Can globe valves and gate valves be used interchangeably ?
Globe valves and gate valves: functionally similar but not interchangeable :
In fluid pipeline systems, globe valves and gate valves are two of the most common valves with similar appearances. Many users, especially beginners, often have a question: since they both appear to function as “on/off” devices, can they be used interchangeably or mixed?
The answer is: Although temporary substitution is possible under extremely lenient conditions, it is absolutely not recommended to mix them in principle. Incorrect valve selection can lead to reduced system efficiency, increased energy consumption, and even serious safety incidents.
To understand why they cannot be mixed, we need to delve into the core differences between the two.
It is fundamental to understand that they cannot be mixed.
globe valve
Structure: The valve body has a Z-shaped or spherical partition, with a disc-shaped or conical valve disc connected to the valve stem in the middle. By rotating the handwheel, the valve stem drives the valve disc to move vertically in the direction of the fluid, thereby compressing or leaving the valve seat to achieve opening, closing, and adjustment. Working mode: Both adjustment and disconnection are required. It can precisely control the opening, adjust the flow like a faucet, and provide tight closure.
Gate valve:
Structure: There is a wedge-shaped or parallel gate inside the valve body. By rotating the handwheel, the valve stem drives the gate to move vertically in the direction of the fluid, rising or falling like a gate.
Working mode: fully open or fully closed. Its design purpose is to completely clear or cut off the fluid flow, and its structure is not suitable for regulating flow rate.
Globe Valve : Excellent. The distance between the valve disc and the valve seat can accurately control the flow rate
Gate Valve:Extremely poor. When partially opened, the gate will cause severe flushing and vibration of the fluid, which can easily damage the sealing surface, leading to valve failure and internal leakage
(2): Flow resistance :
Globe valve: High. Due to the S-shaped flow channel, the fluid direction changes multiple times, resulting in significant pressure loss (pressure drop).
Gate valve: Extremely low. When fully open, the flow channel is straight through, the gate is completely raised, and the resistance is close to the pipeline itself.
(3): Sealing performance:
Globe valve: Usually very good, the sealing surface between the valve disc and the valve seat is not easily washed away by the flowing medium.
Gate valve: It works well when fully open and fully closed, but the sealing surface is prone to damage and internal leakage during adjustment and use
Globe valve: In situations where regulation, throttling, and frequent operation are required. For example, adjusting flow rate, pressure, sampling ports, instrument valves, etc.
Gate valve:In situations where it is fully open or fully closed and not frequently operated. For example, main pipeline isolation, equipment isolation, and maintaining a fully open state for a long time.
3、 When can it be temporarily replaced?
Temporary replacement can only be considered in extremely special and helpless situations: when a gate valve in the system is completely damaged, a globe valve of the same pressure level and diameter is needed to temporarily achieve the function of “fully open” or “fully closed” to maintain short-term operation of the system, and the correct valve should be replaced as soon as possible.
Please note that even temporary replacements must ensure:
The shut-off valve must be installed correctly (pay attention to the flow direction).
Only used for “on” or “off”, absolutely not for adjustment
Accept the fact that there is a significant pressure drop at this system point.
4、 How to choose correctly? Summary and Guidelines
The selection of valves is not based on convenience, but on functional requirements.
Please select a shut-off valve when you need to:
Adjust the flow rate or pressure.
It needs to be frequently turned on and off.
Significant pressure loss is allowed at the valve location.
In situations where there is less possibility of leakage from the valve stem packing box to the outside (the pressure of the shut-off valve can be released upwards).
Please choose a gate valve when you need:
Completely cut off or connect the fluid without the need for adjustment.
Require lower flow resistance and pressure drop (such as pump outlet, main pipeline).
The valve remains in a fully open or fully closed state for a long time and is not operated frequently.
