Rectangular knife gate valve is a special cut-off valve designed with a rectangular cross-section valve body. Its blade-shaped gate moves vertically to achieve full-diameter control of the fluid. It is designed for pipeline systems with high solid content, high viscosity or fiber impurity media (such as sewage, slurry).
1. Structural design and working principle
Rectangular flow channel characteristics
- The valve body channel cross-section is rectangular. Compared with the traditional circular valve body, it effectively reduces the medium siltation, especially suitable for conveying mixed fluids containing fibers and particles, and the pressure loss is reduced by about 20%;
- The gate adopts a rectangular blade design, the thickness is usually 1/5-1/8 of the channel diameter, the shear force is increased by more than 30%, and solid particles with a diameter of ≤3mm can be cut off.
Sealing component configuration
- Floating metal sealing ring combined with PTFE coating, the sealing surface hardness reaches HB200, and the pressure tolerance range is 0.6-1.6MPa;
- The elastic valve seat compensation mechanism can automatically adjust the sealing gap, the wear tolerance is ±0.5mm, and the maintenance cycle is extended.
2. Performance characteristics
Strong anti-blocking ability
The rectangular flow channel and the blade gate can handle mud media containing 30% solid phase, and the anti-blocking performance is 50% higher than that of the circular valve;
Quick cut-off ability
When driven by electric/pneumatic actuators, the full stroke opening and closing time can be as fast as 3 seconds, meeting the emergency cut-off requirements;
Corrosion-resistant design
PVC, stainless steel and other materials are optional, and the acid and alkali resistance covers the medium environment with a pH value of 1-13.
3. Typical application scenarios
| Industry | Specific application scenarios | Technology Compatibility |
|---|---|---|
| Wastewater treatment | Sludge conveying pipeline control | Resistant to fiber entanglement, effectively cuts off sludge agglomerates |
| Food Processing | Fruit residue and sauce conveying system | The full-bore design avoids residue and meets food-grade hygiene standards |
| Mining and Metallurgy | Tailings slurry flow regulation | Wear-resistant valve plate design, life is more than twice that of conventional valves |
4. Selection points
Medium characteristics matching
- When containing solid particles, gates with shearing blades are preferred. If the particle diameter is greater than 5mm, a customized reinforced structure is required;
Drive mode selection
- For high-frequency operation scenarios (>50 times/day), it is recommended to configure a pneumatic actuator, and the torque output stability is better than that of an electric type;
Maintenance convenience
- Models with modular valve seat design can replace seals online, reducing downtime by 80%.
The valve has demonstrated unique advantages in the field of complex media control through rectangular flow channel optimization and enhanced shearing function.
