CORE SERVICE OFFERINGS
TCR Arabia offers a diverse range of Heat Treatment Services including pre-heating, post-heating; stress relieving (SR), intermediate SR, normalizing, solution annealing, water quenching, tempering, step cooling and drying of the refractory material.
The experienced technicians at TCR are capable of performing heat treatment on weld joints, piping, regenerators, stripper columns, pressure vessels, boiler headers, modules, deck pipelines and structure, boiler heater tubes, and DOTHERM testing. The team is also capable of carrying out Post-weld heat treatment of carbon steel piping welds (pipe-work, headers, flange joints, valves and branches) by means of the electrical resistance method, in the form of ceramic heater pads. It can design, fabricate, calibrate and run a customized electrical furnace for clients.
Post Weld Heat Treatment (PWHT) using Electric Resistance
TCR Arabia offers post weld heat treatment by using electricity as a source of heating for stress relieving of weld joints. All TCR Arabia heat treatment services are designed to minimize downtime, improve structural integrity, and enhance effective plant life. Additionally, depending on the mobility of the required equipment many of our heating processes can be applied on-site or at your facility.
TCR Arabia has specialized personnel and equipment to carry out a wide range of heat treatment processes like post weld heat treatment of vessels, piping, spheres and fabricated spools. TCR Arabia specializes in local Post weld heat treatment of carbon steel piping welds (pipe-work, headers, flange joints, valves, and branches) by means of the electrical resistance method, in the form of ceramic heater pads.
All PWHT equipment in use by TCR Arabia is purpose built and have a valid current calibration certificate. Electric power sources are 380/415/440V 3 phase 50Hz primary supply step down transformer secondary output (heat treatment unit) giving low voltage circuits. Temperature control equipment is either manually operated through energy regulators or automatically operated using modular controls. Recording of temperature, for the electrical resistance method, or the induction heating method is by means of calibrated chart type temperature recorder. Calibration frequency of recorders will be one year.
Post Weld Heat Treatment Services (PWHT) is performed after welding/machining, to improve the chemical and mechanical properties of weldment / machined surfaces. TCR offers post-weld heat treatment by using electricity as the source of heating for stress relieving of weld joints. All TCR’s heat treatment services are designed to minimize downtime, improve structural integrity and enhance effective plant life. Additionally, depending on the mobility of the required equipment, many of TCR’s heating processes can be applied on-site or at the client’s facility.
Conceptually, PWHT covers many different potential treatments:
Stress Relieving: For steel fabrication, the most common procedure used is Stress Relieving where machining and/or welding induces stress in parts. The bigger and more complex the part, higher is the amount of stress. Stress Relieving is done by uniformly heating the fabricated equipment, a vessel or a part of the vessel to a sufficiently high temperature, but below the lower transformation temperature range. It is then subjected to thermal retardation for a sufficient time depending upon the material thickness and then finally cooled uniformly.
TCR has specialized fully-automatic programmable equipment capable of controlling Heating rate, Holding time and cooling rate as well as carrying out a wide range of heat treatment processes like post-weld heat treatment of PQR test coupons and various components. TCR has at its disposal, well-equipped tools including electrical furnace with 220 and 80 Volts panel, latest 12 point recorder with digital display, coil and pad-type heating element, oil firing systems and extremely skilled technicians. The Heat treatment equipment is supplied with a chart recorder to record up to 8 thermocouples simultaneously to meet the critical requirements of heat treatment.
Codes and Standards
ASME B31.3: Process Piping
ASME Sec IX: Welding and Brazing Qualification
AWS D10.10: Local Heat treatment of Welds in Piping and Tubing.
Strong Commitment to Safety
Reference shall be made to the Safety Plans, Task Risk Assessments and Safety Method Statement pertinent to the work being carried out and to the work location. All heating elements shall be thoroughly examined before use in order to ensure that the element wire is not exposed. Examination to be also made for broken beads in both the heater pad and the element tails. The twist-lock connection shall also be examined to ensure that the insulation is sound and that a good electrical joint is made. All cable connections shall be properly insulated. The component surface shall be free of contaminants.
Before a Heat Treatment is switched on particular attention shall be paid to the work area to ensure that there are no combustible materials present which can be affected by the heated zone, and that fire prevention/protection measures are available.
Documentation & Reporting of Test Results
Upon completion of each electrical resistance Local PWHT cycle, the Local PWHT Thermocouple Identification form shall be filled in and attached to the recorder chart. The time-temperature curves on the recorder chart shall be marked to identify the corresponding thermocouples. The Local PWHT Report Form shall be filled and handed over to the client as generic records. PWHT chart shall be signed at the start of PWHT cycle by approved PWHT technician with weld number, date, start time etc. Thermocouple identification form will be fixed on the chart after PWHT cycle.
PWHT of Pressure Vessels using Oil Firing Method
TCR Arabia has a talented crew that uses diesel fuel as the source of heating for stress relieving of pressure vessels with the sole objective of reinforcing process, component integrity, and high quality. The heat treatment specialists from TCR have all the necessary experience and equipment to develop a custom configuration as per specific processes. Our heating processes include low-Range, Mid-Range & High-Range Temperature Heating.
TCR Arabia's high-velocity burners enable excellent temperature distribution and uniformity at all times because of the intense scrubbing action. They are also able to construct temporary furnaces at client sites where internal firing is not a practical or cost-effective option.
The heat treatment operation is affected by the firing of the furnace, using one or more gas/oil high-velocity burners with a nominal rating of 1,500.000 Kcals/HR (6,000,000 Btu/HR) per burner. Each burner is connected by an armored flexible hosing to Combustion Air Fan (s), with a maximum output of 2800/Nm³ per hour via a 150mm diameter outlet, at a pressure of 700mm W.G. The burner is fitted with a (25/20) stainless steel outlet nozzle designed to clear the furnace wall adjacent to the intended opening(s), in such a way that it eliminates the possibility of any direct impingement on components.