Abstract: This article analyzes in detail the equal area reinforcement calculation methods stipulated in GB 50251, GB 50253 and GB 50316 for extruded tees, and compares the similarities and differences among the calculation formulas in the three standards. Taking X80 steel DN1200×DN1200×DN1000 and DN1200×DN1200×DN900 tees for example, this article performs strength calculation under a design pressure of 12MPa and a regional grade coefficient of 0.5. The results show that the reinforcement area required calculated by GB 50316 is greater than that calculated by GB 50251 and GB 50253, and the reinforcement area available calculated by GB 50316 is less than that calculated by GB 50251 and GB 50253

Key words: Equal area reinforcement, Strength calculation, Reinforcement area required, Reinforcement area available