A valve is a device that influences the flow of liquids by opening and shutting down. Valves regulate the flow of liquid in hydraulic, pneumatic, irrigation, plumbing, and motor systems. Valves can operate automatically based on the flow itself or manually based on pressure or temperature. They can also be driven by a motor or manually operated.
By unlocking, shutting down, or partly halting different channels, the valve controls, directs, or influences the flow of a liquid. Needle valves and gate valves are two different types of industrial valves that are often employed for different commercial and residential applications and produced by a reliable valve manufacturer.
What Is Needle Valve
A needle valve can be utilized to control the flow of a substance through an appliance or system, typically water or gas. The presence of a tiny plunger that resembles a needle is the value’s distinctive feature. To make turning the valve simple and accurate, the plunger has a little handle called a handwheel.
The seat, a component of the appliance that is being controlled, is where the elongated end of the valve fits when it is completely connected. A small amount of substance will be able to travel through the needle valve if the valve is twisted, which leads to a gap between the needle and the seat.
One design element of most needle valves requires a significant number of rotations in order to even partially open a gap. This makes it possible to slowly, accurately, and specifically manage how much fluid or gas can travel through the valve.
Furthermore, this enables more effective management and regulation overall and protects gauges from harm that can be caused by abrupt bursts of liquid or gas. Commonly, needle valves manufacturers use strong, long-lasting materials like copper or steel to make these valves. However, based on the precise needs of the valve, plastic and brass valves are occasionally utilized.
What Is Gate Valve
Gate valves, sometimes referred to as knife valves or slide valves, are linear motion valves that enable shut-off by sliding a flat closure element into the flow stream. They are among the most widely used valves in the industry and are manufactured by gate valves manufacturer. A gate valve is a type of control valve that either lets media flow freely through or shuts off the flow of liquid.
Gate valves must only be utilized in the completely open or sealed position, not to control the flow, as they operate more slowly than quarter-turn valves. As gate valves are normally used sparingly, manual gate valves are more economical than automated gate valves with either an electric or pneumatic actuator. Sluice gate valves are another name for gate valves that are frequently used.
When completely opened, gate valves are made to minimize pressure drop across the valve and entirely halt the liquid flow. The procedure liquid goes through a pipe with a diameter that is nearly identical to that of the pipe, and the direction of fluid flow remains unchanged. As a result, when entirely opened, they typically experience little pressure loss.
The fundamental benefit of a gate valve is the clear channel that runs right through it, which results in very little pressure loss over the valve. In contrast to butterfly valves, a gate valve’s unblocked bore permits the pig passage through when washing pipes.
Needle Valve Vs Gate Valve: Main Differences
Check out the primary differences between the gate valves and needle valves in the below section.
Valve Components
- Gate Valve
There are three primary components in a gate valve, which are the valve body, trim, and bonnet. Other parts are wedge, gland, stem, gland flange, seat ring, lantern, yoke, valve port, bonnet bolts and nuts, yoke bush, bonnet gasket, back seat bushing, hand wheel, gland eye bolts and nuts, hand wheel nut, and packing.
- Needle Valve
The needle valves have three primary parts, which are: valve body, stem, and bonnet. The stem combines cords to permit tiny needle modifications associated with the seat. The various parts of the needle valve are: the valve handle, nut, seat, o-ring, stem tip, handle screw, and packing.
Materials
- Gate Valve
The construction of wedge gate valves uses a variety of materials. Cast carbon steel, ductile iron, gunmetal, cast iron, alloy steel, bronze, forged steel, and stainless steel are typical examples of commonly used materials. Plumbing services employ gate valves made of brass and PVC. The liquid service and its design temperature are the two main factors that influence the material choice for gate valves.
- Needle Valve
For metal needles, brass, bronze, stainless steel, or other alloys of steel can be used. For manufacturing elastomeric seats, PTFE, PVC, CPVC, plastics, and thermoplastics are widely used. These valves are accessible with metal to metal, plastic to plastic, or plastic to metal seats and needles.
Types
- Gate Valve
The gate is available in a variety of designs and technological configurations to create reliable sealing for varied purposes. The different types of gate valves are knife gate valves, wedge gate valves, slab gate valves, parallel slide gate valves, and parallel expanding gates.
- Needle Valve
Three different varieties of needle valves are offered on the market, based on the operation style. They are manually operated needle valves, motorized needle valves, and angle needle valves. It is best to get needle valves that are made with quality control measures.
Working Principle
- Gate valve
The operation of a gate valve is very straightforward. The gate of the valve unlocks when it is raised away from the flow route, and the gate valve shuts when it is placed back in place. The hand wheel must be manually spun to move the gate.
The internal threaded mechanism moves the gate vertically while the handwheel turns the valve stem. They are also referred to as multi-turn valves since they require more than one whole cycle of the handwheel to entirely open or completely seal the gate valve. Although they are accessible, electric actuated valves are not economical.
- Needle Valves
The operation of needle valves is possible both manually and automatically. A handwheel is utilized by manually controlled needle valves to open or shut down their disc. The plunger of the handle lifts to open the valve and lets fluid pass through when it is cranked clockwise. The plunger shifts nearer to the seat to reduce the flow rate and eventually obstructs the flow of liquid when the handle is twisted counterclockwise.
Automated needle valves help to open and close the valve automatically by being attached to a hydraulic motor or an air actuator. As per the timer or external data provided into the system and obtained during controlling, the motor or actuator will assist in modifying the plunger’s position. Make sure to acquire valves from a china valve manufacturer as they offer high-quality valves for a reasonable price.
Advantages
- Gate valve
Gate valves are highly sufficient for elevated pressure and temperature-based applications. The primary benefits of resilient gate valves are:
- Deliver extremely reasonable shut-off traits.
- There is little to no requirement for maintenance.
- It retains less pressure drop with relatively limited frictional loss.
- It may be utilized as a bi-directional valve.
- Accessible in different sizes.
- It can be obtainable at an affordable price.
- Needle valve
The major benefits that a needle valve serves are:
- This valve makes it possible to control flow at exceptionally low rates with greater accuracy.
- With this valve, throttling is feasible even with small liquid volumes.
- It is simpler to use.
- Flow rates can be accurately changed.
- The size of needle valves is smaller. Therefore, there would not be a space problem when it is being installed.
Disadvantages
- Gate valve
Here are the primary disadvantages of gate valves:
- They cannot be utilized for throttling purposes.
- Vulnerable to disk and seat wear.
- Dribbling and scraping restorations are hard to perform.
- It might make some sound and vibration if partly open.
- As the disc motion in operation is relatively sluggish, it needs more duration to completely open or close.
- Needle valve
Here are the primary drawbacks of threaded needle valves:
- The elevated liquid flow constraint causes a high-pressure loss in the needle valve.
- Simply looking at the handle position, it is not possible to determine whether it is open or closed.
- They are only suitable for piping systems with low flow rates.
- If the fluid contains solid particles, the seat and needle may be harmed.
- Instantaneous opening or shut down is not possible with the needle valves. It is because sudden operations have the tendency to deteriorate the seat of the needle valve.
Applicable Codes And Standards
- Gate Valve
Here are the codes and standards that handle the slab gate valves’ design specifications:
- For valve design (API 6D, API 600, API 602, API 603, IS780, BS 1414, BS5352, BS 14846)
- API B16.34 for valve pressure-temperature rating
- API 598 for valve pressure testing
- Needle Valve
Here are the most widely utilized design standards and codes when it comes to the design and selection of the needle valve:
- ASME B16.34
- MIL-V-24586
- BS 7174 P4
- PIP PNDMV09N
How To Choose
Depending on the type of application, it is possible to determine which valve to choose between gate valves and needle valves.
Gate valves
Gate valves retain countless industrial and residential based applications, which are as follows:
- Slurries
Gate valves are frequently employed in applications where the material is slurry. It is due to the fact that the slurry can readily move through a gate valve, which has an open passageway for the liquid. Knife gate valves can also quickly and easily slash through the slurry to shut down.
- Viscous media
Gate valves are frequently utilized for media that are viscous, such as light grease and oils. These media can move through the route without any obstructions. Pigging the valve is a typical cleaning technique for these applications. Additionally, the valves used in these applications are frequently turned on or off for extended periods of time.
- Water gate valves
As flow control is often not required for these applications, water gate valves are frequently employed in water applications. The stainless steel gate valve has the potential to completely open or entirely shut down, permitting reasonable water control.
Needle Valves
Because of their capacity to specifically regulate flow rates, needle valves are utilized in almost every liquid control application. They can be utilized for practically any clean gas or liquid by choosing the right valve material and temperature and pressure ratings. Scrutinizing gas flow in a system is one of the most frequent usages of needle valves.
The following fields see considerable use of needle valves:
- For regulating the pressure of water and flow rate, needle valves are utilized in dams, power plants, reservoirs, water distribution systems, and so on.
- In automated combustion control systems, needle valves are used to control fuel flow.
- These valves are frequently employed to turn off pressure gauges or regulate flow rates in flow metering apparatuses.
- Air flow to cylinders is regulated by needle valves, which also regulate piston speed.
Bottom Line
Almost all sectors use needle valves for a staggering variety of applications, including the control and throttle of air, steam, gas, water, oil, and additional non-viscous fluids. The gate valves are utilized for applications that contain viscous media, slurries, and various water-based applications.
For acquiring gate valves and needle valves for your industrial applications, it is best to contact dombor. You can talk to the staff and get instant and affordable quotes for buying bulk quantities of valves.
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