Globe and gate valves look alike from the outside – both have a handwheel, a rising stem and a bonnet – yet they do very different jobs. Choosing the wrong one is a common cause of seat damage, poor control and wasted pumping energy.
The short answer
Side-by-side comparison
| Globe valve | Gate valve | |
|---|---|---|
| Primary duty | Throttling, regulating, frequent on/off | Isolation – fully open or fully closed |
| Flow path | Flow turns through the body and passes the seat | Straight through, unobstructed when open |
| Pressure drop (open) | Higher | Very low |
| Throttling ability | Good – flow changes gradually with lift | Poor – wedge and seats erode if throttled |
| Stroke | Short (disc lifts a fraction of the bore) | Long (wedge lifts the full bore) |
| Shut-off | Tight; disc closes squarely onto the seat | Tight; wedge seals on both seats |
| Flow direction | Usually marked; one preferred direction | Usually bi-directional |
| Typical uses | Steam control, bypasses, drains, dosing | Main line isolation, pump suction/discharge |
| Controtek standards | BS 1873 / DIN 2401; API 602 forged | API 600 / API 6D / BS 1414; API 602 forged |
Why gate valves should not throttle
When a gate valve is partly open, the fluid squeezes through a crescent-shaped gap under the wedge at high velocity. That jet wears the wedge and seat edges and can make the wedge vibrate. Within a short time the valve no longer seals. A globe valve is designed for this condition: the seat and disc are sized and hardened for it, and options such as a parabolic disc spread the flow change over more of the stroke.
Why not use globe valves everywhere?
Because of pressure drop. On a long, large-bore line that is always open, the extra resistance of a globe valve costs pumping energy every hour the plant runs. A full-bore gate valve avoids that loss. Large globe valves are also heavier and need more force to close against line pressure.
Where both appear together
A classic arrangement is a control valve station: gate valves isolate the control valve for maintenance, while a globe valve on the bypass lets operators regulate flow manually when the control valve is out of service.
Choosing the material and size
Both valve types are made by Controtek in carbon steel, alloy steel, stainless steel, duplex and super duplex. For small-bore lines up to 50NB, forged versions of both to API 602 are standard – see forged steel valves. Explore the full globe valve range or send us your line list for a recommendation.
