CPVC Butterfly Valve — Wafer Type, Viton Seat, up to 95 °C, ISO 5211

The CPVC butterfly valve with Viton seat covers the temperature range that conventional PVC butterfly valves cannot handle: with an operating temperature of 0 °C to 95 °C — almost double the limit of standard PVC (50 °C) — it is the right solution for hot water, low-temperature steam condensate, warm process fluids, and domestic hot water distribution systems where PVC would deform or fail due to thermal fatigue within weeks. The CPVC (Chlorinated Polyvinyl Chloride) body and disc maintain the polymer's mechanical and chemical resistance at temperatures where standard PVC is no longer viable, combined with a Viton (FKM) seat that complements the chemical resistance for fluids that would degrade EPDM.

Wafer design — for installation between ANSI 150, DIN, or JIS flanges. Leverless: factory-prepared for direct mounting of pneumatic or electric actuators with an ISO 5211 mount. All diameters available in stock.

CPVC vs. PVC — the difference that justifies this product

CPVC (Chlorinated Polyvinyl Chloride) is standard PVC subjected to an additional chlorination process that increases the polymer's chlorine content from 56% to 67%. This process modifies the molecular structure of the polymer in two aspects critical for industrial applications:

• Higher heat deflection temperature: Standard PVC begins to soften and lose mechanical strength above 55–60 °C. CPVC maintains its structural rigidity up to 90–100 °C — a direct result of the increased molecular cross-link density generated by the additional chlorination. For a butterfly valve under 150 psi pressure, this difference determines whether the valve deforms in service or maintains its shape and seat sealing.
• Greater chemical resistance: The higher chlorine density in the CPVC chain makes it more resistant to some acids, alkalis, and organic fluids that would attack standard PVC. For fluids that are at the compatibility limit of PVC, CPVC often offers the necessary additional compatibility.

Why CPVC outperforms PVC in butterfly valves:

The Viton seat — why not EPDM in this valve

The CPVC + Viton combination is not accidental — it is optimized for the range of applications where CPVC is necessary:

• Temperature: Viton (FKM) withstands service temperatures up to 200 °C — well above the CPVC limit. The Viton seat is never the limiting temperature factor in this valve; the CPVC body always defines the limit at 95 °C.
• Chemical resistance: Viton resists fluids that most often require CPVC instead of PVC — diluted acids at moderate temperatures, solutions with agrochemicals, process fluids with traces of organic solvents. EPDM would not be compatible with several of these fluids.
• Hot water with chemical treatment: Domestic hot water systems and heating circuits with corrosion inhibitors require a seat that resists both temperature and chemical additives — Viton covers both requirements better than EPDM.

Wafer design — installation between flanges

The valve is installed compressed between the two pipe flanges, held by the through-bolts of the flanges. The body holes are through-holes without threads — they require both flanges to be present to hold the valve in position. Compatible with flanges:

• ANSI 150
• DIN PN10 / PN16
• JIS 10K

For installations where one side of the pipe needs to be disconnected while maintaining pressure on the other (dead-end service), the lug version with threaded holes is the correct choice — inquire about availability.

Actuator-ready — leverless from factory

This valve is supplied without a manual lever, with the ISO 5211 mount exposed and ready for direct actuator mounting. This is the correct configuration when the end use is always automated — the cost of the manual lever, which would be removed when mounting the actuator, is not wasted. For occasional manual operation, the lever can be purchased separately.

• Single or double-acting pneumatic actuator: For isolation sequences and frequent opening in automated systems. The NC single-acting is the standard safety configuration for process fluids. See butterfly valves with pneumatic actuator →
• ON/OFF or modulating electric actuator: For systems without a compressed air network, PLC control, or integration with BMS. See butterfly valves with electric actuator →

Technical specifications

• Type: Wafer butterfly valve — between flanges, through-holes without threads
• Body material: CPVC (Chlorinated Polyvinyl Chloride)
• Disc material: CPVC
• Seat: Viton (FKM)
• Stem: Stainless steel SS304
• Actuator mount: ISO 5211 — leverless from factory
• Flange compatibility: ANSI 150, DIN PN10/PN16, JIS 10K
• Working pressure: 150 psi (10.3 bar) at ambient temperature
• Working temperature: 0 °C to 95 °C
• Bidirectional operation: Yes

Chemical compatibility — CPVC + Viton

• ✅ Domestic hot water up to 95 °C
• ✅ Hot process water without high chlorides
• ✅ Sulfuric acid H₂SO₄ up to 25% at ambient temperature
• ✅ Hydrochloric acid HCl up to 20%
• ✅ Salt solutions, fertilizers with agrochemicals
• ✅ Vegetable oils and light oils
• ✅ Sodium hypochlorite up to 15%
• ✅ Seawater at moderate temperatures
• ⚠️ Ketones and esters: not compatible with Viton
• ⚠️ H₂SO₄ >50% or concentrated HCl at elevated temperature: use anti-corrosion butterfly valve with PTFE liner
• ❌ Steam above 100 °C: use metallic butterfly valve

Main applications

• Domestic hot water (DHW) — 60 to 95 °C: The most frequent application of CPVC butterfly valves in Mexico. Hot water installations in hospitals, hotels, shopping centers, and apartment buildings require valves that continuously withstand 60–80 °C — a temperature that would destroy a standard PVC butterfly valve in weeks. CPVC is the industry standard material for DHW pipes and valves in thermoplastic polymer.
• Chemical industry — corrosive fluids at moderate temperatures: Diluted acids, moderate alkalis, and process solutions between 50 and 90 °C where standard PVC is not viable due to temperature, and stainless steel is excessively costly. CPVC covers this specific range with the lowest cost of the entire range.
• Irrigation systems with hot or solar water: Irrigation installations with water heated by solar collectors that can reach 60–80 °C in summer. PVC valves in these installations are the most frequent point of failure in summer when water reaches extreme temperatures.
• Water treatment — reagents at elevated temperatures: Dosing of process reagents at 50–80 °C in treatment plants. CPVC + Viton covers the chemical compatibility of the most frequent reagents at process temperatures where PVC is no longer sufficient.
• Low-pressure steam condensate (<95 °C): Low-pressure steam condensate exits at temperatures of 80–95 °C — above the PVC limit but within the CPVC range. For condensate return in installations with plastic pipes, the CPVC butterfly valve is the correct solution.
• Pools with hot water and spa: Hot tubs, spas, and heated pools where the water is maintained at 38–45 °C with chemical treatment. CPVC + Viton resists both the temperature and the water treatment products.
• Food industry — hot process water: Distribution of hot cleaning water (simplified CIP) and blanching in plants where the water temperature exceeds the standard PVC limit and a material that does not contaminate the product is required.

For the complete range of plastic butterfly valves, see PVC and CPVC butterfly valves category →