Full-bore vs reduced-bore ball valves: what is the difference
Ball valves come in full-bore and reduced-bore versions. The difference is the diameter of the ball port, which affects pressure loss, pigging, weight and price.
TAZ Engineering Team · · 5 min
What full bore means
In a full-bore valve the port is roughly equal to the pipe bore, so flow behaves as in straight pipe. A reduced-bore valve has a port one or two sizes smaller, for example a DN 100 valve with about a DN 80 port.
When full bore is needed
Transmission gas and oil pipelines that are pigged, lines where minimum head loss matters, and viscous or solids-laden media. Full-bore valves are the norm on pipelines.
When reduced bore is enough
Process and distribution lines where valve loss is small relative to the system and pigging is not planned. Reduced-bore valves are lighter and cheaper, especially in large sizes.
What to specify
State port type, DN, PN, medium, end connection and installation (above ground or buried). TAZ makes full-bore flanged ball valves.
Checklist
- port type
- DN and PN
- medium
- pigging
- allowable loss
- end connection
- installation type