The core difference between the wafer knife gate valve and the lug knife gate valve lies in the connection method and application characteristics. The specific differences are as follows:
1. Connection method
Wafer knife gate valve
There are no independent flanges at both ends of the valve body. It is clamped and fixed by the pipe flanges on both sides, and the installation is completed by long bolts penetrating the valve body and the flange holes.
The structure is compact and lightweight, suitable for space-constrained scenarios, but the installation requires precise alignment of the pipe flange, otherwise it is easy to cause leakage due to uneven force.
Lug knife gate valve
The lug structure with bolt holes is designed on both sides of the valve body. When installed, it is directly fixed to the pipe flange by bolts without additional clamping devices.
It is divided into two types:
Through-type pressure hole: The installation method is similar to the wafer type, but the stability is better than the wafer type;
Threaded hole pressure hole: The bolts are directly screwed into the lug threaded holes of the valve body for fixing, and the stability is close to the flange connection.
2. Performance Comparison
| Characteristic | wafer knife gate valve | ligged knife gate valve |
|---|---|---|
| Ease of installation | Quick installation but flange alignment required | Threaded hole lugs for easier installation |
| Structural stability | Relies on flange clamping, susceptible to installation errors | Bolts are directly fixed, the force is even and more stable |
| Sealing performance | Reliable in medium and low pressure environments, but prone to leakage at high pressure | Elastic seal design, better performance under high pressure |
| Applicable pressure level | Typically used in medium and low pressure systems | Can adapt to higher pressure and temperature conditions |
3. Application scenarios
Wafer-type knife gate valve
Applicable to narrow space scenarios such as building water supply and drainage, small equipment pipelines, etc.;
Common in control systems for light media (such as clean water and gas), with low cost.
Lug-type knife gate valve
Mostly used in heavy industrial fields such as petroleum, chemical industry, and smelting, especially suitable for corrosive media or pipeline systems that require frequent maintenance;
Threaded hole lug valves have more advantages in high vibration environments.
4. Selection recommendations
Prioritize the wafer type: Applicable when the budget is limited, the space is compact, and the medium working conditions are mild; Prioritize the lug type: Industrial scenarios with high pressure, high temperature, corrosive media, or frequent disassembly and maintenance.
