Pipe manufacturer Welspun Gujarat Stahl Rohren will invest Rs 400 crore to set up a new plant and expand the existing facilities in Gujarat.The company will set up a new facility in Anjar, Gujarat, which will produce 300,000 tonne of pipes. The company will invest Rs 298 crore on this. The company is also planning to invest Rs 100 crore to increase its capacity, from 400,000 tonne to 550,000 tonne, at its H-saw plant in Anjar, said BK Goenka, MD, Welspun-Gujarat Stahl Rohren here today.The company's overall capacity will increase from 1.4 million tonne to 1.7 million tonne after the capacity expansion.The company's current orderbook stands at Rs 5,530 crore which will be completed in the next 18 months, Goenka said.The company also bagged a order of Rs 1835 crore from Transcanada for the supply of pipes, he said. ''We are expecting a market of $5 billion of pipes in the next five years,'' he said.