Differences between Gate Valves and Globe Valves

Valves Selection: Differences between Gate Valves and Globe Valves

In pipeline engineering, gate valves and globe valves are almost the two most frequently used types of valves. Many people confuse them, thinking that "they can all be turned on and off", but after using them incorrectly, either the pressure drop is too large and energy is wasted, or the system is unstable due to inaccurate adjustment. Today, we will thoroughly compare these two types of valves from structure to scenario, all of which are practical and useful in engineering.

Comparison of Structure between Gate Valves and Globe Valves

The most obvious difference between the two kinds of valves is their appearance and internal structure.

The structure of gate valves is relatively complex, mainly composed of valve body, valve cover, valve stem, gate (wedge-shaped or parallel), and valve seat. The gate rises and falls perpendicular to the direction of medium flow, and when fully opened, the valve passage is almost straight through, like a pipe with a plate inserted in the middle. There are two types of gate valves: the stem (with the valve stem exposed and visible during lifting and lowering) and the concealed stem (with the valve stem inside the valve body). The exposed stem requires higher installation space.

The structure of the globe valve is simpler and more intuitive: the valve body is spherical or Z-shaped, with valve discs (disc-shaped or conical), valve seats, and valve stems inside. The direction of valve disc movement is parallel to the direction of medium flow. The internal flow channel of the valve body is S-shaped or Z-shaped, and the medium must bend to pass through.

Differences of the appearance size (compared with the same caliber):

Gate valves: Short in length and high in height (especially for rising stem type), sufficient top space should be left during installation.

Globe valves: long in length, short in height, with greater horizontal space requirements.

Differences in Working Principles and Operating Modes of Globe Valves and Gate Valves

Gate valves can only be fully opened or fully closed. When turning the handwheel, the valve stem only moves up and down (the handwheel position remains unchanged), and the stroke of the gate is equal to the diameter of the valve passage, so the opening and closing time is long. The medium can flow in both directions without any import or export direction requirements.

The stem of the globe valve is a combination of rotation and lifting (with the handwheel rotating together), and the valve disc has a short stroke, allowing it to stop at any position midway. The flow direction is fixed (usually low in and high out), and the medium must push the valve disc from bottom to top to open. It can be opened and closed quickly, but it can only be used in one direction.

Simply put, gate valves are "cut-off specific", while globe valves are "capable of both cut-off and rough adjustment".

Comparison of Flow Resistance and Sealing Performance

This is the core performance difference between the two valves, which directly affects energy consumption and system efficiency.

Gate valves: When it is fully opened, the flow resistance coefficient is only 0.08 to 0.12, and the medium passes almost unobstructed, with a pressure drop close to zero. It's suitable for high traffic scenarios. But when the gate is half open, it will vibrate and the sealing surface is prone to erosion and damage.

Globe valves: The flow resistance is about 35 times that of a gate valve (with a resistance coefficient of about 3.5 to 4.5), and the medium bends and collides with the valve disc, resulting in a significant pressure drop. The sealing performance is better because the valve disc is forcibly compressed by the valve stem force when closed, resulting in less wear.

Secondly, the sealing methods are also different: gate valves rely on medium pressure to self seal (tighter under high pressure), but the sealing surface always rubs and is prone to wear. The shut-off valve is sealed by forced force, resulting in a longer lifespan.

Comprehensive analysis of advantages and disadvantages

Advantages of Gate Valves

Extremely low flow resistance, significant energy-saving effect
Bidirectional flow, installation without direction selection
Large caliber with low cost, suitable for long-distance pipelines
When fully open, it hardly affects the flow of the medium.

Disadvantages of Gate Valves

Cannot be used to regulate flow (half open is prone to vibration damage)
Slow opening and closing, long travel
High height, high installation space requirements
Once there are impurities or wear on the sealing surface, it is prone to internal leakage.

Advantages of Globe Valves

It has certain adjustment performance and can roughly control the flow rate.​
Short opening and closing stroke, easy to operate
Reliable sealing, suitable for high-pressure and high-temperature media
Relatively easy to maintain (some models can replace valve seats online)

Disadvantages of Globe Valves

High flow resistance, long-term operation increases pump power consumption
Unidirectional flow, reverse installation will fail
High driving torque (especially for large diameters)
The price is slightly higher than that of gate valves with the same diameter.
Easy to be eroded and worn in a semi-open state

Comparison of Applicable Scenarios

Typical scenarios for selecting gate valves:
Long distance water, oil, and gas main pipelines (only require switches, no adjustment)

Isolation valves for waterworks and sewage treatment plants

Large caliber low-pressure pipelines in petrochemical industry

Any situation that requires "zero pressure drop" or bidirectional flow

Typical scenarios for selecting shut-off valves:
Control circuits that require frequent flow adjustment (such as boiler feedwater and steam regulation)

High pressure steam, compressed air, and high-temperature oil pipelines

Small diameter pipelines (below DN50) with limited space

In situations where rapid opening and closing or tight sealing are required (such as safety interlock systems)

Conclusion

One sentence mnemonic: "Fully open and fully close, use gate valves for high flow. Use globe valves for adjustment and pressure reduction

In actual projects, it is recommended to first calculate the allowable pressure drop of the system before making a decision. If both can be used, choose the gate valve with lower flow resistance first, which can save electricity and money.

Gate valves and globe valves each have their own battlefield, and there is no absolute good or bad. Only by matching the hard indicators of structure, flow resistance, and regulation capability with the working conditions, can there be no rework in the later stage. After reading this comparison, we will have a clear idea when choosing a valve next time.