Linear gate movement
The Class 300 flanged gate valve uses an outside-screw-and-yoke rising-stem mechanism. Handwheel rotation operates the threaded mechanism to move the gate linearly; it does not rotate the gate like a butterfly disc. Allow clearance for the full stem travel.
Does Class 300 mean 300 psi?
No. Class 300 is a pressure-temperature class, not a constant 300 psi working pressure or a universal PN equivalent. Use the applicable material group and design temperature, and consider the limits of the complete valve.
Material and dimensions
WCB, CF8, CF8M and CF3M are distinct material options in the published information, not simultaneous body materials. Confirm the selected grade, size, flange drilling, facing and face-to-face length against the offered drawing. A generic size range is not confirmation of every available combination.
Standards and intended duty
Design, flange dimensions, face-to-face dimensions and tests are separate requirements. API 600 and API 603 have different scopes; confirm the applicable construction and agreed references rather than claiming universal compliance. An ordinary isolation gate valve is normally fully open or closed; continuous throttling needs an appropriate design and process review.
Enquiry and technical documents
Provide fluid composition, normal and maximum pressure and temperature, flow, size, connections and operating requirements. Verify the selected data sheet, assembly drawing, material documents and agreed tests; do not transfer ratings from a different product.
