Product Overview

The Laux Valve electric actuated lug type split body butterfly valve with full PTFE lining is a complete valve-actuator assembly designed for automated flow control of highly corrosive chemicals, acids, caustics, solvents, and high-purity media. The valve features a unique split body design that allows the PTFE liner to be fully encapsulated between two body halves, creating a seamless, continuous fluoropolymer lining with no body metal exposed to the process media.

The lug type body pattern provides independent bolting on each side, enabling dead-end isolation and independent pipe removal — essential for chemical process maintenance. The factory-mounted electric actuator provides reliable on-off or modulating control with 4-20 mA position feedback.

Key Features

• Full PTFE/PFA Lining – The entire valve interior (body bore, flange faces, and stem bore) is lined with a continuous, seamless PTFE or PFA layer. The lining thickness is typically 3-6 mm depending on size. The fluoropolymer lining provides near-universal chemical resistance — handling virtually all acids (including HCl, H₂SO₄, HNO₃, HF), caustics, solvents, chlorides, and aggressive chemical intermediates.
• Split Body Design – The valve body is manufactured in two halves that bolt together, encapsulating the PTFE liner with no exposed metal in the flow path. The split body allows the PTFE liner to be molded with full encapsulation, eliminating the pinch points and stress concentrations found in one-piece lined bodies.
• Lug Type Body Pattern – Threaded lug inserts on both flange faces provide independent bolting. The valve can be installed for dead-end service at tank outlets, pump discharges, and pipe terminations. Downstream piping can be removed while the valve remains bolted to the upstream pipe.
• Electric Actuator (Factory Mounted) – Heavy-duty electric actuator with ISO 5211 direct mount. Available in on-off (open/close) or modulating (4-20 mA proportional control) configurations. Manual handwheel override standard for maintenance and emergency operation.
• Field-Replaceable Liner – The PTFE liner can be replaced in the field. The split body is unbolted, the old liner removed, and a new liner installed between the two body halves. No specialized tooling or factory service required.
• Bi-Directional Bubble-Tight Shut-Off – The PTFE lining forms the seat surface against the PTFE-coated or stainless steel disc. The resilient backing (elastomer or expandable PTFE) provides the compressive force for bubble-tight sealing.
• Vacuum Rated – The full encapsulation liner design is rated for full vacuum service to -1 bar (-14.7 psi), unlike standard PTFE sleeve designs that may collapse under vacuum.
• Integral Flange Gaskets – The PTFE lining extends to form integral sealing surfaces on both flange faces. No separate flange gaskets are required in most installations.
• 100% Factory Tested – Every valve undergoes shell hydrostatic test, seat leakage test, and high-voltage spark test (holiday detection) on the PTFE lining. The complete electric actuator assembly is stroke-tested and position-calibrated before shipment.

Split Body & Full PTFE Lining – Design Detail

Split Body Construction

• The valve body is cast or fabricated in two symmetrical halves (left and right)
• Each half has precision-machined mating faces with a tongue-and-groove or rabbet joint for alignment
• The PTFE liner is compression-molded as a complete sleeve that nests between the two body halves
• When the body bolts are torqued, the PTFE liner is compressed at the flange faces, creating a leak-free seal that isolates the body metal from the media
• The split body can be unbolted for liner replacement without removing the valve from the pipeline

PTFE/PFA Liner Construction

• PTFE (Polytetrafluoroethylene): Standard lining material. Operating range -20°C to +200°C. Suitable for 95%+ of chemical services. Lower cost than PFA.
• PFA (Perfluoroalkoxy): Enhanced performance. Operating range -20°C to +260°C. Higher purity than PTFE. Better anti-stick properties. Recommended for high-purity, pharmaceutical, and semiconductor applications.
• Lining thickness: 3-6 mm depending on valve size, applied via compression molding or isostatic molding
• Spark tested: 100% high-voltage holiday detection (15-20 kV/mm) to verify pinhole-free lining

Valve Specifications

Electric Actuator Specifications

Chemical Resistance Guide – PTFE Lined Valve

Applications

• Chemical Processing – Acid and caustic transfer, chemical reactor feed, storage tank isolation, chemical unloading stations. The PTFE lining handles virtually all chemicals that would destroy standard elastomer-seated valves.
• Pharmaceutical & Fine Chemical – High-purity chemical handling, API synthesis, solvent recovery. PFA lining option for ultrapure applications requiring low extractables and smooth non-stick surfaces.
• Metal Finishing & Plating – Chrome plating baths, acid pickling lines, caustic cleaning solutions. The PTFE lining withstands the aggressive chemical mixtures used in surface treatment.
• Fertilizer Production – Phosphoric acid, sulfuric acid, ammonia solutions, and fertilizer intermediates at elevated temperatures.
• Wastewater Treatment & Industrial Effluent – Chemical waste neutralization systems, industrial effluent treatment where aggressive chemicals are present.
• Pulp & Paper – Bleach chemical lines (chlorine dioxide, sodium hypochlorite, hydrogen peroxide), white liquor, green liquor handling.

Frequently Asked Questions

What is a split body PTFE lined butterfly valve?

A split body PTFE lined butterfly valve has a two-piece (split) body design that encapsulates a full PTFE or PFA liner. The split body construction allows the fluoropolymer liner to be completely molded around the flow path with no exposed metal, providing universal chemical resistance. The lug type body pattern allows dead-end installation.

What is the difference between PTFE lined and PTFE coated disc?

The body lining is a thick (3-6 mm) PTFE sleeve that lines the entire valve body interior, protecting the metal body from chemical attack. The disc coating is a thinner PTFE or PFA layer applied to the disc surface to provide chemical resistance for the disc. In a fully lined valve, both the body and disc are protected with PTFE, ensuring no metal contact with the process media.

Can the PTFE liner be replaced in the field?

Yes. The split body design allows the two body halves to be unbolted and separated. The old PTFE liner is removed and a new liner is installed between the body halves. The valve body remains in the pipeline. Replacement typically takes 30-60 minutes.

What temperature can a PTFE lined butterfly valve handle?

Standard PTFE lining: -20°C to +200°C (-4°F to +392°F). PFA lining: -20°C to +260°C (-4°F to +500°F). Pressure rating must be derated at elevated temperatures per the manufacturer's pressure-temperature chart.

Is this valve suitable for vacuum service?

Yes. The full encapsulation liner design in a split body valve is rated for full vacuum to -1 bar (-14.7 psi). Unlike PTFE sleeve or drop-in liner designs that may collapse under vacuum, the split body fully encapsulates the PTFE, preventing liner collapse.

What is the maximum size available?

Split body PTFE lined butterfly valves are commonly available from 2" (DN50) to 24" (DN600). 

Ordering Information

To order, please specify: valve size, body material, lining material (PTFE/PFA), disc material, actuator voltage and control type, and any hazardous area certification requirements.

Email: james@lauxvalve.com | Tel: +86 18920833829 | Website: lauxvalve.com

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.