Specification

DN100~DN300 PN16 Stainless Steel Manual Flange Knife Gate Valve

I. Product Overview

TIANYU stainless steel knife gate valve is a specialized flow control solution engineered for industrial systems handling media with high solid content. Crafted with stainless steel (and optional cast steel), it features a sharp-edged gate design and flange connection to ensure reliable shut-off and flow regulation of slurries, sludge, and viscous fluids. Operating at ordinary temperature and medium pressure (up to 1.6MPa), it combines durability with ease of operation—ideal for wastewater treatment, mining, pulp & paper, and chemical processing industries. Compliant with GB standards and ISO 9001 certification, it balances cutting performance, corrosion resistance, and low maintenance, addressing the challenges of handling abrasive or semi-solid media.

II. Key Attribute Parameters

Size Range: DN100~DN300 (4″~12″), covering medium to large-diameter pipelines for industrial flow systems with high solid content.
Pressure Range: 1.0MPa~1.6MPa (150LB, 5K~10K), suitable for low to medium pressure applications such as sludge transfer and pulp pipelines.
Temperature Range: Ordinary temperature (typically -10℃~80℃), compatible with ambient and moderately heated media in general industrial environments.
Material Configuration:
- Body & Bonnet: Stainless steel (304/316) for corrosion resistance; optional cast steel for cost-sensitive non-corrosive applications.
- Gate: Stainless steel with sharpened edge (hardness ≥HB200), designed to cut through solids and viscous media.
- Seal: Elastic seal (EPDM/PTFE), ensuring tight shut-off and resisting wear from abrasive particles.
- Stem: Stainless steel (304/316), with threaded design for smooth lifting/lowering and resistance to rust.
- Actuator: Manual (handwheel) with optional pneumatic/electric actuation for automated systems.
Connection Type: Flange (per GB/ANSI/DIN standards), enabling secure integration with pipeline flanges and easy installation.
Applicable Media: Water, oil, air, slurries, sludge, pulp, and other fluids with suspended solids.

Product Overview

III. Features Description

Sharp-Edged Gate Design: The gate features a precision-sharpened edge (angle ≤30°) that cuts through accumulated solids, sludge, or viscous media when closing—eliminating blockages that cause leakage in standard gate valves. This ensures reliable shut-off even in pipelines with semi-solid residues.
Stainless Steel Corrosion Resistance: 304/316 stainless steel body and gate resist corrosion from water, mild chemicals, and humid environments, avoiding rust-related jamming. This is critical for wastewater treatment and chemical processing, where media may contain corrosive components.
Elastic Seal Performance: The EPDM/PTFE seal forms a tight bond with the gate, preventing leakage of media with fine solids. The seal is recessed to avoid direct contact with abrasive particles, extending its service life by 50% compared to exposed seals.
Compact Structure: The valve body has a streamlined design, requiring less installation space than globe valves. This is advantageous in industrial plants with limited pipeline clearance, such as mining slurry systems.
Manual Operation Efficiency: The handwheel is paired with a worm gear reducer, reducing operating torque by 40% and enabling one-person operation of large-diameter valves (DN300). The stem’s clear lifting/lowering movement provides visual confirmation of valve position.

IV. Manufacturing Processes

Material Preparation: Stainless steel plates undergo ultrasonic testing to detect internal defects. Chemical composition analysis verifies alloy content (Cr18-20% for 304; Cr16-18%, Mo2-3% for 316) to ensure corrosion resistance.
Gate Sharpening: The gate edge is precision-ground using CNC grinders to achieve a sharp, uniform angle (tolerance ±1°). This ensures consistent cutting performance across the entire gate width.
Body & Bonnet Machining: CNC lathes machine the valve body and bonnet to tight tolerances (±0.05mm), ensuring the gate moves smoothly without jamming. Flange faces are finished to Ra ≤1.6μm for leak-tight gasket sealing.
Seal Assembly: The elastic seal (EPDM/PTFE) is vulcanized or bonded to the valve seat, with pressure testing (0.6MPa air) to verify adhesion. This prevents seal detachment under repeated gate movement.
Testing:
- Hydrostatic Test: Body tested at 1.5×rated pressure (2.4MPa for PN16) for 30 minutes; seat tested at 1.1×rated pressure (1.76MPa) with water to confirm no leakage.
- Operation Test: 100+ open/close cycles to ensure smooth gate movement and no jamming, with special focus on cutting performance in slurry Mock test.
- Corrosion Test: Stainless steel components undergo 48-hour salt spray testing to validate resistance to rust and oxidation.

Valve Details

V. Product Advantages

Solids Handling Capability: The sharp gate cuts through sludge, pulp, and solids, avoiding blockages that plague standard valves—reducing downtime for cleaning by 60% in mining and wastewater applications.
Corrosion Resistance: Stainless steel construction eliminates rust-related failures, extending service life to 8+ years in humid or mildly corrosive environments.
Tight Shut-Off: Elastic seals and precision gate design achieve ANSI/FCI Class IV leakage, preventing media loss and environmental contamination in hazardous applications.
Easy Maintenance: The flange connection and modular design allow gate or seal replacement without removing the valve from the pipeline, minimizing maintenance time.
Cost-Effectiveness: Simple structure and manual operation reduce initial investment, while durable materials lower long-term replacement costs—ideal for budget-conscious industrial projects.

Application

VI. Application Fields

Wastewater Treatment: Controls sludge, sewage, and grit-laden water flow in treatment plants, with the sharp gate cutting through debris to prevent pipeline clogging.
Mining Industry: Regulates mineral slurries (e.g., coal slurry, iron ore slurry) in transfer lines, leveraging stainless steel’s wear resistance and cutting capability.
Pulp & Paper: Manages wood pulp and paper stock flow, where the gate’s cutting edge breaks up fiber clumps and ensures uniform flow to processing equipment.
Chemical Processing: Handles viscous chemicals and slurries (e.g., pigment mixtures), with 316 stainless steel resisting corrosion from mild acids and solvents.
Food Processing: Controls fruit pulps, grain slurries, and waste by-products, with stainless steel meeting hygiene standards and avoiding media contamination.