Gate Valve Basics

A gate valve can be used for starting and stopping flow but they cannot regulate the level of flow. They are in fact

designed to isolate or connect fluids, however. A partial flow is not something ideally managed through a gate valve, as this

can damage the gate and introduce vibration.

Their name comes from how they operate, with a gate sliding in between the seats of the valve at a right angle to the fluid

flow. The gate can be shaped like a wedge, knife, or parallel.

Physically, gate valves are higher than globe valves when fully opened, but have a smaller face to face length. The gate being

moved up or down is easy to visually acknowledge as the valves operate with either a rising stem or a non‐rising stem.

Gate valves possess very little fluid flow resistance when fully open, and as the gate will fully retract in its bonnet, pressure

drops are fairly low, accommodating frequent opening and closing action. That being said, gate valves are more prone to

seat and disk wear than globe valves.

One of the big differences between a gate valve and a globe valve: a gate valve can be installed in various directions while a

globe valve only goes in one direction.

A gate valve should only be installed where the valve can be fully opened and shut, and should not be over tightened as

there is a risk to distorting the gate.

Globe Valve Basics

Globe valves can be used to start, stop, and regulate flow. Their name comes from the shape of the valve body itself. In

operation, a cone‐shaped plug moves in and out of the flow of fluid. The flow is controlled by how far away the plug is from

its seat. Operators should be careful not to turn the valve shaft too far, as it can damage the seating.

They offer more resistance to fluid flow, and have a high‐pressure drop even when the valve is fully open.

Globe valves generally seal better than gate valves and last longer. They are more expensive than similarly sized gate valves,

but may be worth the extra expense in situations where throttling is needed.