DN80 Knife Gate Valve (3 Inch)

The DN80 knife gate valve delivers exceptional performance and reliability for demanding 3-inch pipeline systems. Engineered for heavy-duty industrial applications including mining, pulp & paper, wastewater treatment, and chemical processing, this valve provides superior cutting action through the toughest media while maintaining zero-leakage shut-off performance in continuous operation environments.

Key Applications: Mining & Slurry • Pulp & Paper • Wastewater Treatment • Chemical Processing • Power Plants • Steel Mills • Cement Plants

Why Choose DN80 Knife Gate Valve?

✓ Heavy-Duty Performance

Robust 3-inch design for continuous industrial operation
Enhanced structural integrity for high-pressure applications
Superior flow capacity (Cv 230) for demanding systems

✓ Superior Cutting Action

Knife-edge gate slices through fibrous materials, settled solids, and thick slurries
Self-cleaning design prevents media buildup and jamming
Proven performance in abrasive and corrosive environments

✓ Industrial Reliability

Extended service life with heavy-duty components
Field-proven in harsh industrial environments
Minimal maintenance requirements reduce operational costs

✓ Versatile Installation

Wafer Type: 51mm face-to-face, economical installation
Lug Type: Independent mounting, ideal for dead-end service
Flanged Type: 70mm face-to-face, maximum strength and pressure capability

Technical Specifications

Parameter	Specification
Nominal Size	DN80 (3 inches)
Pressure Rating	PN6/10/16/25, ANSI 150/300/600
Working Pressure	Up to 25 Bar (363 PSI)
Temperature Range	-29°C to +450°C
Cv Value	230 (full open)
Body Materials	WCB, WC6, CF8, CF8M, CF3M, Duplex 2205, Alloy 20
Standards	MSS SP-81, API 6D, ASME B16.5, EN 1092, AWWA C515
End Connections	RF, FF, RTJ, Groove, Weld End

Configuration Options & Dimensions

Wafer Type DN80

Face-to-Face: 51mm
Weight: 18-24 kg
Best For: Cost-effective installations, retrofit applications

Lug Type DN80

Face-to-Face: 51mm
Weight: 22-28 kg
Best For: Dead-end service, easy maintenance access

Flanged Type DN80

Face-to-Face: 70mm
Weight: 28-38 kg
Best For: High pressure, critical industrial applications

Performance Data

Performance Parameter	Value
Maximum Flow Rate (Water)	385 m³/h
Maximum Flow Rate (Slurry)	320 m³/h
Pressure Drop (Full Open)	0.06 Bar
Operating Torque	45-80 Nm
Closing Time (Manual)	20-30 seconds
Cycle Life	20,000+ cycles
Leakage Rate	Zero (Class VI)
Noise Level	<62 dB(A)

Industrial Application Solutions

Mining & Mineral Processing

Tailings and concentrate pipelines
Slurry transport systems
Thickener underflow and overflow
Flotation circuit isolation
Process water and reclaim systems

Pulp & Paper Manufacturing

Stock preparation and cleaning
Pulp transfer and storage systems
White water and filtrate handling
Bleaching and washing circuits
Waste treatment systems

Wastewater Treatment

Primary and secondary clarifiers
Sludge handling and thickening
Biological treatment systems
Chemical feed and dosing
Effluent and discharge systems

Chemical & Petrochemical

Process isolation and control
Catalyst and slurry handling
Reactor feed and discharge
Waste treatment systems
Emergency shutdown applications

Power Generation

Ash handling systems
FGD (Flue Gas Desulfurization)
Cooling water systems
Coal and limestone slurry
Waste treatment applications

Advanced Actuation Systems

Manual Operation

Heavy-Duty Handwheel: Reinforced design for high-torque applications
Gear Drive: Mechanical advantage up to 4:1 reduction
Chainwheel Operation: Ground-level control for elevated installations
Extended Stem: Custom lengths for buried or elevated service

Pneumatic Actuation

Spring Return: Fail-safe positioning for emergency shutdown
Double Acting: Precise positioning with air-to-open/air-to-close
High-Torque Options: Up to 2000 Nm output torque
Smart Positioners: Digital control with HART communication

Electric Actuation

Multi-Turn Motors: Variable speed control with torque limiting
Explosion-Proof: ATEX/IECEx certified for hazardous areas
Position Feedback: 4-20mA, digital, and discrete signals
Remote Operation: SCADA integration and control room interface

Material Engineering

Body Materials

WCB: Carbon steel for general industrial service
WC6 (1.25% Cr): Enhanced temperature and corrosion resistance
CF8 (304 SS): Standard stainless steel for moderate corrosion
CF8M (316 SS): Superior chemical compatibility and corrosion resistance
CF3M (316L SS): Low carbon content for welding applications
Duplex 2205: High strength and excellent corrosion resistance
Alloy 20: Exceptional chemical resistance for severe service

Gate & Seat Technology

Standard Gate: 304/316 SS with polished finish
Hardened Gate: Through-hardened for abrasive service
Stellite Overlay: Cobalt-based alloy for extreme wear resistance
Ceramic Coating: Advanced coating for chemical resistance

Seat Options

Resilient Seats:
- EPDM: Water, chemicals (-20°C to +120°C)
- NBR: Oil resistance (-40°C to +100°C)
- Viton: High temperature, chemicals (-26°C to +200°C)
- HNBR: Enhanced chemical resistance (-40°C to +150°C)
Metal Seats: Stellite 6 overlay for fire-safe and high-temperature service

Quality Assurance & Compliance

Manufacturing Excellence

ISO 9001:2015 Quality Management System
API Q1 Quality management for petroleum industry
PED 2014/68/EU Pressure Equipment Directive compliance
ASME Section VIII Pressure vessel code adherence

Testing & Validation

Pressure Testing: Shell test at 1.5× working pressure
Seat Leakage: Zero leakage per MSS SP-81 Class VI
Torque Testing: Operating and break torque validation
Endurance Testing: 25,000 cycle life verification
Material Testing: PMI, tensile, impact, and hardness testing

Industry Certifications

🔥 API 607/API 6FA – Fire testing certification
⚡ ATEX/IECEx – Explosive atmosphere compliance
🌊 NSF/ANSI 61 – Drinking water system approved
🏭 NACE MR0175 – Sour service environments
📋 ISO 15848 – Fugitive emissions testing
🍎 FDA/3A – Food and pharmaceutical applications

Installation & Maintenance

Installation Specifications

Pipeline Requirements: 6D upstream, 3D downstream straight pipe
Support: Independent valve support required for flanged types
Orientation: Horizontal, vertical, or inclined installation
Access: Minimum 300mm clearance above valve for maintenance

Maintenance Benefits

Top-Entry Design: Service without removing valve from line
Replaceable Components: Seats, packing, and stem seals field-serviceable
Predictive Maintenance: Torque monitoring and position feedback
Extended Intervals: 3-5 year maintenance cycles typical

Service Support

Global Service Network: Authorized service centers in 50+ countries
Emergency Response: 24/7 technical support and rapid deployment
Training Programs: Comprehensive operator and maintenance training
Spare Parts Management: Predictive inventory and fast delivery

Technical Dimensions

Standard Dimensions (PN16)

Type	A (mm)	B (mm)	C (mm)	D (mm)	E (mm)	F (mm)	Weight (kg)
Wafer	51	175	106	121	168	85	20
Lug	51	175	106	121	168	85	25
Flanged	70	175	106	121	168	85	32

Flange Connection Standards

Standard	Bolt Circle	Holes	Bolt Size	Flange OD	Thickness
ANSI 150	127 mm	4 × M19	3/4″	203.2 mm	20.6 mm
ANSI 300	127 mm	4 × M19	3/4″	203.2 mm	28.4 mm
PN16	130 mm	4 × M16	M16	200 mm	20 mm
PN25	130 mm	4 × M16	M16	200 mm	22 mm
JIS 10K	130 mm	4 × M16	M16	190 mm	20 mm

Competitive Advantages

🏗️ Industrial Strength – Heavy-duty construction for continuous operation
⚡ Superior Flow – High Cv rating minimizes system pressure losses
🛡️ Proven Reliability – Extensive field validation in harsh environments
🔧 Easy Maintenance – Field-serviceable design reduces downtime
🌍 Global Support – Comprehensive service network and technical support
📦 Fast Delivery – Standard DN80 configurations available ex-stock
💡 Custom Engineering – Tailored solutions for unique applications

Performance Validation

Field Testing Results

Cycle Life: >25,000 cycles in mining slurry service
Seat Integrity: Zero leakage after 10,000 cycles
Torque Stability: <5% variation over service life
Corrosion Resistance: 316SS exceeds 20-year service life

Application Case Studies

Copper Mine Tailings: 5 years continuous operation, zero failures
Pulp Mill Stock Prep: 15,000 cycles/year, scheduled maintenance only
Wastewater Treatment: 10+ years service with original seats
Chemical Plant: Severe service with custom alloy construction

Get Your DN80 Industrial Solution

Ready to tackle your toughest 3-inch industrial applications? Our engineering team specializes in customizing DN80 knife gate valves for the most demanding process conditions.