Certification and inspection documents

Construction and description

A gate valve isolates a pipeline by raising or lowering its gate and is generally used fully open or fully closed. In the open position the gate clears the main passage. Prolonged partial opening can cause localized erosion and vibration; continuous flow regulation requires a valve designed for that duty.

The gate-to-seat arrangement determines isolation behavior. Define gate geometry, sealing-surface materials and solids exposure. Installation should provide clearance for stem travel, handwheel operation and bonnet maintenance.

Match the operator to the valve load and site operating method. Manual operation needs accessible clearance. Frequent cycling or remote control also calls for assessment of output capability, duty and position feedback.

Service conditions

Cryogenic fluids cause contraction and alter seal and operating conditions. Review low-temperature material behavior, stem-seal temperature management and orientation. System design must address expansion and pressure accumulation wherever liquid can become trapped.