Guidelines for Repair Welding of Pressure Equipment in Refinery and Chemical Plants: Part 3—Repair Welding for Specific Materials - Carbon Steel, High Tensile Steel and Cr-Mo Steel

2011 ◽  
Author(s):  
Rinzo Kayano ◽  
Masamitsu Abe ◽  
Yukio Hirai
Keyword(s):  
Carbon Steel ◽  
Pressure Vessels ◽  
Chemical Plants ◽  
Safe Operation ◽  
Gas Industry ◽  
Repair Welding ◽  
Weld Residual Stress ◽  
Natural Gas Industry ◽  
And Storage

It has been recognized that repair welding plays an important role in the long term, safe operation of pressure equipment. In 2009, The Japan Welding Society (JWES) published guidelines for repair welding of pressure equipment [1], to meet the great need for the safe operation and proper maintenance of aging plants. Pressure equipments made from carbon steel, high tensile steel and Cr-Mo steels are utilized for high pressure services. The subject equipments are pressure vessels, heat exchangers, piping, and storage tanks for petroleum, petrochemical and liquefied natural gas industry. This paper summarizes category and property of these steels and repair welding method including special attention. Especially, weld cold cracking for these steels could be prevented by controlling the repair welding and post-weld heat treatment process to reduce the hydrogen content, hardness and weld residual stress.

Guidelines for Repair Welding of Pressure Equipment in Refineries and Chemical Plants: Part 2—Repair Welding Method

2011 ◽  
Author(s):  
Keisuke Shiga ◽  
Yukio Hirai ◽  
Ogayu Yasushi
Keyword(s):  
Chemical Plant ◽  
Chemical Plants ◽  
Safe Operation ◽  
Research Committee ◽  
Repair Welding ◽  
Welding Method ◽  
Engineering Society

It has been recognized that repair welding plays an important role of in the long term, safe operation of pressure equipment. In 2009, the Japan Welding Engineering Society (JWES) published guidelines for repair welding of pressure equipment, to meet the great need for the safe operation and proper maintenance of aging plants. This paper gives brief descriptions of three types of repair welding method, “Flaw excavation and repair welding”, “Butt-welded insert plates”, and “External fillet welded patches”, which welding methods are based on Chemical Plant Welding Research Committee of JWES.

Guidelines for Repair Welding of Pressure Equipment in Refineries and Chemical Plants: Part 4—Weld Repair for Specific Materials - Stainless Steel, Clad Steel and Dissimilar Joints

2011 ◽  
Author(s):  
Tsukasa Okazaki ◽  
Rinzo Kayano ◽  
Takahisa Hoshika ◽  
Shinta Niimoto
Keyword(s):  
Stainless Steel ◽  
Chemical Plants ◽  
Safe Operation ◽  
Weld Repair ◽  
Dissimilar Joints ◽  
Weld Overlay ◽  
Repair Welding ◽  
Engineering Society ◽  
Clad Steel

It has been recognized that repair welding plays an important role in the long term, safe operation of pressure equipment. In 2009, the Japan Welding Engineering Society (JWES) published guidelines for repair welding of pressure equipment to meet the great need for the safe operation and proper maintenance of aging plants. This paper describes Part 4 of the guideline, which covers repair welding of stainless steel, clad steel, weld overlay and dissimilar joints.

Guidelines for Repair Welding of Pressure Equipment in Refineries and Chemical Plants: Part 6—Material Degradation and Repair Welding

2011 ◽  
Author(s):  
Tomoaki Kiso ◽  
Rinzo Kayano ◽  
Eiki Nagashima ◽  
Yasuhiro Hara
Keyword(s):  
Chemical Plants ◽  
Material Degradation ◽  
Safe Operation ◽  
Damage Mechanisms ◽  
Repair Welding ◽  
Engineering Society ◽  
Key Points ◽  
Damaged Materials

It has been recognized that repair welding plays an important role in the long term, safe operation of pressure equipment. In 2009, the Japan Welding Engineering Society (JWES) published guidelines for repair welding of pressure equipment, to meet the great need for the safe operation and proper maintenance of aging plants. This paper addresses the key points of repair welding for damaged materials, based on JWES’s guidelines. The various factors to be considered before implementing repair welding and typical methods of repair welding for the major damage mechanisms are summarized.

Safety Assessment of Long Term Serviced Pressure Vessels: A Case Study of Typical Refining and Chemical Plants in China

2021 ◽  
Author(s):  
Zhiyuan Han ◽  
Guoshan Xie ◽  
Haiyi Jiang ◽  
Xiaowei Li
Keyword(s):  
Pressure Vessel ◽  
Safety Assessment ◽  
Failure Modes ◽  
Pressure Vessels ◽  
Time Dependent ◽  
Chemical Plants ◽  
Safety Specification ◽  
Detailed Assessment

Abstract The safety and risk of the long term serviced pressure vessels, especially which serviced more than 20 years, has become one of the most concerned issues in refining and chemical industry and government safety supervision in China. According to the Chinese pressure vessel safety specification TSG 21-2016 “Supervision Regulation on Safety Technology for Stationary Pressure Vessel”, if necessary, safety assessment should be performed for the pressure vessel which reaches the design service life or exceeds 20 years without a definite design life. However, the safety and risk conditions of most pressure vessels have little changes after long term serviced because their failure modes are time-independent. Thus the key problem is to identify the devices with the time-dependent failure modes and assess them based on the failure modes. This study provided a case study on 16 typical refining and chemical plants including 1870 pressure vessels serviced more than 20 years. The quantitative risk and damage mechanisms were calculated based on API 581, the time-dependent and time-independent failure modes were identified, and the typical pressure vessels were assessed based on API 579. Taking the high pressure hydrogenation plant as an example, this study gave the detailed assessment results and conclusions. The results and suggestions in this study are essential for the safety supervision and extending life of long term serviced pressure vessels in China.

Repair Weldability at Overlay/Base Metal Interface of Petroleum Pressure Vessel

2008 ◽  
Author(s):  
Rinzo Kayano ◽  
Hiroaki Mori ◽  
Kazutoshi Nishimoto
Keyword(s):  
High Temperature ◽  
Hydrogen Embrittlement ◽  
Hydrogen Content ◽  
Welding Process ◽  
Pressure Vessels ◽  
Cold Cracking ◽  
Diffusible Hydrogen ◽  
Repair Welding ◽  
Crack Susceptibility

In order to extend the life of petroleum pressure vessels operated in long term, it is needed to establish the reliable repair welding technique. Weld cold cracking sometimes occurred in long-term operated petroleum pressure vessels due to hydrogen embrittlement by thermal stress and diffusible hydrogen after repair welding. The cracking was caused by the hydrogen concentration at the base meal of 2.25Cr-1Mo steel/overlaying metal of austenitic stainless steels interface during the service with high temperature and hydrogen partial pressure. The tendency was accelerated by carbide precipitation at the interface due to the post weld heat treatment (PWHT) and the operation with high temperature. That is, the crack susceptibility at the interface became markedly higher owing to the hydrogen embrittlement with metallurgical degradation by thermal embrittlement. To make clear the effect of weld thermal cycles during repair welding on the hydrogen content and weld cold cracking at the interface in the structural material of petroleum pressure vessels, the crack susceptibility was estimated by y-groove weld cracking test with varying overlay thickness and hydrogen exposure conditions. In addition, the hydrogen distribution in the material was calculated by the theoretical analysis using the diffusion equation based on activity. The crack susceptibility was raised with increase in the hydrogen content at the interface. It was concluded that the cracking could be prevented by controlling the repair welding process to reduce the hydrogen content at the interface.

Weld Repair for Pressure Vessels Made From Cr-Mo Steels

2010 ◽  
Author(s):  
Rinzo Kayano ◽  
Eiichi Yamamoto ◽  
Takayasu Tahara
Keyword(s):  
Temper Embrittlement ◽  
Welding Process ◽  
Pressure Vessels ◽  
Research Committee ◽  
Weld Repair ◽  
Repair Welding ◽  
Term Operation ◽  
Repair Procedure ◽  
Past Experiences

Pressure vessels made from Cr-Mo steels are utilized for high temperature and high pressure services including hot hydrogen services. After long term operation, there are several past experiences of damages and/or degradation of materials such as temper embrittlement, creep embrittlement, hydrogen attack and hydrogen embrittlement. This paper summarizes typical damages/degradation and examples of weld repairs including special attention to development of weld repair procedure. The subject equipments are heavy wall petroleum pressure vessels made from Cr-Mo steel with austenitic stainless steel overlay cladding. Cracking could be prevented by controlling the repair welding process to reduce the hydrogen content at the interface. After repair welding, adequate post weld heat treatment (PWHT) has to be executed. Recently, repair welding has become an important aspect as part of post construction codes for pressure equipment to keep safe and long term continuous operation of the process plants because many of the plants have been operated for more than thirty years in Japan. Responding to the needs of petroleum and chemical industries, The Chemical Plant Welding Research Committee (CPWRC) of The Japan Welding Engineering Society (JWES) established the Pressure Equipment Repair Welding Subcommittee (PERW S/C) [1]. The S/C has developed optimum repair welding methods and procedures in the guideline on November 2009, with reference to the above investigation results. This paper also introduces the repair welding guideline for the pressure vessels made from Cr-Mo steels.

Guideline for Repair Welding of Pressure Equipment in Refineries and Chemical Plants: Part 5—Repair Welding for Specific Materials - Heat Resistance Alloy and Non-Ferrous Metals

2011 ◽  
Author(s):  
Hirohisa Watanabe ◽  
Keisuke Shiga ◽  
Atsushi Ohno
Keyword(s):  
Heat Resistance ◽  
Chemical Plants ◽  
Repair Welding ◽  
Engineering Society ◽  
Ferrous Metals ◽  
Resistance Alloy ◽  
Nickel Copper ◽  
Key Points ◽  
Non Ferrous Metals

It has been recognized that repair welding takes an important role in the long term, safe operation of pressure equipment. Responding to the needs in petroleum and chemical industries, the Japan Welding Engineering Society (JWES) published Guideline for repair welding of pressure equipment at 2009. This paper describes the key points of repair welding for heat resistance alloy and non-ferrous metals such as Nickel, Copper, Titanium and their alloys, based on JWES’s guidelines. Before implementing repair welding, it is important to understand the features of damaged materials, because these materials have been used at severe environment in plants.

Effect of Hydrogen Concentration at Overlay / Base Metal Interface on Repair Weldability of Petroleum Pressure Vessel

2008 ◽  
Vol 580-582 ◽  
pp. 5-8
Author(s):  
Hiroaki Mori ◽  
Kazutoshi Nishimoto ◽  
Rinzo Kayano
Keyword(s):  
Base Metal ◽  
Hydrogen Content ◽  
Welding Process ◽  
Austenitic Stainless Steels ◽  
Pressure Vessels ◽  
Hydrogen Distribution ◽  
Repair Welding ◽  
Hydrogen Exposure ◽  
Crack Susceptibility

In order to extend the life of petroleum pressure vessels operated in long term, it is demanded to establish the repair welding technique. To make clear the effect of weld thermal cycles during repair welding on the hydrogen content and weld cold cracking at the base metal of 2.25Cr- 1Mo steel / overlaying metal of austenitic stainless steels interface in the structural material of petroleum pressure vessels, the crack susceptibility was estimated by y-groove weld cracking test and repair welding test with varying overlay thickness and hydrogen exposure conditions. In addition, the hydrogen distribution in the material was calculated by the theoretical analysis using the diffusion equation based on activity. The crack susceptibility was raised with increase in the hydrogen content at the interface. It was concluded that the cracking could be prevented by controlling the repair welding process to reduce the hydrogen content at the interface.

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