Trunnion Ball Valve Seat Seal Force

Metal seat sealing pressure design for fixed-shaft ball valves per Valve Design Manual criteria. Verify qMF, q and allowable sealing pressure.

Open Calculator →

Core Formula:
q_MF ≤ q ≤ [q]

Where:
• q_MF = necessary seal pressure (MPa), minimum pressure to achieve sealing
• q = actual seat sealing pressure (MPa), = F_N / A_seat
• [q] = allowable sealing pressure (MPa), material-dependent limit
• F_N = normal force on seat from medium pressure + spring
• A_seat = effective seat contact area

Judgment: q must be between qMF and [q] for reliable sealing → PASS

Why This Calculator

Seal Pressure Triad

Three-point verification: minimum needed qMF, actual q, and allowable [q].

Medium-Driven Force

Normal force calculated from operating pressure acting on seat annulus area.

Material Allowable

[q] depends on seat/ball material pair per Valve Design Manual tables.

Auto Pass/Fail

Instant judgment: qMF ≤ q ≤ [q] checked automatically.

Spring Preload

Includes spring force contribution to ensure seating at low pressure.

Part of Design Suite

One of 12 modules in the complete Ball Valve Design Calculation suite.

How It Works

Enter Parameters

Input operating pressure, seat geometry dimensions, material allowable sealing pressure.

Compute Seat Forces

Calculate normal force FN from medium pressure and spring preload on seat.

Calculate Pressures

Compute necessary qMF, actual seat pressure q from FN/area, and verify against [q].

Verify Seal Integrity

Check qMF ≤ q ≤ [q] condition; pass/fail displayed for seal reliability.

Who Is It For

Valve Design Engineers | Seal Specialists | Quality Inspectors | R&D Engineers

Key Highlights

Valve Design ManualTriple CheckAuto JudgmentMaterial-Based

Ready to Calculate?

Enter your design parameters and get instant verification results.

Open Calculator →