In the valve industry, gate valves are widely used fluid control devices. Depending on different designs and connection methods, gate valves can be categorized into various types, including threaded bonnet gate valves and regular gate valves. Understanding the differences between them is crucial for selecting the appropriate valve type and ensuring efficient system operation.
1. Valve cover connection method
In a threaded bonnet gate valve, the bonnet is connected to the valve body via threads. This threaded connection makes the bonnet-body connection more compact and reliable, facilitating easier installation and removal.
A regular gate valve's bonnet is typically connected using methods such as flanged connections, bolted connections, or welding. Flanged connections are more common and offer good sealing and strength, but they have a more complex structure, making installation and maintenance relatively cumbersome.
2. Structural Features
The structure of a threaded bonnet gate valve is relatively simple, consisting mainly of the valve body, bonnet, stem, and gate. The stem is fixed to the bonnet through a threaded connection, and the rotation of the handwheel drives the stem to move up and down, achieving the opening and closing of the valve.
Applicable Size: Generally suitable for small diameter pipeline systems, usually below DN50.
The structure of a regular gate valve is somewhat more complex, typically including components such as the valve body, bonnet, stem, gate, and seals. The stem can be connected to the bonnet in various ways, and the handwheel drives the stem and gate to move up and down through a nut or other mechanical device.
Applicable Size: Suitable for small, medium, and large diameter pipeline systems, with a wide range of applications from DN15 to above DN1200.
3. Sealing performance
The sealing performance of a threaded bonnet gate valve depends on the precision of the threaded connection and the selection of sealing materials. It typically employs a soft seal or hard seal structure, suitable for low and medium pressure conditions.
Regular gate valves usually adopt soft seal, hard seal, or metal seal structures, providing reliable sealing performance and the ability to adapt to different pressure and temperature conditions.
4. Installation and Maintenance
The installation of a threaded bonnet gate valve is relatively simple, requiring no complex tools or equipment, making it suitable for the quick installation and replacement in small diameter pipeline systems. Additionally, due to its simple structure, the maintenance of a threaded bonnet gate valve is relatively easy. Particularly, when replacing the bonnet and stem, there is no need to disassemble the entire valve.
The installation of a regular gate valve typically requires specialized installation tools and equipment, especially for large diameter valves, which need lifting and flange alignment. Due to its more complex structure, maintaining a regular gate valve requires more time and effort. Particularly for high-pressure or special condition valves, professional personnel are needed for operation.
5. Application field
Threaded Bonnet Gate Valve: Suitable for low pressure, medium pressure, and normal temperature conditions, such as water supply and drainage systems, HVAC systems, and small industrial pipeline systems.
Regular Gate Valve: Widely used in complex conditions such as high pressure, high temperature, and corrosive media, including large and medium-sized pipeline systems in industries such as petroleum, chemical, power, and metallurgy.
6. Summary