Valve Types

Gate valves are in the group of valves that open and close with multiple turns and are widely used. Gate valves come in many types, including various sizes, materials, temperature and pressure values, as well as cover and body designs. Gate valves are designed to operate with fully open or fully closed function. Therefore, they cannot be used as control or regulating valves. It is also not suitable for precise flow control.

 

Gate valves are generally used when a minimum pressure drop and free bore is required. When fully opened, there is no obstruction of the slide in the flow path resulting in a very low pressure loss. Since the gate valve is a multi-turn valve, the valve is operated by a threaded shaft. Slow running also prevents the effects of water hammer, as the spindle has to rotate several times to switch the slide from open to closed.

 

Gate valves operate by closing and opening the fluid passage with a slide or disc that slides perpendicular to the passage direction. Fluids in which gate valves are used; Fluids consisting of hot water, compressed air, fuel oil and chemicals can be shown.

 

Gate valves are produced in ANSI norm and API 600-602 standards

Globe valve is the most commonly used valve type in installations all over the world. The technology of these valves, like all frequently preferred products, is developing rapidly. They are suitable for frequent open closure, durable and long-lasting. Globe valves offering precise flow control are suitable for use at high pressure and temperature. The most important reason why these valves are preferred frequently is the sealing they successfully provide at three different points. These valves owe the circuit sealing to the system that closes with the site pressing of the rotating valve flywheel, and provides external sealing with two different solutions. It guarantees the tightness between the body and the cover with a gasket, and the tightness from the actuating shaft to the outside environment with packing rings.

 

Globe Valve Types

Globe valve, which is the most frequently used valve type in installations all over the world, has three different sealing methods.

 

Pressed Globe Valve

The sealing system in pressure type valves is made by closing the valve, which is a metal closing element, by sitting on a metal disc. In other words, the sealing system is in the form of metal-metal.

 

Metal Bellows Globe Valve

The shaft sealing systems of these valves have been developed with stainless steel bellows. In other words, the sealing system out of the shaft bearing of the valve is supported by the bowl-bellows-shaft system installed between the cover and the body. In addition, there is a packing group as a temporary solution against the risk of leakage as a result of the problems that may occur in the bellows.

 

Piston Globe Valve

The sealing system of piston type valves is metal-elastic. These valves have two ring-shaped elastic rings and a piston that goes into them. This piston acts as a closing element. It wraps the piston inside the pressure rings coming from the cap nuts with radial pressure. Tightness is provided by this pressure. Unlike other globe valves, residues and impurities that may occur in the circuit are also cleaned thanks to the closing way of the piston.

Globe valves, which are resistant to high pressure and high temperatures, provide precise flow control as well as these features. The main headings used in the fluid control of globe valves with higher pressure losses compared to other valves are as follows.

Ball valves take their name from the perforated and rotating ball inside. Basically, the flow through the system is controlled by rotating it at 90 degrees with the help of the handle on the perforated ball valve. When the valve stem is aligned with the flow, the bore of the sphere is also in line with the flow and the fluid is completely free. When the handle is turned 90 degrees perpendicular to the valve, the system shuts down and the flow is cut off. Ball valves are preferred in places that open and close frequently or need to open and close quickly. Ball valves are one of the frequently preferred metal valve types due to their good sealing properties, low pressure loss, easy opening and closing, and small space in the pipeline.

There are sub-types of ball valves suitable for different needs. For example, the natural gas ball valve used in the natural gas installation must be produced in accordance with EN 331 European standards. Among some other types of ball valves, flanged ball valves used in systems where leakage is a priority or ball valves with butterfly levers used in narrow spaces where the normal arm cannot turn can be cited as examples.

Ball valves are a type of metal valve used in many industries with their lightness, ease of use, small footprint, low pressure loss and good sealing properties. Ball valves, which we are used to seeing especially in drinking water installations and natural gas installations in buildings, are frequently used in these areas as well as these most familiar areas.

Check valves are safety armatures that prevent fluid from returning in fluid transfer systems. There are many types of check valves that can be selected according to the system needs and other criteria. The main factors that are taken into consideration when choosing a check valve are pressure loss, closing feature and costs. Check valves are valves that allow unidirectional flow of fluid. These equipments, which provide this with ball, spring or conical structures, are used for different reasons in different installations. In systems such as LPG motor vehicles, where the return flow will adversely affect the operation of the system, the check valve provides system stabilization, while in hydraulic systems, it prevents the pressure created by the return of the fluid.

There are different types of check valves used for different purposes in different systems, suitable for the process and the fluid used. Certain header check valve types are as follows.

Butterfly valves are a versatile type of valve used in opening, closing and flow rate adjustment. Butterfly valve is an economical valve type that takes up little space in the pipeline, provides perfect sealing feature in both directions, can be adapted to automation easily and economically, works with low pressure losses. These features have made the butterfly valve a preferred product in many systems since the 1960s when it was first designed. There are two types of butterfly valves, wafer and lug, used in many areas such as fire extinguishing installations, water and wastewater installations, power stations, compressor lines, air handling units, treatment centers.

Since each flange has its own bolts in Lug type butterfly valves, it is possible to clean, inspect and repair the valve without completely closing the system. On the other hand, wafer type butterfly valves are designed to prevent back flow in unidirectional flow systems. They have high impermeability and protect the system against bidirectional pressure difference.

Butterfly valve is frequently used in many areas as an economical valve that takes up little space in the pipeline, provides perfect sealing feature in both directions, can be easily and economically adapted to automation, works with low pressure losses. These valves, which are used in different fluid applications in different sectors with their sub-types, are one of the most preferred valve types.