The document summarizes a strength calculation for 4 socket head screws (M4x16 8.8) used to secure a circulator pump. It calculates that with a maximum pressure of 6 bar and surface area of 0.002025 m^2, the maximum force on the bolts would be 11,451 N or 2.863 kN. This force would be divided evenly among the 4 bolts, coming out to around 3-5 kN of tension per bolt, which is within specifications according to tension tables for M4 bolts. Therefore, the document determines that the bolts chosen were suitable for the application.

1. Bolts in circulator pumpStrength calculation

2. Used bolts: 4 socket head screws M4x16 8.8

3. Strength class bolts: 8.8Minimum tensile strength: 800 N/mm²Rack limit: 640 N/mm²

5. Maximum pressure (p) in the circulator pump: 6 bar = 6 x 105 PaSurface (A) = r2 x π = 0,04502 x π = 0,002025 m2Fb = p x A = 6 x 105 x 0,04502 x π = 3817 NFVmax= 3 x Fb = 3 x 3817 = 11451 NDivided over 4 bolts11451 / 4= 2863N =2,863 kNThe tension of a M4 bolt will be around 3-5 kN (see tension table next slide)According to the calculations the right bolts were chosen(I had no information about the friction coefficient)r = 0,0450 m

6. Tension table(I could not find a tension table with bolts smaller than a M5, so I had to estimate the tension for a M4)M4