Titanium heat exchanger tube bundle failure 5 real cases: 90% of the factory has been in the move

Published by Engineering Team, Shaanxi Qianyi Tuoda Technology Co., Ltd on 2026-08-01

Titanium heat exchangers are often considered to have a long stable life cycle, But in actual chemistry,, Seawater operating conditions, A lot of equipment will have bundle failure within 1-3 years.The failure of tube bundle mostly stems from improper material selection, process selection or field use control.Shaanxi Qianyi Tuoda deeply cultivated titanium non-standard products rooted in Baoji Titanium Valley for 12 years, This article avoids boring theory, Share 5 real tube bundle failure cases, Each case includes equipment loss, Failure causes and corrective action plan.After reading this article, it will help enterprises avoid risks and reduce high maintenance investment.

Core conclusion: The failure of titanium heat exchanger tube bundle has five main causes, which are expansion after expansion, delamination of composite tube sheet,titanium pipepitting perforation, stress corrosion of weld, vibration fracture of tube bundle.The following is combined with the actual case interpretation one by one, enterprises can carry out equipment self-inspection against the case.

Case 1: expansion after expansion, 600,000 heat exchangers damaged in 3 months Incident scenario: wet chlorine cooler of a 300,000 ton/year caustic soda plant, DN500, PN1.6MPa equipment, TA10titanium pipeBeam, a total of 280.The contract stipulates that the hydraulic expansion pressure range is 80-120MPa. Field conditions: In order to improve the assembly effect, the field operators will adjust the expansion pressure to 150MPa.After 3 months of operation,titanium pipeThe outer diameter expanded by 1.5%, and microcracks were found at the connection between tube bundle and tubesheet. losses, The whole heat exchanger can no longer be put into service, Parking repair cycle 14 days, Supporting output value is greatly affected, Need to be replaced entirelytitanium pipeBundle. Source of failure: expansion leads to expansiontitanium pipeMicro-cracks.There is a boundary in the ductility of titanium materials, and microcracks are easy to occur when the expansion ratio exceeds 2.0%.The micro-cracks will continue to propagate in 1 - 3 months until perforation in the medium containing chloride ions. Rectification plan: replace with new onetitanium pipeBeam, strictly follow the 80-120MPa expansion pressure curve, the holding for 10 minutes.Add expansion pressure recorder, keep the processing data of each heat exchange tube, and realize process traceability.After rectification, the equipment has been running stably for 24 months without abnormal problems. Pit avoidance points: expansion pressure control within 120MPa, expansion rate is not higher than 2.0%.Over-expansion is a hidden risk and micro-cracks can take months to expose.

Case 2: Delamination of composite tubesheet, 800,000 tubesheets of PTA plant scrapped Incident scene: oxidation reactor condenser of a 500,000 ton/year PTA unit, DN600, PN1.0MPa, titanium steel composite tube plate, drawing design multilayer titanium material thickness of 2mm, base steel 8 mm. Field conditions: the supplier is to reduce the cost, delivery titanium cladding only 1.5mm.18 months after commissioning, Delamination occurs in the tubesheet and bundle junction area, Acetic acid medium containing bromide ions penetrates into base layer, Causing corrosion and perforation. losses, The whole set of composite tube sheets failed and scrapped, 21 days of repair, Damage to output value, The tube bundle and tubesheet assemblies need to be replaced simultaneously. Failure source: Delamination due to insufficient multilayer thickness.2mm is the minimum material standard for multiple layers under this working condition, 1.5mm plate in bromine-ion-containing condition, Delamination occurs with a high probability in 1 to 2 years.Once delamination occurs, the medium penetrates into the substrate and the corrosion rate increases dramatically. rectification plan, Replacement of explosion welded composite tubesheet with cladding thickness of 3mm, Perform 100% UT flaw detection, The contract specifies the tolerance of multilayer thickness ±0.2mm.Stable operation for 18 months after rectification. Pit avoidance points, The thickness of the titanium clad layer of the clad tube plate shall not be less than 2mm, 100% UT test must be done, The bonding area of plates shall not be less than 98%, Delamination defects are not allowed.

Case 3:titanium pipePitting holes, seawater desalination million units damaged Incident scenario: a 100,000 tons/day seawater desalination project, 12 TA2Titanium PlateType heat exchanger runs in series with plate thickness of 0.6mm.The medium is seawater, the chloride ion content is 19000ppm, and the operating temperature range is 25-40℃. Field conditions: supplier compression cost, selection of annealed TA2 plate, hardness 110-130HV;Seawater scour conditions require higher hardness sheets.After 18 months of operation, pitting and perforation appeared on the plates. Loss situation: the whole set of plate heat exchanger is scrapped, and the project capacity is affected due to 30 days of shutdown and repair. Failure source: Seawater conditions require hard TA2 sheets.Annealed TA2 hardness is low, Weak erosion resistance, High chloride ion seawater environment, Insufficient hardness will cause pitting and perforation within 1 to 2 years. rectification plan, Replace HV150-180 hard TA2 plate, Check hardness retest report synchronously when entering factory.Stable operation for 24 months after rectification. Key points for pit avoidance: HV≥150 hard state TA2 shall be selected under seawater condition;Annealed plate suitable for dilute acid environment, not suitable for high chloride ion seawater conditions.

case 4, weld stress corrosion, Two million equipment in chlor-alkali plant fails in one year incident scene, Evaporator of a 600,000 ton/year caustic soda planttitanium pipebundle collocationtitanium pipePlate butt weld, medium 80% sodium hydroxide, working temperature 320℃. Field conditions: the supplier compressed the construction period, and did not carry out vacuum annealing after welding.The stress corrosion cracking occurred in the weld after 1 year operation. losses, Complete evaporator failure, 45 days of repair, resulting in a large loss of output value, The overall replacement cost of equipment is relatively high. Failure source: Titanium welds require vacuum annealing.The residual stress of unannealed weld is high, and stress corrosion cracking is easy to occur within one year under high temperature and concentrated alkali conditions.Recommended annealing process: 550-600℃ for 1-2 hours, this process can not be omitted. Rectification plan: replace the whole set of tube bundle, strictly carry out vacuum annealing after welding.The supplier submits furnace temperature curve records synchronously, heat preservation at 550-600 DEG C for 2 hour, Vacuum ≤10 ²Pa.Stable operation for 24 months after rectification. Pit avoidance points: titanium welds must be vacuum annealed.During equipment acceptance, furnace temperature curve and vacuum degree record shall be verified, and incomplete data shall not be signed.

Case 5: Tube bundle vibration fracture, marine equipment 500,000 heat exchanger 6 months damage Incident scenario: a marine equipment project, DN400, PN2.5MPatitanium pipeBundle heat exchanger, medium seawater, temperature 60-120℃, total length of bundle 4m. Site conditions: supplier simplified materials and did not install baffles according to drawings.After 6 months of operation, the titanium tube bundle cracked due to vibration fatigue. Loss scenarios: complete heat exchanger scrap, offshore platform shutdown, resulting in additional production losses. Failure source: Long bundle must be supported by baffle.Titanium tubes longer than 2m, Without baffle support, Fluid-induced tube bundle vibration, When the natural frequency of the bundle is lower than the fluid excitation frequency, fatigue fracture will occur, It is a hidden danger of equipment that is not easy to detect. rectification plan, titanium baffle, Baffle spacing is controlled between 500 and 800mm, Simultaneously complete the natural frequency check calculation of the bundle.Stable operation for 18 months after rectification. Pit avoidance points: titanium pipe length greater than 2m, must be equipped with baffles, spacing to maintain 500-800mm;Visual verification is performed at equipment acceptance.

Verification means and red line requirements corresponding to the five failure causes, expansion after expansion, Monitoring by pressure recorder, The red line is pressure ≤120MPa, Expansion rate ≤2.0%composite tube plate delamination, Perform 100% UT flaw detection, The red line is multilayer thickness ≥2mm, Plate bonding area ≥98%Titanium pipe pitting, re-test with hardness tester on site, red line HV≥150 under seawater condition;weld stress corrosion, Verify furnace temperature curve and vacuum record, The red line is 550-600℃ for 2 hours vacuum annealingTube bundle vibration, check baffle assembly and frequency recheck, red line is that baffle must be installed when tube length is more than 2m.

Located in Baoji Titanium Valley, Shaanxi Qianyi Tuoda, Has 12 years of titanium non-standard processing experience, Three free technical services are available to customers.first, Free fault diagnosis, You submit failure site photos, medium working condition parameter, Engineer 30 minutes output diagnostic reference planSecond, free material selection, assist in determining equipment structure, material selection, expansion process and annealing scheme;Third, on-site repair technical support, Baoji surrounding areas can be quickly arrived, field projects within 24 hours response. Tel: 15909236031 / 0917-3557966| Official website:http://www.sxqytd.com/

written in the end These five types of failure hidden dangers of titanium heat exchanger tube bundles, A lot of it comes from early technology., Omission of material selection details, It could cause damage to the entire facility.After reading this article, risk self-examination can be carried out on existing heat exchange equipment against cases to avoid repeated occurrence of similar failures. To learn more about titanium heat exchangers, you can view the detailed explanation of titanium heat exchanger 4 types:

http://www.sxqytd.com/index.php/new/index/id/168.html;Key points of material selection for heat exchanger offshore project:http://www.sxqytd.com/index.php/new/index/id/169.html;Heat exchanger arrival acceptance specification:http://www.sxqytd.com/index.php/new/index/id/177.html;There is also a three-step purchasing decision card on the website, Procurement of technical dry goods such as pit avoidance guides, Convenient for chemical equipment procurement and engineering technicians to consult.

disclaimer, the proces parameters herein, Case Loss Description, Technical advice for technical reference only, Does not constitute a technical commitment or commercial offer.Shaanxi Qianyi Tuoda Technology Co., Ltd. reserves the right of final interpretation of this article.Technical consultation: 15909236031 / 0917-3557966.