Our orbital welding systems have long been used in the fossil fuel power generation industry. Pipe and tube welding in the electric power generation industry has greatly influenced the development of automated orbital pipe welding. A common consideration at power plants is that welds must be made in areas with limited space – tight axial and radial clearance for both initial construction and subsequent maintenance. Magnatech's engineering staff has met these challenges with compact weld heads for multipass welding – capable of operation in the rugged environment of a power plant during a maintenance outage.
Magnatech has proven solutions for component fabrication, construction, and power plant maintenance ranging from small diameter boiler tube welding to heavy wall diameter headers. We provide technical specialists for field training at the fab shop or job site.
Bharat Heavy Electrical Ltd. (BHEL) is an integrated power plant equipment manufacturer. 75% of the total power generated in India is produced by equipment from BHEL. The Trichy plant makes thousands of welds yearly on superheater, reheat and economizer tubular coil assemblies, (typical size range 25 - 75 mm OD, W.T. 4-12 mm). The tubing is bent into serpentine coils, and welds to join coils must be made with tight radial clearances between tubes. All welds must be made to ASME B31.1 code and 100% radiographic inspection is required. The combination of restricted welder access and high quality caused BHEL to investigate mechanized welding.
BHEL purchased Magnatech D-Heads to weld in the restricted spacing.
Today BHEL has twelve systems in continuous operation.
A contractor, Slattery Skanska, had to weld 40,000 linear feet of 2.5" - 42" OD, up to 2" wall P-22 and P-91 pipe. Unit 40 was a new 250 mw combined cycle plant. Work was done in an exposed location during winter. P-91 requires a 450 - 500°F (230 - 260°C) preheat, significantly impacting manual welding productivity. Location: Ravenswood Unit 40 Power Plant, Long Island City, NY.
Slattery Skanska used the Pipeliner II FCAW system which can deposit 7 lbs/hr of metal - 14 times higher than conventional manual stick (SMAW), with negligible repair rates. Productivity was further improved by allowing the welder to operate the equipment at a comfortable distance from the hot pipe.
George Ryder, Welding Superintendent, "You really have been a great help to Skanska and we appreciate all your support. It's a pleasure to deal with such a great company."
APComPower (Alstom) was awarded a contract to repair and refurbish a reheater at the Mt. Storm Power Station, involving welding old tube material to new, with tight clearances between boiler tubes. Mt. Storm is the largest coal-fired plant managed by Dominion and generates 1,600 MW.
The low profile D-Head made the multipass 2G welds, easily handling the tight radial clearance. All welds met radiographic inspection.