Blind Plate Thickness

Formula overview

Consistent units: P (MPa), d and t (mm), S (MPa).

t = d · sqrt(3P / (16 · S · E)) + c, the flat circular blank rule (ASME B31.3 / B16.5), where d is the gasket reaction diameter.

Worked example

Example: P = 2 MPa, d = 200 mm, S = 138 MPa, E = 1, c = 1.5 mm
t = 200 × sqrt(3 × 2 / (16 × 138 × 1)) + 1.5
t = 200 × sqrt(6 / 2208) + 1.5 = 200 × 0.0521 + 1.5 ≈ 10.4 + 1.5 = 11.9 mm.

Common mistakes

• Using the bolt-circle diameter instead of the gasket reaction diameter for d.
• Forgetting to add the corrosion allowance.
• Ignoring extra thickness needed for the groove of a spectacle blind.

FAQ