We undertook the Penglai Cross-Sea Water Diversion Project. This project involved complex marine hydrological conditions, with strong seawater corrosion and impact. Our company's products, employing integrated internal and external welding and with a standard pipe length of 25 meters, ensured the success of the cross-sea water diversion project due to their superior resistance to alternating loads and system stability. This solved the long-standing problem of rainwater and saltwater for island residents. Our steel-plastic composite pipes also withstood the technical challenges of long-term high pressure from both inside and outside the deep sea.