Fitness-for-purpose assessment of repaired feedwater heater
Ocena podobnosti za upotrebu zagrejača napojne vode posle popravke
Апстракт
The leakage of tube-tubesheet joint of feedwater heater on the inlet required redesign and repair by additional tube welding. The original design took into account only the sealing, and subsequently after some period leakage occurred due to tube displacement in tubesheet, caused by thermal and mechanical overload. Repair procedure included cutting out the heater header along the welded joint, preparing and welding the tubes to the tubesheet and repeated welding of the header. The header and tubesheet are made of carbon steel. Welding procedure anticipated an austenitic soft interlayer and local heat treatment for residual stress relaxation before final joining. Fitness-for-purpose assessment has been issued and models were developed by finite element analysis according to the design solution and condition after repair. The results of mechanical and thermal responses of model confirmed that repaired feedwater heater is fit for purpose.
Pricurivanje na spoju cevi i cevne place na ulazu u zagrejač vode je zahtevalo rekonstrukciju i popravku dodatnim zavarivanjem cevi. Prvobitnim projektom je u obzir uzeto samo zaptivanje i posle nekog vremena u radu je došlo do curenja zbog pomeranja cevi u cevnoj ploči, izazvanog termičkim i mehaničkim preopterećenjem. Postupak popravke je predvideo isecanje glave zagrejača po zavarenom spoju, pripremu i zavarivanje cevi za cevnu ploču, i ponovno zavarivanje glave. Glava i cevna ploča su izrađeni od ugljeničnog čelika. Postupak zavarivanja je predvideo austenitni meki sloj i lokalnu termičku obradu za otpuštanje zaostalih napona pre završnog spajanja. Ocena podobnosti za upotrebu je zahtevana i razvijeni su modeli prema projektnom rešenju i stanju posle popravke analizom konačnim elementima Rezultati mehaničkog i termičkog odgovora modela su potvrdili da je popravljeni zagrejač napojne vode podoban za upotrebu.
Кључне речи:
water heater / fitness-for-purpose / repair by welding / modeling / stress analysis / zagrejacč vode / podobnost za upotrebu / popravka zavarivanjem / modelovanje / analiza naponaИзвор:
Integritet i vek konstrukcija, 2006, 6, 3, 111-120Издавач:
- Society for Structural Integrity and Life, Institute for Material Testing
Институција/група
Tehnološko-metalurški fakultetTY - JOUR AU - Maneski, Taško AU - Sedmak, Aleksandar AU - Milović, Ljubica AU - Fertilio, Antun AU - Sedmak, Stojan PY - 2006 UR - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/985 AB - The leakage of tube-tubesheet joint of feedwater heater on the inlet required redesign and repair by additional tube welding. The original design took into account only the sealing, and subsequently after some period leakage occurred due to tube displacement in tubesheet, caused by thermal and mechanical overload. Repair procedure included cutting out the heater header along the welded joint, preparing and welding the tubes to the tubesheet and repeated welding of the header. The header and tubesheet are made of carbon steel. Welding procedure anticipated an austenitic soft interlayer and local heat treatment for residual stress relaxation before final joining. Fitness-for-purpose assessment has been issued and models were developed by finite element analysis according to the design solution and condition after repair. The results of mechanical and thermal responses of model confirmed that repaired feedwater heater is fit for purpose. AB - Pricurivanje na spoju cevi i cevne place na ulazu u zagrejač vode je zahtevalo rekonstrukciju i popravku dodatnim zavarivanjem cevi. Prvobitnim projektom je u obzir uzeto samo zaptivanje i posle nekog vremena u radu je došlo do curenja zbog pomeranja cevi u cevnoj ploči, izazvanog termičkim i mehaničkim preopterećenjem. Postupak popravke je predvideo isecanje glave zagrejača po zavarenom spoju, pripremu i zavarivanje cevi za cevnu ploču, i ponovno zavarivanje glave. Glava i cevna ploča su izrađeni od ugljeničnog čelika. Postupak zavarivanja je predvideo austenitni meki sloj i lokalnu termičku obradu za otpuštanje zaostalih napona pre završnog spajanja. Ocena podobnosti za upotrebu je zahtevana i razvijeni su modeli prema projektnom rešenju i stanju posle popravke analizom konačnim elementima Rezultati mehaničkog i termičkog odgovora modela su potvrdili da je popravljeni zagrejač napojne vode podoban za upotrebu. PB - Society for Structural Integrity and Life, Institute for Material Testing T2 - Integritet i vek konstrukcija T1 - Fitness-for-purpose assessment of repaired feedwater heater T1 - Ocena podobnosti za upotrebu zagrejača napojne vode posle popravke EP - 120 IS - 3 SP - 111 VL - 6 UR - https://hdl.handle.net/21.15107/rcub_technorep_985 ER -
@article{ author = "Maneski, Taško and Sedmak, Aleksandar and Milović, Ljubica and Fertilio, Antun and Sedmak, Stojan", year = "2006", abstract = "The leakage of tube-tubesheet joint of feedwater heater on the inlet required redesign and repair by additional tube welding. The original design took into account only the sealing, and subsequently after some period leakage occurred due to tube displacement in tubesheet, caused by thermal and mechanical overload. Repair procedure included cutting out the heater header along the welded joint, preparing and welding the tubes to the tubesheet and repeated welding of the header. The header and tubesheet are made of carbon steel. Welding procedure anticipated an austenitic soft interlayer and local heat treatment for residual stress relaxation before final joining. Fitness-for-purpose assessment has been issued and models were developed by finite element analysis according to the design solution and condition after repair. The results of mechanical and thermal responses of model confirmed that repaired feedwater heater is fit for purpose., Pricurivanje na spoju cevi i cevne place na ulazu u zagrejač vode je zahtevalo rekonstrukciju i popravku dodatnim zavarivanjem cevi. Prvobitnim projektom je u obzir uzeto samo zaptivanje i posle nekog vremena u radu je došlo do curenja zbog pomeranja cevi u cevnoj ploči, izazvanog termičkim i mehaničkim preopterećenjem. Postupak popravke je predvideo isecanje glave zagrejača po zavarenom spoju, pripremu i zavarivanje cevi za cevnu ploču, i ponovno zavarivanje glave. Glava i cevna ploča su izrađeni od ugljeničnog čelika. Postupak zavarivanja je predvideo austenitni meki sloj i lokalnu termičku obradu za otpuštanje zaostalih napona pre završnog spajanja. Ocena podobnosti za upotrebu je zahtevana i razvijeni su modeli prema projektnom rešenju i stanju posle popravke analizom konačnim elementima Rezultati mehaničkog i termičkog odgovora modela su potvrdili da je popravljeni zagrejač napojne vode podoban za upotrebu.", publisher = "Society for Structural Integrity and Life, Institute for Material Testing", journal = "Integritet i vek konstrukcija", title = "Fitness-for-purpose assessment of repaired feedwater heater, Ocena podobnosti za upotrebu zagrejača napojne vode posle popravke", pages = "120-111", number = "3", volume = "6", url = "https://hdl.handle.net/21.15107/rcub_technorep_985" }
Maneski, T., Sedmak, A., Milović, L., Fertilio, A.,& Sedmak, S.. (2006). Fitness-for-purpose assessment of repaired feedwater heater. in Integritet i vek konstrukcija Society for Structural Integrity and Life, Institute for Material Testing., 6(3), 111-120. https://hdl.handle.net/21.15107/rcub_technorep_985
Maneski T, Sedmak A, Milović L, Fertilio A, Sedmak S. Fitness-for-purpose assessment of repaired feedwater heater. in Integritet i vek konstrukcija. 2006;6(3):111-120. https://hdl.handle.net/21.15107/rcub_technorep_985 .
Maneski, Taško, Sedmak, Aleksandar, Milović, Ljubica, Fertilio, Antun, Sedmak, Stojan, "Fitness-for-purpose assessment of repaired feedwater heater" in Integritet i vek konstrukcija, 6, no. 3 (2006):111-120, https://hdl.handle.net/21.15107/rcub_technorep_985 .