Views: 0 Author: Site Editor Publish Time: 11-01-2026 Origin: Site
The global market for corrosion-resistant butterfly valves continues to grow, driven by demand from chemical processing, pharmaceutical manufacturing, and water treatment industries. Behind that growth is a simple reality: facilities are handling more aggressive media than ever before. Standard elastomer-seated valves — EPDM, NBR, or even Viton — simply cannot withstand the combination of strong acids, oxidizers, and high temperatures found in modern process lines.
That’s where PTFE lined butterfly valves come in. And for larger pipe sizes, an 8-inch double flanged configuration is one of the most practical solutions available.
EPDM and NBR seats work well for water, wastewater, and mild chemical service. But expose them to concentrated sulfuric acid, hydrochloric acid, or sodium hypochlorite, and they degrade quickly — swelling, cracking, or losing their sealing elasticity. The result is leaks, frequent maintenance, and unplanned downtime.
PTFE (polytetrafluoroethylene) solves this problem. It is chemically inert across a pH range of 0–14, resists virtually all industrial chemicals, and maintains sealing performance from -29°C to +160°C (short-term up to +200°C). Compared to elastomer seats, PTFE offers significantly longer service life in aggressive media.
In a standard butterfly valve, both the body bore and the disc are metal components exposed directly to the flow. In corrosive service, this means they become failure points — corroding, pitting, or contaminating the process media.
This 8-inch valve is fully lined with PTFE. The flange sealing faces, and the stainless steel disc are all covered with a continuous PTFE layer. The stainless steel core of the disc provides mechanical strength, while the PTFE encapsulation fully isolates the metal from the process fluid. No metal contact, no corrosion, no contamination.
The PTFE lining creates a smooth, non-stick surface that reduces friction and prevents media adhesion — an important consideration in pharmaceutical and food-grade applications where product purity is critical.
Two design choices make this valve particularly suited for large-diameter corrosive service:
Double flanged connection. The valve bolts directly to pipeline flanges on both ends, providing a rigid, self-supporting connection. Unlike wafer valves that rely on adjacent flanges for support, the double flanged body carries pipe loads independently — important in long runs and vibrating systems.
Split body construction. The body splits into two halves, allowing direct access to the seat and disc without removing the valve from the pipeline. When the PTFE lining or seat eventually wears — and it will, after enough cycles — the replacement takes minutes, not hours. This design significantly reduces downtime compared to one-piece body valves.
Parameter | Specification |
Valve Type | PTFE Lined Butterfly Valve – Double Flanged, Split Body |
Size | 8 Inch (DN50-DN900) |
Body Material | Ductile Iron A536 65-45-12 (GGG40) |
Lining Material | PTFE |
Disc Material | PTFE Encapsulated Stainless Steel Disc |
Seat Material | PTFE |
Body Design | Two-piece split body |
Connection | Double Flanged |
Pressure Rating | PN10 / PN16 (standard) |
Top Flange | ISO 5211 |
Design Standard | EN 593 / API 609 |
Testing Standard | API 598 / EN 12266-1 |
PTFE lined butterfly valves with double flanged, split body construction are widely used in:
Chemical processing — sulfuric acid, hydrochloric acid, chlorine gas, solvents
Pharmaceutical manufacturing — high-purity processes, CIP/SIP systems
Desalination and seawater systems — brine transfer, seawater intake
Water treatment — chemical dosing, ozone, sodium hypochlorite
Pulp and paper — bleaching chemicals, corrosive liquors
Petrochemical — refining, process lines with aggressive media
For a deeper look at how material selection affects butterfly valve performance in water and wastewater systems, see our 18-inch wafer butterfly valve material selection guide.
Can the PTFE lining or seat be replaced without removing the valve?
Yes. The split body design allows you to separate the two halves, replace the PTFE seat or lining components, and reassemble while the valve remains bolted in the pipeline.
What media is PTFE NOT suitable for?
PTFE is resistant to virtually all industrial chemicals, but it is not recommended for molten alkali metals (such as molten sodium) or elemental fluorine at elevated temperatures.
What actuation options are available?
The ISO 5211 top flange accepts hand lever, gear operator, electric actuator, pneumatic actuator, or hydraulic actuator.
Do you offer other sizes?
Yes. We manufacture PTFE lined butterfly valves from DN50 to DN1200, with custom materials, pressure ratings, and flange standards available on request.
Tianjin Worlds Valve Co., Ltd. is a direct OEM/ODM manufacturer with over 19 years of export experience. We hold ISO 9001:2015 certification (audited by LRQA) and manufacture butterfly valves in wafer, lug, double flanged, grooved end, and U-section configurations. Our PTFE lined and PTFE seated valves serve chemical, pharmaceutical, desalination, and industrial customers in more than 50 countries.
For this 8-inch PTFE lined double flanged butterfly valve, we can customize materials, pressure ratings, flange standards, coatings, and actuation to your exact requirements. Our engineering team uses SolidWorks, Pro/E, and AutoCAD to review and prepare drawings for approval before production.
Contact us to discuss your project — we’ll respond within 24 hours with a tailored solution and quotation.
