Product Overview
The Elastic Seated Gate Valve features an elastomer-encapsulated wedge to deliver drop-tight isolation in liquid pipelines. Designed as a modern alternative to metal-seated valves, its resilient wedge deforms slightly under closing torque to compensate for internal seat tolerances, achieving zero-leakage shut-off.
Optimized for drinking water networks, treatment plants, and industrial utility lines, this full-bore valve minimizes head loss and operating torque. It accommodates handwheels, buried service operating caps, spur gearboxes, or electric actuators for localized or automated control.
Advantages of Elastic Seated Gate Valve
Resilient Seated Wedge
Full elastomer encapsulation provides dynamic sealing compensation against the body seats, maintaining drop-tight performance across pressure differentials.
Full-Bore Passage
The wedge retracts completely out of the flow path when open, minimizing friction losses and pressure drops.
Sediment-Free Cavity
A smooth, unobstructed bottom passage prevents debris buildup and seat degradation in raw water lines.
Protective Epoxy Coating
Thermally bonded, non-toxic epoxy coating protects internal and external cast surfaces against corrosion and tuberculation.
Versatile Actuation Options
Standardized stem flanges allow direct mounting of manual handwheels, underground extension spindles, gearboxes, or multi-turn actuators.
Low-Maintenance Isolation
Durable construction and self-cleaning seating geometry extend service intervals during pipeline maintenance and system commissioning.
Working Principle
The valve operates via a vertical wedge driven by a threaded stainless steel stem assembly.
Rotating the drive counter-clockwise raises the encapsulated wedge out of the waterway, presenting a straight-through bore with minimal fluid resistance. Rotating clockwise drives the wedge into the bottom cavity, where the compressed elastomeric surface seals tightly against the inner body walls to block bidirectional flow.
Technical Specifications
|
Feature / Parameter |
Standard Value |
|
Size Range |
DN40 – DN600 |
|
Nominal Pressure |
PN10 / PN16 / Class 150 |
|
Body Material |
Ductile Iron (EN-GJS-500-7 / GGG50) |
|
Wedge Material |
Ductile Iron fully encapsulated with EPDM / NBR |
|
Stem Material |
Stainless Steel (AISI 420 / 304 / 316) |
|
Sealing Material |
EPDM (Drinking Water) / NBR (Sewage & Oil) |
|
Connection / Drilling |
Flanged (EN 1092-2 / ANSI B16.5 / BS 4504) |
|
Face-to-Face |
BS 5163 / DIN 3202 F4 / EN 558 Series 14 |
|
Pressure Testing |
EN 12266-1 / ISO 5208 |
|
Surface Coating |
Fusion Bonded Epoxy (FBE) >= 250 microns |
Main Components & Material Selection
|
No. |
Component |
Material Options |
Primary Function |
|
1 |
Body |
Ductile Iron EN-GJS-500-7 |
Pressure-retaining main enclosure |
|
2 |
Bonnet |
Ductile Iron EN-GJS-500-7 |
Seals body cavity and houses stem seals |
|
3 |
Wedge |
Ductile Iron + EPDM / NBR |
Forms primary fluid barrier |
|
4 |
Stem |
Stainless Steel 420 / 304 / 316 |
Drives vertical wedge displacement |
|
5 |
Stem Packing |
EPDM / NBR O-Rings |
Prevents fluid leakage along the stem |
|
6 |
Thrust Collar |
High-Grade Brass / Bronze |
Absorbs axial operating forces |
|
7 |
Drive Interface |
Ductile Iron / Carbon Steel |
Interface for handwheel or actuator |
|
8 |
Body Fasteners |
Stainless Steel 304 / Grade 8.8 |
Secures bonnet assembly to main body |
Available Configurations
Stem Design
• Non-Rising Stem (NRS): Compact layout designed for underground pits and space-constrained vaults.
• Rising Stem (OS&Y): Extends externally during opening to provide immediate visual confirmation of valve position.
Drive Options
• Manual Handwheel
• Square Operating Cap for subterranean T-key access
• Bevel / Spur Gearbox
• Electric Multi-Turn Actuator
End Connections
Standard Flanged Ends conforming to EN, ANSI, or BS standards.
Elastomer Formulations
• EPDM: WRAS-compliant compound for drinking water up to 120 C.
• NBR: Formulated for raw water, sewage, and hydrocarbon-traced media.
Surface Coating
Electrostatic Fusion Bonded Epoxy (FBE) for harsh soil or immersion environments.
Typical Applications
Municipal Water Mains
Provides main line isolation across city potable water networks.
Water Treatment Plants
Manages flow isolation around filtration units, pumps, and chemical dosing stations.
Wastewater Networks
Handles raw sewage, treated effluent, and industrial sludge systems without clogging.
Commercial Building Services
Controls water distribution risers and isolation zones in commercial developments.
Agricultural Irrigation
Protects main delivery lines and sub-distribution channels in large-scale farming networks.
Industrial Utility Piping
Manages secondary cooling lines, fire protection loops, and process utility water.
Quality Assurance & Factory Testing
Dimensional Verification: Full check of flange face-to-face dimensions, bolt hole layouts, and wall thickness.
Material Spectrometry: Chemical analysis and tensile testing for all iron and stainless steel castings.
Shell Pressure Test: Hydrostatic shell testing at 1.5 times nominal pressure to confirm structural integrity.
Seat Leakage Test: Bi-directional seat closure testing at 1.1 times nominal pressure to verify zero leakage.
Coating Inspection: Spark testing (holiday detection) and thickness measurement on epoxy-coated surfaces.
Documentation: Material test certificates, pressure test records, and certificates of compliance provided with every shipment.
Installation & Operational Guidelines
Line Flushing
Clear pipe interiors of welding slag, sand, and debris before installation.
Flange Alignment
Ensure companion flanges are parallel and concentric; avoid forcing misaligned pipe joints together using bolt torque.
Cross-Tightening
Torque flange bolts evenly in a star pattern using calibrated wrenches.
Underground Mounting:
Center valve box extensions precisely over the square operating cap to avoid bending loads on the stem.
Smooth Operation
Operate handwheels manually without using pipe extensions or external leverage tools.
Chemical Compatibility
Verify that pipe flushing chemicals used during commissioning are compatible with the selected EPDM/NBR seals.
FAQ
Q: What is an Elastic Seated Gate Valve?
A: An Elastic Seated Gate Valve uses an elastomer-covered wedge as its sealing element. When closed, the resilient material deforms slightly under stem force to form a drop-tight seal against the interior iron body.
Q: How does a resilient seated gate valve differ from a metal seated gate valve?
A: Resilient seated valves use an elastomer coating (EPDM/NBR) on the wedge for complete zero-leakage shut-off at lower operating torque. Metal seated valves utilize brass or stainless steel seating rings, making them better suited for high-temperature service or heavy abrasive slurry where rubber coatings would wear down.
Q: Can an Elastic Seated Gate Valve be used for flow regulation or throttling?
A: No. Gate valves must operate fully open or fully closed. Keeping the wedge partially open exposes the resilient coating to high-velocity fluid turbulence, leading to premature erosion and loss of sealing ability.
Q: Should EPDM or NBR elastomer be selected for the wedge coating?
A: EPDM is ideal for potable water, raw water, and non-viscous neutral media up to 120 C. NBR is recommended for fluids containing oils, hydrocarbons, or industrial wastewater streams.
Q: What information is required to receive an accurate technical quotation?
A: Provide the required size (DN), working pressure (PN/Class), flange drilling standard, actuation method, fluid medium, operating temperature range, and required order quantity.
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