• Vulcanized Rubber Seat – The EPDM or NBR rubber lining is chemically and mechanically bonded to the ductile iron body through a high-temperature vulcanization process. Unlike cartridge or liner seats, the vulcanized seat cannot shift, extrude, or blow out under pressure — providing permanent, maintenance-free bubble-tight sealing.
• Double Flange Configuration – Flanged connections on both sides (drilled to ASME B16.5 Class 150/300 or EN 1092-2 PN10/PN16) provide rigid, gasket-free installation. The valve can be installed at the end of a pipe run for dead-end isolation without requiring a blank flange.
• Bi-Directional Sealing – The vulcanized seat design achieves bubble-tight shut-off in both flow directions at full rated pressure, eliminating the need for flow direction arrows and simplifying installation.
• Dead-End Service Rated – The double flange body and bonded seat allow the valve to hold full rated pressure from one side (dead-end) — critical for pump discharge isolation, tank outlet control, and maintenance isolation at pipe terminations.
• Ductile Iron Construction – Body and disc manufactured from ASTM A536 Grade 65-45-12 ductile iron, offering superior strength and impact resistance compared to cast iron. Fusion-bonded epoxy coating (min 250 microns) provides long-term corrosion protection.
• Blowout-Proof Stem Design – One-piece stem with internal retaining ring and thrust washer prevents stem ejection under pressure. Stem seals are field-replaceable without valve disassembly.
• ISO 5211 Mounting Pad – Standardized mounting interface enables direct installation of pneumatic actuators, electric actuators, or gear operators without adapter brackets.
• Full Compliance – Designed and tested per AWWA C504, EN 593, API 609, and ISO 10631 standards.

Technical Specifications

Vulcanized Seat vs. Cartridge Seat – Why Bonded Matters

Detailed Applications

1. Municipal Water Distribution

The double flange vulcanized seat valve is widely specified in city water networks for its reliability and dead-end capability:

• Mainline isolation – Sectionalizes water mains (4"–24") for repair and replacement without disrupting the entire distribution network. The double flange connection allows direct bolting to existing flanged fittings.
• Fire hydrant branch control – Installed at hydrant lateral take-offs for individual hydrant isolation during maintenance.
• Pressure zone separation – Used at pressure zone boundaries to isolate PRV stations and booster pump connections.
• Water treatment plant piping – Raw water inlet, settled water, filtered water, and finished water mains within treatment facilities.

2. Wastewater Treatment

• Plant inlet isolation – Provides positive shut-off at the treatment plant headworks. The vulcanized EPDM seat resists hydrogen sulfide corrosion.
• Digester gas and sludge lines – Controls flow in sludge recirculation and digestion systems. Viton seat option available for aggressive biogas applications.
• Aeration and blower control – Installed on air supply lines to aeration basins. Full bore design minimizes pressure drop.
• Effluent discharge – Controls treated effluent flow to outfall or reclaimed water distribution.

3. HVAC and Chilled Water Systems

• Chiller isolation – Supply and return isolation for individual chillers in central plant configurations.
• Cooling tower control – Flow control to cooling tower inlet and outlet headers, including seasonal isolation.
• District cooling networks – Building entrance isolation in district cooling systems with PN16/Class 150 flanged connections.

4. Fire Protection Systems

• Fire pump suction – The dead-end rated double flange valve is ideal for fire pump suction isolation where full pump suction pressure must be held from one side.
• Fire main sectional control – Underground fire loop isolation in valve pits.
• Standpipe and sprinkler risers – Main riser isolation valves in commercial and industrial buildings.

5. Industrial Process Water

• Cooling water circuits – Heat exchanger and condenser isolation in power plants, refineries, and chemical plants.
• Raw water intake – Control of surface water or groundwater intake flow.
• Utility water systems – General plant service water isolation for washing, dust suppression, and equipment cooling.

6. Pump Station and Pipeline

• Pump discharge isolation – Double flange dead-end rating allows individual pump discharge isolation for maintenance. Critical for multi-pump stations where one pump is serviced while others remain online.
• Check valve bypass – Isolation around check valves for inspection and repair.
• Transmission main sectionalizing – Long-distance pipeline isolation at valve stations every 1–5 km.

7. Water Storage Tanks and Reservoirs

• Tank inlet/outlet – Dead-end rated valve installed directly on tank outlet nozzles.
• Altitude valve isolation – Bypass and isolation for altitude control valves.
• Overflow and drain lines – Reservoir overflow control and tank drain isolation.

Available Options

Why Choose Laux Valve Double Flange Butterfly Valve?

• True dead-end service – Vulcanized seat + double flange design provides full-pressure dead-end capability, unlike cartridge seat valves that require derating
• 20+ year seat life – Chemically bonded rubber seat eliminates the failure modes of mechanically retained seats
• Bi-directional bubble-tight shut-off – No flow direction restrictions, simplified installation
• Automation ready – ISO 5211 mounting pad for easy actuator integration
• Global compliance – AWWA C504, EN 593, NSF 61, WRAS, CE – one valve for worldwide projects
• Factory tested – 100% hydrostatic shell and seat leakage test per API 598
• Short lead times – Stocked components for sizes 4"–24" Class 150

Butterfly Valve Manufacturing Process
From Technical Confirmation to Final Delivery



Standardized Quality Control Process

From raw material inspection to final delivery, every butterfly valve undergoes a comprehensive quality inspection to ensure reliable performance and compliance with international standards.

International Certifications

Manufactured to international quality standards and certified for global industrial and potable water applications.