Technical requirement
1. The internal and external surfaces shall be free of casting defects;
2. Brush antirust paint on the thread and assembly sealing surface;
3. The water pressure of the case is 2.5 MPa, and there is no leakage within 30 minutes;
4. The acute angle shall be rounded, and the thread shall be chamfered to the bottom of the first tooth diameter;
5. The surface is treated by hot spraying with blue plastic powder, with a thickness of (0.15~0.25) m, firmly and evenly attached without sagging;
6. Undeclared dimensional tolerance shall comply with GB/T1804-m,
Undeclared line position tolerance shall comply with GB/T1184-k.