Gate valves are durable valve types that offer reliable results in the opening and closing of fluids. However, these valves are designed in different types according to the needs of the system. The most common types of gate valves include collapsible (flexible wedge), solid reinforced (solid wedge) and knife gate models. The structural characteristics, durability and performance of each type offer solutions suitable for different conditions. Choosing the right gate valve is critical for efficient and trouble-free operation of the system.
Collapsible type gate valves provide high adaptability to temperature changes thanks to the flexibility of the slide part and increase sealing by fitting better to the gasket. With this feature, they are especially preferred in high temperature systems such as steam and hot water. Solid reinforced gate valves, on the other hand, offer high strength under heavy-duty conditions thanks to their rigid structure and provide a reliable solution in systems where particulate or sedimentary fluids pass. Knife-type gate valves are known for their ability to cut through fibrous, dense or solids-containing fluids with ease, which is why they are widely used in lines with difficult fluids such as wastewater, sludge and pulp.
What is a Foldable Type Gate Valve (Flexible Wedge)?
A collapsible type gate valve is a special type of valve that contains a flexible wedge (slide) in its internal structure, providing high sealing and heat resistance. This valve model, also known as “flexible wedge”, stands out especially with its adaptability to temperature changes in the system. The flexible wedge applies even pressure on the pipeline’s sealing surfaces during closure, ensuring a secure, double-sided seal. Unlike solid reinforced valves, the slide can be slightly tilted to accommodate small misalignments and thermal expansions within the pipe.
These valves are generally preferred in high temperature and pressure environments such as steam, hot water, thermal oil. In temperature fluctuating applications such as industrial boiler systems, power generation plants, heating systems and process lines, they offer a great advantage as they provide constant sealing performance. In addition, thanks to its flexible structure, wear between the gate and seal surfaces is reduced, which significantly reduces maintenance frequency and equipment replacement costs. Collapsible gate valves are a smart and durable solution for systems that require long-lasting performance.
Gate Valve Preference in Industrial Applications
In industrial applications, the choice of gate valve is shaped by the nature of the fluid, the operating conditions of the system and sectoral needs. Each industry poses different challenges in terms of flow control; therefore, the type of valve used is vital for the long-lasting and safe operation of the system. For example, in power generation plants, collapsible gate valves are preferred due to high temperature differences in steam and hot water lines. The flexible gate structure maintains sealing performance by perfectly adapting to the expansion and contraction that occur in these environments.
In water and wastewater treatment plants, knife-type gate valves usually come to the fore. Since there are substances such as sludge, fibrous materials, granular wastes in these systems that can cause clogging, these valves with cutting sliders like knives offer a smooth flow control. In chemical process lines, solid reinforced gate valves are preferred since both chemical resistant material structure and high pressure resistance are important. With their robust structure, such valves also provide reliable sealing in fluids containing particles. Each industrial application has different requirements and determining the appropriate valve type for these requirements directly affects system efficiency.
Technical Criteria to be Considered in Gate Valve Selection
When selecting a gate valve, not only the valve diameter or price, but all technical parameters of the system should be evaluated in detail. First of all, the working pressure and temperature range of the line where the valve will be used should be determined. Compliance of the valve to be selected with these values guarantees both safe operation and long-term performance. The chemical structure of the fluid should also be taken into consideration. For example, stainless steel or special alloy valve bodies should be preferred for corrosive or acidic fluids. Likewise, if the fluid has sediment, particles or fibrous structure, special attention should be paid to the type of gate.
The width of the installation area is also an important criterion in the choice of valve type. Rising stem gate valves allow external observation of open-closed status but require more vertical space; non-rising stem models are preferred in narrow spaces. Valve direction (one-way or two-way operation) and sealing requirements are also decisive factors in the selection. Finally, frequency of operation and ease of maintenance should also be considered. For systems that are frequently opened and closed, models with a durable slide structure should be preferred; for lines that are rarely intervened, models that offer low maintenance requirements should be selected. When all these technical criteria are taken into account, system efficiency is increased and maintenance costs are reduced by choosing the right gate valve.
Solid Wedge Gate Valve (Solid Wedge) Features and Applications
The solid reinforced gate valve is a simple but extremely durable valve model whose gate is completely rigid and monolithic. The “solid wedge” used in this type of valve is inflexible and prevents the passage of fluid by simultaneously applying pressure on both sealing surfaces. The rigidity of the internal mechanism makes these valves especially ideal for systems operating under high mechanical load. The rigid wedge construction cannot tolerate misalignments in the system or small curvatures in the pipe, so the pipeline must be properly installed.
This type of gate valves perform well in lines conveying liquids containing sludge, sediment or particles. It is widely used in heavy duty applications, water treatment plants, agricultural irrigation systems and industrial cooling lines. It also offers a long life and low maintenance solution in environments with constant temperature and pressure conditions. Solid reinforced gate valves are generally preferred for their low cost, robust body and high pressure resistance. However, since sealing may weaken in systems with intense temperature differences, flexible alternatives should be considered in such applications.
What Does Knife Type Gate Valve (Knife Gate) Do?
Knife gate valve is a special type of valve used especially in systems containing solid particles, fibrous materials or dense viscous liquids. These valves, called “Knife gate”, continue on their way by cutting the solids in the fluid like a knife thanks to their thin and sharp sliding mechanism. This design prevents blockages in the pipeline and ensures a smooth flow. One of the biggest advantages of knife valves is that they can safely perform the on-off function even in fluids such as sludge, pulp, granules and waste liquids that tend to leave residue.
Knife gate valves, which are generally preferred in low to medium pressure systems, should be installed considering the direction of use as they provide one-way sealing. These valves are widely used especially in waste water treatment plants, paper and cellulose industry, chemical plants and mining industry. This type of valve, which is very easy to clean and maintain, is both an economical and practical solution thanks to its simple structure. However, its use in high pressure or very high temperature systems may be limited. Therefore, the physical properties of the fluid, pressure level and system direction should be taken into consideration when selecting a knife gate valve.
Which Gate Valve Type is Suitable for Which Environment?
Gate valve selection is a critical decision for safe and efficient operation of the system. Each gate valve type offers different advantages according to operating temperature, pressure level, fluid structure and ambient conditions. For this reason, the technical needs of the system should be well analyzed and the most suitable valve type for the ambient conditions should be determined.
Collapsible gate valves are the ideal solution in systems with high temperature changes thanks to their flexible gate structure. It maintains sealing performance by adapting against thermal expansion, especially in lines carrying steam, hot water or thermal oil. Solid reinforced gate valves, on the other hand, are preferred in systems operating under constant temperature and pressure conditions, containing particulate or sludgy liquids. These models are more robust and pressure resistant. Knife type gate valves are used in systems where viscous, fibrous or solid fluids are transported. They offer an effective solution in demanding environments such as waste water treatment plants, paper production lines and mining. In conclusion, there is no single ideal gate valve for every environment; the right valve should be determined by the conditions of the environment.
Choosing the Right Gate Valve for Maximum Efficiency
Achieving maximum efficiency in a fluid system starts with the right valve selection. Gate valves offer significant advantages such as high performance, energy savings and low maintenance when used in the right application area. However, using the wrong type of gate valve can lead to sealing problems, premature wear and even system failures. Therefore, not only the diameter and pressure values, but also the physical properties of the fluid, temperature range, presence of particles and frequency of operation should be taken into account when selecting the valve.
For example, in systems with frequent temperature differences, flexible collapsible gate valves should be preferred because they are tolerant to thermal expansion. For fibrous or sludgy fluids, a knife-type gate valve is more suitable because it prevents clogging and promotes uninterrupted flow. Solid reinforced valves, on the other hand, stand out in applications where high mechanical durability is required in stable environments. Selecting a valve that is fully compatible with the system not only increases efficiency, but also reduces operating costs by reducing the risk of failure. Therefore, conscious and analysis-based valve selection according to technical conditions is essential for maximum efficiency.
