Leak Testing (Hydro/Pneumatic/Helium)

A: Accepting the line list value risks overstressing low-MAWP spools if the number was copied from a different service. Using the higher pressure can silently exceed flange or valve test ratings and create latent damage. Defaulting to code minimum ignores project-specific design margins and contractual requirements. Raising an NCR forces reconciliation of MAWP, class rating, and test philosophy before pressurization energy is introduced.

A: A pneumatic soap test struggles to detect the sub-micron leaks that drive SIL spurious trips. A hydrotest introduces water into dead legs and risks long-term corrosion and freezing issues. Skipping testing assumes assembly integrity that field make-up doesn't guarantee. Helium testing aligns with dry service, high pressure, and low allowable leak rates without adding stored energy.

A: Blind installation should already be locked down earlier to avoid last-minute line breaks. Chloride checks matter but don't prevent overpressure during the ramp. Uncalibrated or mismatched gauges are how you exceed allowable stress without realizing it. ITP sign-off is administrative and doesn't control real-time pressurization risk.

A: Failing automatically ignores basic gas behavior and leads to unnecessary rework. Assuming a leak without correction misreads thermodynamics as mechanical failure. Increasing pressure adds stored energy and can breach test limits. Temperature correction aligns observed decay with ideal gas effects before calling a leak.