1. Technical Specifications

2. Key Features

Fully Vulcanized Disc Lining

The disc core is ductile iron, completely encapsulated by EPDM or NBR rubber through a high-temperature vulcanization process. This creates a seamless, permanent rubber covering over the entire disc surface — not a spray-on coating that can peel or blister. Benefits:

• Complete media isolation: No metal-fluid contact on the disc — superior corrosion protection
• Chemical bond: Rubber-to-metal bond ≥ 6 MPa peel strength — lining will not separate
• Smooth surface: Mold-finished rubber surface equals lower torque, better sealing, reduced friction wear
• Impact resistant: Rubber lining absorbs minor solids impact without damaging the disc body

EPDM vs. NBR Lining — How to Choose

Grooved End Connection — Install 5× Faster

The grooved end eliminates the need for flange bolts, nuts, gaskets, and complex alignment procedures. Each connection uses a single grooved coupling with a C-shape gasket, tightened with two bolts. Advantages over flanged connections:

• Installation speed: Two bolts per coupling versus 4–12 bolts per flange
• No welding: 100% mechanical connection — no hot work permit required
• Alignment tolerance: Couplings allow ±3° angular deflection per joint, absorbing pipe misalignment
• Vibration damping: Rubber gasket in the coupling isolates vibration and reduces noise transmission
• Maintenance access: Remove coupling to take the valve out of line in minutes — no flange spreading
• No flange gaskets: Coupling gasket serves as both seal and connector — one component, not three

Concentric Body Design

• Spherical disc profile machined to exact tolerance for full 360° seat contact
• Self-centering disc ensures consistent seal around the entire circumference
• Low breakaway torque — valve opens smoothly even after prolonged closed position
• Compact face-to-face dimension saves space in equipment rooms and pipe galleries

Blow-Out Proof Stem

The stem features a machined shoulder that prevents it from being ejected under pressure, combined with a double O-ring sealing system for zero external leakage.

3. Material Specification

4. Grooved Coupling Selection

Laux Valve grooved end butterfly valves are compatible with all major grooved coupling brands. The groove profile conforms to AWWA C606 and ISO 4200 standards for roll-grooved and cut-grooved steel pipe connections.

Flexible couplings are also acceptable where pipe movement or thermal expansion accommodation is required. Contact our engineering team for coupling recommendations specific to your piping system.

5. Actuation Options

6.Dimension 



7. Applications

HVAC Systems

The grooved end butterfly valve with EPDM lined disc is the valve of choice for commercial and industrial HVAC systems where grooved piping is standard. Typical locations:

• Chilled water supply and return lines — Bubble-tight isolation prevents thermal bypass, improving system efficiency
• Hot water heating loops — EPDM disc lining rated to 120°C continuous
• Condenser water circuits — Cooling tower isolation, pump suction/discharge
• Air handling unit (AHU) isolation — Quick disconnect via grooved couplings for AHU replacement or coil cleaning
• Chiller isolation — Compact face-to-face ideal for tight equipment room layouts

Water Supply & Distribution

• Potable water mains — EPDM lining is WRAS and NSF/ANSI 61 compliant
• Booster pump stations — Grooved connections absorb pump vibration
• Greywater and rainwater systems — Fully lined disc prevents internal iron corrosion
• Water treatment plants — Filter backwash lines, chemical feed isolation

Fire Protection Piping

Grooved end butterfly valves are widely used in fire protection risers and zone control stations. EPDM lining handles the water quality in sprinkler systems where water may be treated or stagnant. Note: Laux Valve does not hold individual FM or UL certifications for this product range.

Industrial Process

• Compressed air — Suitable for oil-free compressed air (EPDM) or lubricated compressed air (NBR)
• Oil and fuel transfer (NBR) — NBR lined disc for fuel oil, diesel, lubricating oil, hydraulic oil
• Mild chemical service — EPDM for mild acids/alkalis; NBR for hydrocarbons
• Mining and slurry — EPDM lining absorbs solids impact, protects disc body

Marine / Shipboard

• Engine room cooling water
• Ballast and bilge water
• Fresh water generation and distribution
• Sanitary water systems

8. Installation Steps (Grooved End)

Required Tools

• Torque wrench with socket
• Grooved coupling (2 couplings per valve)
• EPDM coupling gaskets (lubricated)
• Pipe end preparation: roll-grooved or cut-grooved to AWWA C606

Procedure

1. Verify the valve is in the fully open position before installation — protects the lined disc from damage
2. Check pipe ends: grooves must be clean, free of burrs, rust, and scale
3. Lubricate coupling gasket with approved lubricant (never use petroleum-based grease on EPDM gaskets)
4. Slip coupling gasket over one pipe end, then position the valve between pipes
5. Slide gasket completely over both pipe ends and valve end, centered on the joint
6. Install coupling halves over gasket, engage both bolt housings
7. Insert bolts and nuts — hand-tighten first
8. Torque bolts evenly in alternating pattern to manufacturer's specification
9. Verify bolt pad gaps are equal on both sides (metal-to-metal contact for rigid couplings)
10. Operate valve full stroke to confirm smooth movement
11. Pressure test the system at 1.1 × operating pressure

Common Mistakes to Avoid

• Installing valve partially closed: Disc protrudes into the flow path and may be damaged by coupling insertion
• Over-torquing coupling bolts: Distorts the coupling and can damage the gasket
• Using petroleum lubricant on EPDM: Degrades the rubber gasket — use only approved silicone or soap-based lubricants
• Skipping the gap check: Uneven coupling pad gaps indicate misalignment and will leak

9. Quality Control & Testing

Every Valve Tested

10. Why Laux Valve Grooved End Butterfly Valves?

• Fully vulcanized disc lining — Not a spray coating; rubber and metal become one piece through the vulcanization process
• Dual lining option — EPDM for water and HVAC; NBR for oil and fuel — one valve platform, two material solutions
• ISO 5211 interface standard — Direct mount any actuator without adapter plates or special brackets
• Grooved end expertise — Groove profile manufactured to AWWA C606, compatible with all major coupling brands worldwide
• 100% tested — Shell, seat, and disc lining test on every valve before shipment
• Short lead times — Standard sizes DN50–DN300 in stock; custom sizes available
• 15+ years export experience — Shipped to 45+ countries worldwide
• OEM/ODM support — Private labeling, custom body colors, custom packaging for project requirements

11. Frequently Asked Questions

Q1: What is the difference between a grooved end and a wafer butterfly valve?

A grooved end butterfly valve has smooth ends with a circumferential groove that accepts a grooved coupling for connection to grooved pipe. A wafer butterfly valve is clamped between two pipe flanges. Grooved end valves install faster (two bolts per coupling versus multiple flange bolts) and are preferred for HVAC, fire protection, and water systems that use grooved piping as their standard connection method.

Q2: Can the lined disc be damaged during installation?

The disc should be in the fully open position during installation. Following this instruction, the grooved coupling slides over the valve end and pipe end without contacting the disc. The vulcanized lining is mechanically bonded — it will not peel from edge impact during normal installation. The rubber lining can absorb minor contact without damage.

Q3: Should I choose EPDM or NBR disc lining?

Choose EPDM for water, hot water, steam condensate, mild chemicals, and HVAC applications. Choose NBR for oils, fuels, lubricants, and compressed air with oil carryover. If in doubt, email our applications team with your medium, temperature, and pressure — we will recommend the correct material.

Q4: Are grooved end butterfly valves suitable for vacuum service?

Grooved end connections are generally not recommended for full vacuum service because the coupling gasket relies on positive pressure to seal. For vacuum applications, consider our double flange butterfly valve with EPDM vulcanized seat.

Q5: Do you provide the grooved couplings with the valve?

We can supply couplings as part of a complete valve package upon request. Standard supply is the valve only with grooved end preparation. Couplings can be sourced separately from any grooved coupling manufacturer.

Q6: Can the valve be automated with an electric or pneumatic actuator?

Yes. All sizes from DN50 to DN300 feature an ISO 5211 top mounting pad as standard. The valve can be fitted with electric actuators, pneumatic actuators, or a worm gearbox without modification.

Q7: What is the lead time?

Standard sizes DN50–DN300 with EPDM lining: 1–3 working days in stock. NBR lining or custom configurations: 5–10 working days. Large quantities: contact us for a production schedule.

Contact Laux Valve for a quotation on grooved end butterfly valves. Please advise size, pressure rating, lining material (EPDM or NBR), and actuation preference (lever, gearbox, pneumatic, or electric).

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.