STP&I Public Company Limited engages in the fabrication of steel works, and manufacture and sale of boilers and pressure vessels in Thailand, Japan, Spain, and internationally. It offers steel structures for airports, exhibition halls, and high-rise buildings; industrial plants, such as factories, automobile plants, and steel mills; power plants, including boiler structures and turbine buildings, as well as for equipment support structures; petrochemical plants comprising refineries, and gas separation and aromatic plants; and bridges consisting of built-in cable anchor structural decks, main structures, decking for cable stay bridges, flyovers, and pipe bridges jetties. The company provides piping pre-fabrication and erection services for various industrial plants, such as power plants, oil refineries, petrochemical plants, offshore process plants, etc., as well as produces offshore and onshore modules. In addition, it offers engineering services in the design of steel-to-steel connection, as well as shop and erection drawing services. Further, the company provides fabrication services, such as cutting/rolling/drilling, assembly and welding, inspection, blasting and painting, and packing and delivery; and plant and module construction, as well as construction support services. Additionally, it manufactures, sells, and rents construction equipment; produces and distributes electricity generated from waste products; and offers municipal solid waste management, property development, and logistics services; rents land, office buildings, and warehouses. The company was formerly known as Sino-Thai Pressure Vessel & Iron Works and changed its name to STP&I Public Company Limited in 1995. The company was founded in 1975 and is headquartered in Bangkok, Thailand.