouling and drive wear. The right answer depends on what has failed and on what the process now needs.
Keep the headers and side frames, and replace some or all of the finned tubes. Often the best value when the headers are sound.
A new bundle built to fit the existing bay, nozzles and structure. The fastest way back to service, with the old bundle kept as a spare or scrapped.
When throughput or ambient has grown beyond the original design, the HTRI design is rerun. More rows, better fins, a new tube material or bigger fans can restore the margin.
Spiro-Gills can work from the original drawings, or measure the old bundle where none exist. Tap a service to see what it covers.
Damaged tubes are removed and new finned tubes fitted into the existing headers. A full re-tube restores the bundle, and new fin types can be fitted at the same time.
A complete new bundle designed to fit the existing structure, nozzles and fans. It can be built before the shutdown, so the plant is down only for the swap.
The HTRI design is rerun against today's flow and ambient. Extra tube rows, a different fin, higher fan power or new pitch control are then chosen to restore the margin.
Common in the Gulf, where design ambient used for older units is often lower than today's summers.
Replacement fans, D-series and E-series axial fans, Howden-matched fan casings, hubs, belts, sheaves, bearings and vibration switches.
Header plugs and plug gaskets in carbon or stainless steel and soft metals, matched to the header threads and material.
Welded finned tube from Spiro-Gills to your tube and fin specification, for re-tubing in your own workshop or by a contractor.
Tube inspection, fin condition checks, fan and drive surveys, and cleaning of fouled fins. Advice on washing fins after sand and dust.
Replacement parts are made from the original materials, or from better ones where the old material has failed.
| Part | Carbon steel | Stainless and duplex | Other options |
|---|---|---|---|
| Header boxes | Plate, forgings and pipeSA-516 Gr 70 · SA-105 · SA-106 Gr B | 304L, 316L, duplex 2205SA-240 · SA-182 · SA-312 | Low-temperature carbon steel, impact testedSA-516 with SA-20 · SA-333 · SA-350 LF2 |
| Tubes | Seamless or weldedSA-179 · SA-214 · SA-334 | 304L, 316L, duplexSA-213 · SA-249 · SA-789 | Admiralty brass, copper-nickelSB-111 |
| Fins | Aluminium, the usual choice1000-series aluminium strip | Stainless steel welded finsfor hot or corrosive air | Copper fins, or galvanised carbon steel welded finshot-dip galvanised |
| Plugs and gaskets | Shoulder plugs in carbon or stainless steel, with soft iron, aluminium, copper or stainless gaskets matched to the header materialSA-105 · SA-182 | ||
Repairs follow the code the cooler was built to, plus the inspection rules your site uses.
Requirements for air-cooled heat exchangers in petroleum, petrochemical and natural gas plants: headers, tubes, fins, fans, drives and structure.
Pressure design of the header boxes, plugs and nozzles, with the U stamp where it is required.
Inspection of pressure equipment in service, used by many sites for coolers and their headers.
Repair methods for pressure equipment and piping.
Assessing whether worn or damaged equipment can stay in service.
Rating software from Heat Transfer Research, Inc. Not a code, but the industry reference for air-cooler thermal design.
Material specifications, and qualified welding procedures and welders for headers and tube-to-tubesheet joints.
Non-destructive testing methods, and certified mill certificates for every pressure part.
CE marking for Europe. UKCA under the Pressure Equipment (Safety) Regulations 2016 for the UK.
Your engineers red-line our drawings, you approve the design twice before production starts, and you can witness the tests. Tap a step to see what happens and which documents you receive.
Spiro-Gills Thermal Products has designed and built bespoke air-cooled heat exchangers and finned tube in Stafford since 1946, and has supplied them to more than 100 countries. Thermal design is done in HTRI, welding is to ASTM code, and the company holds ISO 9001:2015. Petromarsh is their exclusive representative in the GCC.
Old drawings and photos help most. If you have none, the items on the right are enough to start, and the bundle can be measured.
