Pressure testing during commissioning verifies seat sealing integrity, stem seal effectiveness, body joint sealing, and structural integrity before introducing LNG, typically conducted with ambient temperature nitrogen or air while the valve is still at ambient conditions, then repeated at cryogenic temperatures during facility cool-down and initial LNG introduction to verify that the... https://globalsealstech.com/product-category/oil-gas-seals/api-6d-ball-valve-and-lng-seals/