Ball valves in Dubai UAE
Ball valves at the Marine Land company use a metal ball with a hole in the center that is placed between two seats to control the flow. Ball valves in dubai have many applications in the hydrocarbon process, and can also handle gases and vapors, and are especially useful for low flow situations. Finally we can say that The Dubai and Sharjah Marine land in the UAE has the best for you.
Ball valves and their working principals
A ball valve is a shut-off valve that controls the flow of liquid or gas using a rotating ball with a hole. By rotating the ball, a quarter of a turn (90 degrees) around its axis, the environment can pass through or be blocked. They are characterized by long life and provide reliable sealing throughout life, even when the valve is not used for a long time. As a result, they are more popular as shut-off valves and gate valves, for example. In addition, they are more resistant to contaminated environments than other types of valves. In special versions, ball valves are also used as control valves. This application is less common than other types of control valves due to the relatively limited accuracy of flow control. However, the valve also has advantages here. For example, even in the case of dirty media, it still ensures reliable sealing.
Common ball valves
Standard ball valves consist of a chamber, a seat, a ball, and a lever to rotate the ball. They include two-, three-, and four-port valves that can be female or male threads or a combination of them. Threaded valves are the most common and come in a variety of forms: with approval for specific media or applications, small ball valves, angled ball valves, ISO-high ball valves, with an integrated filter or exit point and the list goes on. They have a wide range of options and a large operating range for pressure and temperature.
Hydraulic ball valves are specially designed for hydraulic and heating systems due to the high degree of working pressure and hydraulic resistance and heating oil. These valves are made of steel or stainless steel. In addition to these materials, the seats also make hydraulic valves suitable for high working pressure. The seat of these valves is made of polyoxymethylene (POM), which is suitable for high-pressure and low-temperature applications. The maximum working pressure of hydraulic ball valves reaches above 500 bar while the maximum temperature reaches 80 ° C.
Flanged ball valves are characterized by the type of connection. The ports are connected to a piping system through flanges, which are usually designed to a specific standard. These valves offer high flow rates because they usually have a full hole design. When choosing a flange ball valve, in addition to the degree of pressure, you should also consider the flange compression class, which indicates the highest pressure that this type of connection can withstand. These ball valves are designed with two, three, or four ports, can be certified for specific media, have ISO-top, and anything else that a standard quarter-turn valve can have. They are usually made of stainless steel, steel, or cast iron.
Vented ball valves look almost identical to standard two-way ball valves in their design. The main difference is that the outlet valve is closed depending on the environment of the valve. This is achieved with a small hole made in the ball and the body of the valve. When the valve closes, the holes are located next to the outlet port and release the pressure. This is especially useful in compressed air systems that provide a safer workplace pressure relief. Directly these valves are similar to two-way ball valves, while in fact, they are two-way due to the small-bore for ventilation.
The working principle of the ball valve
To understand the working principle of a ball valve, it is important to know the 5 main parts of a ball valve and 2 different types of functions.
The ball is supported and sealed around the valve stem by a ball valve seat and O-ring rings. All are located inside the valve housing. The ball has a hole. When the valve stem rotates a quarter of a turn, the hole either opens to the flow that allows media to pass through it or closes to prevent media flow. The performance of the valve circuit, the chamber assembly, the ball design, and the types of operation are all discussed below on the performance of the ball valves.
The valve may have two, three, or even four ports (2-sided, 3-sided, or 4-sided). The vast majority of ball valves are two-way and operate manually with a lever. When the valve is opened, the lever is in the direction of the pipe. When closed, the handle is perpendicular to the tube. The direction of flow of the ball valve is simply from the inlet to the outlet for a two-way valve. Manually operated ball valves can be closed quickly, so there is a risk of water hammering with fast-flowing media. Some ball valves are equipped with a gearbox. Three-way valves have L or T-shaped holes that affect the operation of the circuit (flow direction). As a result, various circuit functions are available, such as distributing or mixing currents.
The Assembly of the valve chamber can be divided into three common designs: one-piece, two-piece, and three-piece chambers. There is a difference in how the valve is assembled and this affects the maintenance or repair facilities. The function of the valves is the same in each embodiment.
One piece: This is the cheapest type. The two parts that enclose the ball are compressed or welded. Valves cannot be opened for cleaning or maintenance. This type is generally used for low-demand applications.
Two-piece: Two-piece valves can be separated for cleaning, service, and inspection. Often, the parts are connected by a threaded connection. The valve must be completely separated from the pipe to separate the two parts.
Three-piece: Expensive valve often has three pieces. The parts are usually fastened together by bolts. The advantage of this embodiment is that the valve can be serviced without removing the entire valve from the pipeline.
The most common design is the "floating ball design". The ball is hung in the media and held in place by two sealing rings. Some quality valves have a ball design. The ball is supported at the top and bottom to reduce the load on the valve seat.
Most ball valves have a floating ball. The ball is supported by valve seats.
Valves with large diameters and high operating pressures (eg DN> 100mm and 30 bar) often have a Trunnion design. Balls at the bottom and top are supported to reduce the load on the seat rings. Operating torque is usually lower for trunnion valves.
The hole through the ball may have different profiles such as a full hole, a reduced hole, or a V-shaped one.
Most ball valves have a reduced hole. As a result, the valve causes friction losses in the system. These losses are still relatively low compared to other types of valves. One-piece ball valves are almost always slightly perforated.
Full bore valves have a hole diameter similar to a pipe. The advantage is that there are no additional losses in friction and the system is mechanically easier to clean (pigmentation). The downside is that the ball and chamber are larger than a standard bore quarter-turn valve. So the cost is a bit higher and for many applications, this is not required. They are also called full port ball valves.
The hole in the ball or valve seat has a V-shaped profile. As a result, by rotating the ball, the desired flow can be controlled more accurately. By optimizing the profile, a linear flow characteristic can be approached.
Ball valve handle
The handle is connected to the valve stem and can rotate the valve from the open or closed position (90 degrees). If installed correctly, the valve opens when the handle is parallel to the pipe and closes when the handle is perpendicular to the pipe. Paying attention to the direction of the handle is important to visually detect whether the valve is open or closed. There are other types of ball valves, such as locking handles or ball valve hand wheels. They do as their name implies. If you have a larger ball valve or need extra torque to open or close the valve, you may need to open the ball valve handle. If your handle is broken, misplaced, or you are turning the automatic ball valve into a manual one, you can buy a ball valve handle replacement.
Automatic ball valve
Instead of operating the hand knob to turn the valve on or off, some valves can be fitted with an electric or pneumatic actuator. They are connected directly to the valve stem and can rotate it. A quarter turn is the most common flange connection between the valve and the ISO 5211 standard actuator. Using an actuator, you can control your ball valve remotely or via a controller so that it can be used as an automatic shut-off. An active spring ball valve, also called a spring, uses a spring to open/close the valve in the off position and an actuator to hold it in the open/closed position. These are used for energy-saving applications or safety reasons.
There are several different ways for controlling the actuator:
A 2-point controller (also called an open-closed or on-off circuit) uses a control wire in addition to the power cords. When the control wire is turned on, the valve opens electrically. If the control wire is without power, the valve closes (electrically or using a spring).
A 3-point control uses two control wires: one to turn the ball counterclockwise and the other to turn the ball clockwise. Depending on the application, the most appropriate control can be selected.
Some electrical actuators can also provide modulation control, which keeps the ball valve between 0-100% open/closed.
Ball valve housing material
The most common painkillers are brass, stainless steel, and PVC (polyvinyl chloride). The ball is usually made of chrome-plated steel, chrome-plated brass, stainless steel, or PVC. Chairs are often made of Teflon, but can also be made of synthetic materials or other metals.
Brass has the largest market share. Brass is an alloy of copper and zinc and has good mechanical properties. Brass valves are used for (drinking) water, gas, oil, air, and many other media. Chloride solutions (e.g. seawater) or non-mineral water may de-zinc. Zinc removal is a type of corrosion in which zinc is removed from the alloy. This creates a porous structure with greatly reduced mechanical strength. A brass compartment is ideal for an air balloon vent.
Stainless steel ball valve
Stainless steel is used for corrosive and aggressive environments. So, it is often used in seawater, swimming pools, osmosis facilities, high temperatures, and many chemicals. Most stainless steels are austenitic. Types 304 and 316 are the most common, and 316 have the best corrosion resistance. 304 is sometimes referred to as 18/8 because of its 18% chromium and 8% nickel. 316 contains 18% chromium and 10% nickel (18/10). Stainless steel valves usually require higher operating torque than brass or PVC valves. This must be taken into account when a stainless-steel valve is operated by an electric or pneumatic actuator.
PVC is often less expensive (except for ISO-top valves) and is widely used in irrigation, water supply, and drainage or corrosive media. PVC stands for Polyvinyl Chloride. PVC is resistant to most salt solutions, acids, bases, and organic solvents. PVC is not suitable for temperatures above 60 degrees Celsius and is also not resistant to aromatic and chlorinated hydrocarbons. PVC is not as strong as brass or stainless steel, so PVC ball valves have a lower pressure rating.