Heat Exchanger Release & Protective Coatings

Curran International coated tube applications are globally known to prevent fouling in heat exchangers. For more than 25 years Curran’s proprietary applications of a low surface energy tube ID coatings have eliminated deposit nucleation down tube, reducing heat exchanger fouling and cleaning.

Using highly functional immersion service coatings Curran applies a thin film, homogenous film down tube. The coated tube has a greatly reduced surface tension compared to uncoated steel and is inert to cooling water. Curran coatings are hydrophobic and create a high contact angle; immersion resistance to 365F gives the Curran coatings durability to periodic operating unit steam out.

Exchanger tube bundle coated using baked phenolic downtube and across tubesheet
Exchanger tube bundle coated using baked phenolic downtube and across tubesheet

For cooling water, tube coating protects from deposit corrosion, and Curran delivers a “holiday free” application at 200 to 300 microns total thickness. Curran applies heat exchanger coating to shell & tube exchangers, tube bundles, U tube and plate and frame exchangers. Tube sheet coating – as part of the Curran tube coating application – protects tube ends, and the integrity of the roller expanded tube joint.

Refinery and petrochemical clients have found exchanger tube ID coatings can immediately solve “bad actor” exchanger reliability where low flow, deposit accumulation limit the functional life of an asset. Curran heat exchanger internal coatings are specified as a value add for replacement exchangers, and are a lower cost option compared to an alloy upgrade.

Curran has continued to develop its portfolio of thin film coating materials suited to a wide range of industrial services; cooling water, crude and hydrocarbon products, solvent and acid services. Sol Gel and hybrid materials are functional at < 25 microns total thickness. These ultra-thin applications are solutions for operation critical exchangers where crude and hydrocarbon services are primary causes of fouling in heat exchangers and can be applied to exchanger tube IDs, ODs and plate and frame exchangers.

Curran can identify the best coating for operating unit conditions, and provide an application procedure and quality control report for surface prep, coating application, and inspection. The coated tube ID application is performed after the exchanger has been fabricated, the complete exchanger or tube bundle is coated, either at one of Curran’s global coating plants or in the field.

Restoration of in-service, corroded exchangers is a practical repair strategy that Curran has years of successful project experience. It starts with “clean white metal” surface prep of exchanger, and remediation of soluble contaminants. Many of Curran tube coatings can be field applied, and force cured.

Low voltage holiday testing Curran 1000T coated exchanger
Low voltage holiday testing Curran 1000T coated exchanger

The benefits of tube ID coating are known by refinery and petrochemical clients across the globe. Refinery bad actor bundles are likely poor performing exchangers due to the effects of fouling in heat exchangers. Equipment engineers specified heat exchanger coating to replace “in-kind” fabricated tube bundles using Curran tube ID coating; benefits were found in years of reduced maintenance, continuous operation run, and improved operating reliability.

Curran is at the forefront of material and application technology development using advanced polymers and inorganic/hybrid coatings. Ultra thin (<25 micron) applications are solutions for operation critical exchangers where crude and hydrocarbon services are primary causes of fouling in heat exchangers. These new advanced technologies can be applied to exchanger tube IDs, ODs and plate and frame exchangers.

All heat exchanger internal coating applications are subject to Curran quality control, and inspection observation and record points. We coat shell & tube exchanger bundles, air coolers, U tube and plate and frame exchangers; provide in-service exchange tube ID restoration; tube end coating, plate exchangers, OD tube coating; in-situ and field coating applications.

Used Exchanger Tube Repair

Curran has mastered surface prep and application methods for coating in-service exchangers, this technique is used to restore exchangers for continued service. Curran can achieve NACE 1 white metal cleanliness of in-service exchanger tubes, and its application methods satisfy holiday spark testing requirements – even in pitted tubes. A homogeneous thin film coated tube mitigates fouling in heat exchangers and prevents tube ID corrosion.

Curran Exchanger Coating Benefits

  • Reduce fouling
  • Precipitate scaling
  • Mitigate corrosion and velocity erosion
  • Eliminate routine exchanger maintenance
  • Extend useful life of exchangers
  • Reduce head pressure
  • Energy savings (support Energy Exchanger initiatives)
Curran 1000T shell & tube exchanger
Curran 1000T shell & tube exchanger

Thin Film Exchanger Coatings

Curran 1000 – Advanced two-part 100% solids epoxy coating designed for high temperature immersion service in cooling water, hydrocarbons and process streams. This coating is an organic/inorganic hybrid with superior mechanical performance; resistant in cooling water steam services to 365°F and excursions to 400°F (204°C). Applied to 8-14 mils total DFT.

Curramix 2500 – An ultra-low DFT ambient-cure coating system designed for high temperature fouling services; excellent hydrophobic & oleophobic properties, anti-coking performance, resistant to thermal cycling, and can be used in 1200°F. May be applied to heat exchanger tubes, plate & frame exchangers. Applied to 20-40 microns total DFT.

Curramix 3500 – An advanced anti-coking ceramic coating for crude and hydrocarbon fouling; excellent hydrophobic & oleophobic properties, anti-coking performance, resistant to thermal cycling, and maintains repellency to 750°F. Applied to heat exchanger tubes, plate & frame exchangers. Applied to 12 to 38 microns total DFT.

Baked Phenolic – Shop applied, bake catalyzed, suitable for all cooling water services, hydro carbons, salt solutions and solvents. Immersion resistance to 365°F; applied to 7-10 mils total DFT.

Chemours Ruby Red PFA – Shop applied, bake catalyzed fluoropolymers; superior resistance in chemicals, solvents and acids. Immersion resistant to 500°F. Applied to 5 - 8 mils DFT.

Danish Technological Institute (DTI) – Low surface energy hydrophobic coating, applied at 5 – 40 microns film thickness; Curran applied to tubular, and plate & frame exchangers in crude derived services, produced water services.

Chemours StreaMax™– Non-stick release fluoropolymer with excellent adhesion to applied surfaces and high permeation resistance. The very low friction coefficient prevents fouling of exchangers in oil production and crude refining.

Sol Gel Coatings – Polymer surface treatment; omniphobic (water and oil repellant) nanocomposite surface treatment that creates slick surface. Applied to 50 mils; water and product services to 400F.

Contact Curran International about your heat exchanger reliability and fouling challenges so we can develop a solution.