Fully Lined EPDM Rubber Lug Butterfly Valve Handle Operated

The fully lined EPDM rubber lug butterfly valve is a corrosion-resistant isolation valve designed for municipal sewage networks, wastewater treatment plants, irrigation headers and low-corrosivity industrial water lines where elastomeric full-lining provides superior protection against permeation and galvanic attack. Manufactured by Trekre Valve at our Wuxi facility, this lug-type butterfly valve features an EPDM-lined body bore and EPDM-coated disc that isolate the fluid from all wetted cast iron or ductile iron surfaces. Handle lever operation is supplied for quick local shut-off on smaller nominal sizes, with worm gear, pneumatic or electric actuators available when operating torque or remote control is required.

Full EPDM rubber lining differs from partial resilient seat designs by encapsulating the entire valve flow path, including the body interior, disc faces and lug connection zones exposed to the medium. EPDM (ethylene propylene diene monomer) offers excellent resistance to dilute acids, alkalis, oxidizing biocides and aqueous slurries at temperatures typically up to 120 °C in continuous service. Compared with PTFE or PFA fluoropolymer linings, EPDM-lined lug butterfly valves deliver a cost-effective solution for water, sewage and HVAC applications where fluoropolymer chemical resistance is not mandatory but long-term elastomer integrity against biofilm growth and abrasive suspended solids remains essential.

Fully lined EPDM lug butterfly valve construction

Connection type: lug type (semi-lug) butterfly valve; compatible with ANSI Class 150, JIS 10K, EN PN10/PN16 and DIN flange patterns via through-bolts between pipe flanges

Structure: concentric or double-offset disc on a one-piece stem; fully molded EPDM lining bonded to ductile iron or cast iron body

Sealing form: full EPDM rubber lining on body bore and disc; resilient seated shut-off with bubble-tight closure on water and air at rated pressure

Operation: handle lever (manual) as standard; optional worm gear box, pneumatic actuator or electric actuator with ISO 5211 mounting pad

Body material: ductile iron GGG40/GGG50 or cast iron GG25 with full EPDM lining

Disc material: ductile iron or stainless steel disc with EPDM coating; fully lined EPDM disc option for maximum corrosion barrier

Seat / lining: EPDM rubber (NBR, VITON or SI lining available on request for specific media compatibility)

Nominal size and pressure rating

Nominal diameter range: DN50 (2 inch) through DN1200 (48 inch) depending on flange standard and actuator selection. Pressure class: ANSI Class 150, JIS 10K, EN PN10 and PN16 as standard. Higher pressure ratings including PN25 and ANSI Class 300 can be evaluated for specific size and temperature combinations. Face-to-face dimensions follow EN 558 Series 20, ISO 5752 or manufacturer standard tables aligned with the nominated flange specification. For one-sided pipeline maintenance, confirm the documented single-flange rating, permitted pressure direction, bolting arrangement and isolation procedure for the exact valve model and size. Lug-type drilling alone does not establish permission to remove downstream piping.

Drive methods and actuation options

Handle lever operation suits valves up to approximately DN200 where seating torque remains manageable for field operators. The handle includes a positive stop at fully open and fully closed positions and can be locked in the closed position with a padlock bracket on request. For larger sizes or buried service, a worm gear manual operator reduces input torque and provides a visual position indicator. Pneumatic double-acting or spring-return actuators enable automated on/off control in SCADA-managed water plants. Electric actuators with 4–20 mA modulating control are available for proportional flow regulation in balancing applications. All actuators mount to an ISO 5211 top flange integrated into the valve body design.

Applicable working conditions and industries

This EPDM fully lined lug butterfly valve is specified for clean water, raw water intake, secondary sewage, sludge recirculation, cooling water circuits, fire protection ring mains and HVAC chilled water systems. EPDM lining resists ozone, sunlight and chloramine disinfection better than NBR, making it suitable for outdoor exposed installations and potable water networks where NSF/WRAS material compliance may be requested. The valve is not recommended for concentrated hydrocarbon solvents, aromatic oils or strong oxidizing acids where PTFE-lined alternatives should be selected instead. Typical design temperature range: −10 °C to +120 °C for EPDM; verify thermal cycling when used on steam condensate return or hot water loops above 90 °C.

Product parameters

Valve type: fully lined EPDM rubber lug butterfly valve

Model reference: D371X-16Q / D371J-10Q (project-specific)

Size range: DN50–DN1200 (2″–48″)

Pressure rating: PN10, PN16 / ANSI 150 / JIS 10K

Body: ductile iron or cast iron, full EPDM lining

Disc: EPDM-coated ductile iron or fully lined EPDM disc

Stem: stainless steel 416/304, EPDM-backed, blowout-proof

Operation: handle lever / worm gear / pneumatic / electric

Design standard: EN 593, API 609 Category A, MSS SP-67

Test standard: API 598, EN 12266-1, ISO 5208

Leakage class: bubble-tight shut-off on water at rated pressure (resilient seat)

Selection and installation notes

Confirm the pipeline flange standard, bolt circle and gasket type before ordering to ensure correct lug drilling and compatible face-to-face length. For sewage service with abrasive grit content, specify hardened stem bearings and scraper rings to protect the EPDM stem seal from particulate damage. Install the valve with the disc shaft horizontal or vertical per manufacturer guidance; avoid mounting with the stem directly upward on slurry lines where sediment may accumulate in the stem gland. Allow sufficient clearance above the valve for handle rotation or actuator removal during maintenance. Trekre Valve engineers can review your medium analysis, temperature profile and cycle frequency to confirm EPDM lining suitability or recommend an alternative elastomer or fluoropolymer lining where chemical exposure exceeds EPDM limits.

Quality assurance and delivery

Each fully lined EPDM lug butterfly valve undergoes shell hydrostatic test, seat closure test and torque verification before shipment from our Wuxi factory. Material certificates for body castings, lining compound batch records and pressure test reports are available for project documentation packages. Surface protection includes internal desiccant packing and external primer or epoxy coating for storage and transit. Contact Trekre Valve for dimensional drawings, actuator sizing data and competitive quotations on handle-operated or gear-operated EPDM fully lined lug butterfly valves for your water, sewage or HVAC project.