Cryogenic Assembly and Inspection Scope

This production record documents the internal preparation and assembly of a 6-inch Class 300 F316 top-entry cryogenic ball valve for LNG service. Final configuration and acceptance criteria remain governed by the approved drawing, purchase specification, inspection and test plan, and project-specific cryogenic test procedure.

Items confirmed during assembly

• Body, cover, ball, stem and seat component identification against the production traveller and material records.
• Top-entry body cavity, ball surface, seat pockets and accessible sealing surfaces before final closure.
• Ball, stem and seat alignment, component fit, operating movement and internal positioning.
• Extended bonnet orientation, packing arrangement, bolting, flange protection, marking and preservation requirements.
• Cleanliness controls appropriate for oxygen-free LNG and low-temperature service requirements specified by the purchase order.

Cryogenic verification and records

Liquid nitrogen (LN₂) at −196°C is identified as the low-temperature verification medium. LNG normally operates at approximately −162°C; the approved procedure should define cooling rate, stabilization time, pressure stages, leakage acceptance criteria, measurement points and post-test inspection requirements.

Documents to request before shipment

Depending on the purchase order, the final document package may include material certificates, dimensional records, applicable NDE reports, pressure-test records, cryogenic test procedure and report, seat-leakage results, functional checks, nameplate details, preservation records and final packing photographs.

Project release basis

Project release should reference the approved drawing, bill of materials, inspection and test plan, pressure and cryogenic test procedures, and traceability records. Trim, seat design, leakage class, fire-safe or antistatic requirements, NDE extent and shipping preservation remain order-specific until confirmed in the purchase order and approved manufacturing documents.