Specification

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

I. Product Overview

NEWWAY 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.