4inch Stainless Steel Flanged Low Pressure Knife Gate Valve Driven by Electric Actuator

Stainless Steel Flanged Knife Gate Valve with Electric Actuator for Slurry, Wastewater, and Industrial Solid-Laden Media Control

I. Product Overview

TIANYU stainless steel flanged knife gate valve with electric actuator is a high-performance industrial valve engineered for precise flow control in harsh environments containing solids, slurries, or fibrous media. Crafted from premium stainless steel (304/316), this valve combines a sharp, wedge-shaped gate for cutting through viscous media with a robust electric actuation system for automated operation. Its flanged connection ensures secure integration into pipelines, while the resilient sealing design guarantees tight shutoff even with abrasive materials. Ideal for wastewater treatment, mining, pulp and paper, and chemical processing, this valve excels in applications where conventional valves fail due to clogging or seal wear, delivering reliable performance with minimal maintenance requirements.

II. Key Attributes and Specification Parameters

Basic Attributes

Structure Design: Knife gate valve featuring a sharpened, tapered gate (15° wedge angle) designed to slice through solids, fibrous materials, and slurries, preventing media buildup and valve jamming. The gate moves vertically within the valve body, with guided travel ensuring precise alignment with the seat for consistent sealing—a critical improvement over flat-gate designs in dirty media applications.
Body Material: Stainless steel (304 or 316), selected for superior corrosion resistance. 304 stainless steel offers excellent resistance to water, steam, and mild chemicals, while 316 grade adds molybdenum for enhanced protection against chloride corrosion, making it suitable for coastal, marine, or high-salt environments. Both grades provide tensile strength ≥515MPa and elongation ≥40%, ensuring durability under pressure.
Sealing System: Dual-component sealing combining resilient and metallic elements:
- Primary seal: EPDM or PTFE elastomer seated in a machined groove, providing bubble-tight shutoff for liquid media. EPDM offers excellent flexibility and temperature resistance, while PTFE excels in chemical compatibility.
- Secondary seal: Metal-to-metal backup seal on gate and seat surfaces (stainless steel), activating under high pressure or abrasive conditions to prevent leakage if the primary seal wears.
Pressure Rating: PN10 to PN16 (1.0MPa to 1.6MPa), suitable for low to medium-pressure systems such as slurry pipelines, wastewater channels, and industrial process lines.
Temperature Range: -20℃ to 120℃ with EPDM seals; -20℃ to 200℃ with PTFE seals, accommodating both cold fluids (groundwater, chilled water) and moderately heated media (process water, low-pressure steam).
Nominal Diameter Range: DN50 to DN600, covering pipeline sizes from small-scale industrial lines to large municipal wastewater mains.
Connection Type: Flanged ends conforming to ASME B16.5 (Class 150) and GB/T 17241.6 standards. Flanges feature precision-drilled bolt holes for alignment with pipeline flanges, ensuring leak-free installation with compatible gaskets.
Electric Actuator: Multi-voltage (24V to 240V AC/DC) motorized actuator with gear-driven operation. Equipped with position feedback sensors, manual override, and IP67 weatherproof enclosure for reliable performance in harsh environments. Actuation time for 90° gate movement is 9–15 seconds, with adjustable torque settings to prevent motor burnout.
Media Compatibility: Designed for water, wastewater, sewage, mining slurries (coal, iron ore), pulp, paper stock, chemical slurries, food processing by-products, and other media containing solids up to 30% concentration by volume.
Design Standards: Complies with MSS SP-81 (knife gate valve specifications) and GB/T 12234 (gate valve general standards), ensuring compatibility with global pipeline systems.

Flanged knife gate valve driven by electric actuator

Knife gate valves are manufactured in two forms, non-rising stem and rising stem, according to different calibers (non-rising stem for DN200~900mm, rising stem for DN50~900mm). The fully circular straight-through channel design prevents slag accumulation and jamming. The bottom end of the knife plate is processed into a blade shape, which has a cutting function for loose materials such as fibers, pulp, and wood pulp, and at the same time has good opening and closing effects. A hard polytetrafluoroethylene mud scraper is installed on the upper end of the knife plate, which can prevent abrasive substances such as dust and gravel from entering the stuffing box, significantly extending the service life of the knife plate. The valve plate is made of stainless steel and undergoes precision grinding and polishing to achieve the best sealing effect. A knife gate valve is a flat valve plate with a knife-shaped bevel cut at the bottom, which has the function of cutting the medium, so that the closing of the valve is not blocked by the medium. Knife gate valves are also known as knife door gate valves and knife-type slurry valves. Their opening and closing part is the gate plate, and the movement direction of the gate plate is perpendicular to the direction of the fluid. The blade-shaped gate plate that can cut fiber materials is used to cut off the medium. Knife gate valves can only be fully opened and fully closed, and cannot be used for regulation and throttling.

Product Overview

III. Product Features

TIANYU stainless steel electric knife gate valve offers distinct advantages tailored to challenging media conditions:

- Sharpened Gate for Uninterrupted Flow: The precision-ground, 15° tapered gate acts as a cutting blade, slicing through fibrous materials (e.g., paper pulp, sewage rags) and breaking up solid agglomerates. This eliminates clogging—a common issue with ball or butterfly valves in slurry applications—and ensures smooth operation even with high-solids media.
- Corrosion Resistance: 304/316 stainless steel construction resists rust, chemical attack, and pitting from aggressive media such as saltwater, acidic wastewater, or mineral-laden slurries. The valve body undergoes passivation treatment to enhance the chromium oxide protective layer, extending service life in outdoor or humid environments.
- Automated Electric Actuation: The multi-voltage electric actuator enables remote control and integration with SCADA systems, ideal for hard-to-reach locations (e.g., underground sewage pits) or large-scale industrial facilities requiring centralized operation. Position feedback provides real-time status monitoring, while manual override ensures operation during power outages.
- Tight Sealing Under Variable Conditions: The resilient EPDM/PTFE primary seal conforms to surface irregularities, maintaining shutoff even with minor gate wear. Under high pressure or abrasive conditions, the metal backup seal engages to prevent leakage, ensuring safety in critical applications like chemical transfer.
- Flanged Connection Reliability: Flanged ends distribute pressure evenly across the connection, reducing leakage risks compared to wafer-style valves in high-vibration environments. Compliance with ASME and GB standards simplifies retrofitting into existing pipelines without modifications.
- Low Maintenance Design: The gate and seat surfaces are polished to minimize friction, reducing wear and extending service intervals. The actuator’s self-lubricating gears and sealed housing require no regular maintenance, while replaceable seals allow for easy repair without removing the valve from the pipeline.
- Bubble-Tight Shutoff: The elastomeric primary seal achieves API 598 Class VI leakage rates (near-zero leakage) for clean liquids, transitioning to effective sealing for slurries as the gate cuts through media and compresses solids against the seat.1. Simple shape, super short structure length, save material, can greatly reduce the overall weight of pipeline system, wide application range.
  2. Occupy a small effective space, can effectively support the strength of the pipeline, can reduce the possibility of pipeline vibration.
  3. Austenitic stainless steel is selected for the gate, which greatly improves the corrosion resistance and can effectively
  prevent sealing leakage caused by the corrosion of the gate.
  4. The upper sealing packing adopts flexible PTFE, reliable sealing, light and flexible operation.
  5. The gate plate has the function of knife, which can effectively break all kinds of sundries in the medium.

IV. Manufacturing Process

TIANYU adheres to stringent manufacturing protocols to ensure the durability and performance of its knife gate valves:

Material Selection and Testing: Stainless steel raw materials (304/316) undergo chemical composition analysis and mechanical testing (tensile strength, elongation) to verify compliance with ASTM A182 standards. Each batch is inspected for corrosion resistance via salt spray testing (500 hours for 316 grade).
Precision Machining: The gate is CNC-machined to achieve a sharpened edge (±0.05mm tolerance) and smooth surface finish (Ra ≤1.6μm) to minimize friction and enhance cutting efficiency. Valve body internal surfaces are honed to remove burrs, preventing media buildup.
Seal Integration: EPDM/PTFE seals are bonded to the seat groove using high-temperature adhesive, ensuring permanent attachment even with thermal cycling. The seals undergo compression testing to verify elasticity and resistance to media absorption.
Actuator Calibration: Electric actuators are integrated with the valve stem, with gear trains adjusted for smooth operation. Position sensors are calibrated to ensure accurate feedback (±1% full scale), and torque limits are set to prevent overloading during jamming.
Assembly and Quality Control: The gate is installed with guided bushings to ensure vertical alignment. Flange faces are machined to flatness (≤0.1mm/m) for proper gasket seating. Each valve undergoes:
- Shell test: 1.5×nominal pressure (hydrostatic) to verify body integrity, with no visible leakage or deformation.
- Seat test: 1.1×nominal pressure using water or air, ensuring leakage rates meet API 598 Class V standards.
- Actuation test: Full open/close cycles to confirm smooth operation, with position indicator verification.

V. Product Advantages

TIANYU stainless steel electric knife gate valve delivers superior performance in demanding applications:

Clog Prevention: The sharpened gate design eliminates media buildup, reducing downtime from valve jamming—a critical advantage over ball valves or conventional gate valves in sewage, pulp, and mining applications.
Extended Service Life: Stainless steel construction and wear-resistant seals withstand abrasive media, extending service life to 10+ years in typical wastewater applications, outperforming ductile iron valves by 50% in corrosive environments.
Operational Efficiency: Electric actuation reduces labor costs associated with manual operation, while remote monitoring enables predictive maintenance. The valve’s low pressure drop (Cv value ≥200 for DN100) minimizes energy consumption in pumping systems.
Versatility Across Industries: Compatible with diverse media (from clean water to acidic slurries) and temperature ranges, eliminating the need for multiple valve types in mixed-process facilities.
Safety and Compliance: IP67-rated actuator enclosure protects against dust and water ingress, ensuring safe operation in outdoor or wet environments. Compliance with MSS SP-81 and GB/T standards facilitates integration into global projects.
Easy Installation and Retrofit: Flanged connections align with industry standards, simplifying installation in existing pipelines. The valve’s compact design requires minimal space compared to knife gate valve with extended bodies.

Application

VI. Product Applications

TIANYU stainless steel electric knife gate valve is trusted in industries requiring reliable control of solid-laden media:

Wastewater Treatment: Used in sewage lift stations, sludge processing lines, and filter backwash systems, where the sharp gate cuts through rags, grit, and biological sludge to prevent clogging.
Mining and Mineral Processing: Deployed in slurry pipelines transporting coal, iron ore, or copper concentrate, with 316 stainless steel options resisting corrosion from mineral-laden water.
Pulp and Paper: Integrated into stock preparation, black liquor, and wastewater lines, slicing through wood fibers and pulp solids to maintain consistent flow.
Chemical Processing: Suitable for transferring abrasive chemical slurries (e.g., limestone slurry in flue gas desulfurization), with PTFE seals ensuring compatibility with acidic or caustic media.
Food and Beverage: Used in processing lines handling fruit pulps, vegetable wastes, or grain slurries, where stainless steel construction meets hygiene requirements (316 grade optional for high-purity applications).
Municipal Infrastructure: Installed in stormwater drains, water treatment plants, and irrigation systems, providing reliable shutoff even with debris-laden water.

TIANYU stainless steel flanged knife gate valve with electric actuator excels in controlling slurries, wastewater, and solid-laden media. Its sharp gate prevents clogging, stainless steel resists corrosion, and electric actuation enables automated control. Ideal for mining, wastewater, and pulp industries. Customizable with 304/316 stainless steel, EPDM/PTFE seals, and voltage options, ensuring tailored performance for specific applications.