An industrial globe valve and a needle valve are typically employed in civil and industrial piping systems to start, stop, and regulate media flow. Both are suitable for use with a wide range of gas, fluids, and applications where a tight seal and flow control, also referred to as throttling, is required.
The shape of their closing mechanism, i.e., the disc, helps reduce the turbulence in a flow, making them ideal for applications requiring efficient flow control. If the disc is small, it is called a needle valve and is suitable for more precise flow control. Its operating mechanism ensures a progressive closure, vital when the fluid flow requires rapid blocking without damaging the pipeline, i.e., the water hammer effect.
On the other hand, the design of a globe valve is responsible for a consistent pressure drop that should be considered during pipeline installation and setup. Although these valves are similar, they have a few differences making them irreplaceable. So let’s not waste more time and discuss everything about a needle valve vs globe valve and the features differentiating them.
Everything to Know About a Needle Valve:
In an industrial piping system, there are many ways to isolate the fluid flow. Needle valves, commonly known as plunger valves, are employed to fulfil this purpose. They control and regulate the fluid flow and pressure in a pipeline. This linear-motion valve, bought from a reliable China valve manufacturer, features a needle-like plug and a port arrangement. Although they are small, they can control the flow with high accuracy.
A needle valve features a small plunger in the shape of a needle to isolate the fluid. The plunger has a handle for easy and precise operation of the valve. When the plunger is attached to the valve, its extended end fits perfectly into the seat. When the valve opens by mistake, the space between the needle and seat is so tiny that minimal fluids can pass through.
The most common parts of a needle valve include the valve body and seat, a stem and tip, and the packing and bonnet. Its stem incorporates fine threads to permit micrometre needle adjustments relative to the valve seat. Its parts include a handle, nut, bonnet, body, o-ring, stem, packing, seat, and handle screw. It is usually brass, stainless steel, bronze, and other materials.
Application of a Needle Valve in Various Industries:
- A needle ball valve is used in gas bleeder lines as a throttle valve.
- With sample points in piping with a nominal flow rate.
- To control the flow movement in all analog field instruments.
- Metering applications include air, gas, oil, steam, and water.
- In automated combustion control systems for accurate flow regulation.
- In pressure pump governors to reduce fluctuations in pump discharge.
Everything to Know About a Globe Valve:
In industrial pipelines, a globe valve is used to start, stop, and regulate a fluid flow with the help of a closure member or a disc. It is a liner-motion closing-down valve that moves a disc into and out of the seating surface to regulate the media. Since it features a globular-shaped cavity near the port region, it is called a globe valve.
The disc of a globe valve regulates the flow through a seat that opens proportionately with the disc. It is ideal for throttling and controlling fluid flow in small pipes. When it is in operation, the disc moves perpendicular to the seat helping in the opening or closing of the valve. Due to the short distance of the disc between different positions, globe valves are an idea if an operation requires frequent opening and closing.
Depending on the design of the valve seat and disc, its seating load is positively controlled by a screwed stem. Since its sealing capacity is high, it is employed in various applications for on or off duty if the resistance from tortuous flow passage is acceptable. A China actuated globe valve for low-flow resistance is also used in on-off duty.
A globe valve usually constitutes a globular-shaped body, bonnet, disc or plug, stem, yoke, seat ring, gland bushing and flange, sleeve, gland bolt and nuts, handwheel, backseat, packing, and pressure seal gasket.
Application of a Globe Valve in Various Industries:
- In water cooling systems requiring flow regulation.
- The fuel oil systems demand leak-tightness and turbine seals.
- In control valve bypass systems, high-point vents, and low-point drains.
- In boiler vents, steam services, steam vents, gutters, and heater drain.
- Oil and gas, feedwater, chemical feed, refinery, and air condenser extraction.
How are Needle Valve and Globe Valve Different?
A needle valve is used in any industry where continuous throttling is required to regulate a flow. Although it is like a globe valve in design, the sharp, needle-like disc shape of a needle valve is the significant difference between the two types. According to needle valves manufacturers, they are like a globe valve where the plug is in the shape of a needle instead of a disc, offering fine flow control in precision equipment.
A needle valve is perfect for applications where precise flow measurement is required. It is used in industries where control or metering of steam, gas, air, water, oil, and other non-viscous liquid usually passes through the pipeline. It is widely used in power generation, instrumentation control, cooling, zoological sciences, and gas and liquid dispensation industries.
A globe valve also operates similarly. Its primary function is to start, stop, or regulate a media flow by shifting the disc upwards to allow the fluids to flow proportionately. Although it works as an on or off valve, it is also suitable for throttling. It has a good sealing capacity and short stroke and allows convenient machining or resurfacing of the valve seat.
Here is a quick table to understand the basics of needle valve vs globe valve so that a person can pick one according to its suitability in a particular application:
|BASIS OF DIFFERENCE||NEEDLE VALVE||GLOBE VALVE|
|PURPOSE||A needle valve is used where continuous throttling is required to regulate a flow.||A globe butterfly valve is used where a flow is needed for flow control or throttling.|
|PLUG SHAPE||A needle valve features a needle-shaped plug.||A globe valve features a disc-shaped plug.|
|SIZE||The size of a needle valve is smaller than a globe valve.||The size of a globe valve is more significant than a needle valve.|
|APPLICATION||It is helpful in precision equipment as it offers an outstanding level of flow control.||A wholesale actuated globe valve is helpful in operations requiring frequent opening and closing.|
|INDUSTRIES||It is used in gas bleeder lines, analog field instruments, metering applications, automated combustion control systems, and pressure pump governors.||It is used in water cooling, fuel oil, drain, chemical feed, feedwater, control valve bypass, oil and gas, refinery, air condenser extraction, and boiler vent systems.|
Hopefully, this table helps everyone understand needle valve vs globe valve so they can pick one according to an application. Although these two designs have multiple similarities, they have a few differences, making them irreplaceable in a specific application. If an application requires a globe valve, one cannot replace it with a needle, no matter how similar their usage is.
Since the two valve designs are extensively used today in several applications, please contact us to buy them in high quality. These differences will help decide the ideal valve for a particular application.