Port Geometry and Gasket Seating on a Pressure Part
Controlled gland squeeze between 15% and 25% prevents mechanical die stress while isolating the pressure port against long-term fluid leakage.
Pneumatic Decay Leak Testing
Integrity Verification
Non-destructive leak detection measures pressure drop over time in a sealed test volume charged with compressed gas. Production line quality control uses pneumatic decay leak testing to verify seal integrity in flowmeter bodies and valve housings. The procedure isolates a pressurized component and monitors pressure decay using high-resolution differential pressure transmitters.
The method ceases to function effectively when test volume thermal stabilization times are omitted prior to measurement.
Pressure Drop
Test chamber filling elevates gas temperature due to adiabatic compression. Temperature stabilization periods prevent false leak indications caused by pressure reduction from natural gas cooling.
Sensitivity Boundary
Small leaks generate minute pressure drops that demand high-resolution pressure transducers and precise temperature compensation. In pneumatic decay leak testing, background temperature fluctuations disguise true leakage rates if thermal equilibrium is not achieved before the measurement phase. The minimum detectable leak rate depends directly on test volume size, gas temperature stability, dwell time, and sensor resolution.
Large test volumes decrease pressure change sensitivity, requiring longer test cycle times to detect micro-leaks.
Quality Specification
ASTM E515 sets criteria for pressure decay testing, defining maximum permissible leak rates for industrial pressure vessels. Calibration against a certified calibrated leak orifice verifies system sensitivity before testing production batches.