Economy Pattern Concentric Butterfly Valve
Description
Economy Pattern Concentric Butterfly Valve
Ductile Iron Body · CF8M Disc · EPDM Seat
1. PRODUCT DESCRIPTION
The Economy Pattern Concentric Butterfly Valve is a cost‑effective, resilient‑seated quarter‑turn valve designed for reliable on‑off and basic throttling service in general industrial and municipal applications. Featuring a concentric disc design with a ductile iron body, a stainless steel CF8M disc, and a moulded EPDM seat, this valve provides bubble‑tight shut‑off, low pressure drop, and long service life at an economical price point.
Its compact wafer‑type construction and lightweight design simplify installation between flanges, while the EPDM seat offers excellent resistance to water, wastewater, diluted acids, and mild chemicals. This valve is an ideal choice for HVAC, irrigation, water treatment, and process systems where cost efficiency is a priority without compromising fundamental performance.
2. DESIGN FEATURES
| Feature | Description |
|---|---|
| Valve Type | Concentric (centric) disc, resilient seated butterfly valve |
| Connection Type | Wafer‑type (flangeless) for mounting between standard flanges |
| Flow Direction | Bi‑directional |
| Disc Design | Concentric disc with central stem, reducing turbulence and pressure drop |
| Sealing | One‑piece moulded EPDM seat provides drop‑tight shut‑off (zero leakage) and compensates for minor disc misalignment |
| Stem Design | Anti‑blowout stem with square drive top; lower stem bearing reduces friction and wear |
| Actuator Mounting | ISO 5211 top flange for direct mounting of manual levers, gear operators, or actuators |
| Maintenance | Simple, low‑maintenance design with field‑replaceable seat |
3. TECHNICAL SPECIFICATIONS
3.1 General Parameters
| Parameter | Specification |
|---|---|
| Size Range | DN40 – DN600 (1½” – 24″) |
| Pressure Ratings | PN10 / PN16 / Class 150 |
| Design Standards | EN 593, ISO 5752, API 609, ASME B16.34 |
| Face‑to‑Face Dimensions | ISO 5752 Series 20 / EN 558 Series 20 / API 609 Table 1 |
| Flange Accommodation | DIN PN10/PN16, ASME Class 150, JIS 10K, BS 4504 PN10/PN16 |
| Top Flange | ISO 5211 (multiple sizes) |
3.2 Operating Conditions
| Parameter | Specification |
|---|---|
| Maximum Working Pressure | 1.6 MPa (16 bar) at ambient temperature |
| Maximum Pressure (Class 150) | 285 PSI @ 100°F (non‑shock) |
| Operating Temperature (Valve) | -10°C to +90°C (EPDM seat, continuous) |
| Peak Temperature (EPDM) | +120°C (intermittent) |
| Minimum Temperature | -10°C (EPDM) |
| Flow Velocity (Limit) | Up to 5 m/s (fully open, continuous service) |
4. MATERIAL SPECIFICATION
| Component | Material | Grade / Standard |
|---|---|---|
| Body | Ductile Iron (DI) | ASTM A536 Gr. 60‑40‑18 / EN‑GJS‑400‑15 |
| Disc | Stainless Steel CF8M | AISI 316 (ASTM A351 CF8M) |
| Stem / Shaft | Stainless Steel 416 / 420 | AISI 416 (hardened) |
| Seat (Liner) | EPDM (Ethylene Propylene Diene Monomer) | Moulded‑in type, vulcanised |
| O‑Ring | NBR (Buna‑N) or EPDM | — |
| Bearing | PTFE‑coated bronze / POM | — |
| Top Flange | Ductile Iron (integral with body) | — |
Optional seat materials: NBR (nitrile), Viton® (FKM), Silicone – available on request.
5. PERFORMANCE & TESTING
| Test | Requirement |
|---|---|
| Body Shell Test | 1.5 × rated pressure (hydraulic), no visible leakage |
| Seat Leak Test | 1.1 × rated pressure (pneumatic or hydraulic) |
| Allowable Seat Leakage | Rate A – zero leakage (bubble‑tight) per API 598 / JIS B 2003 |
| Bi‑directional Sealing | 100% tight shut‑off in both flow directions |
| Cycle Life | ≥ 50,000 cycles (under rated conditions) |
| Fire‑safe Design | Available as an option |
6. DIMENSIONS (Typical – Wafer Type)
All dimensions are for reference. Consult factory for certified drawings.
| DN | Face‑to‑Face (mm) | Approx. Weight (kg) |
|---|---|---|
| 40 | 33 | 1.2 |
| 50 | 43 | 1.8 |
| 65 | 46 | 2.5 |
| 80 | 46 | 3.5 |
| 100 | 52 | 4.8 |
| 125 | 56 | 6.5 |
| 150 | 56 | 8.5 |
| 200 | 60 | 13.0 |
| 250 | 68 | 20.0 |
| 300 | 78 | 30.0 |
| 350 | 78 | 42.0 |
| 400 | 102 | 58.0 |
| 450 | 114 | 75.0 |
| 500 | 127 | 95.0 |
| 600 | 154 | 135.0 |
Face‑to‑face per ISO 5752 Series 20 / EN 558‑1 Series 20.
7. APPLICATIONS
-
Potable and raw water distribution
-
Wastewater and sewage treatment
-
HVAC (heating, ventilation, air‑conditioning)
-
Irrigation and agricultural systems
-
Fire protection systems
-
Cooling water and industrial process lines
-
Food and beverage (with compatible seat material)
-
Pneumatic conveying and light slurry services
8. OPTIONS & CUSTOMIZATIONS
| Option | Details |
|---|---|
| Seat Materials | NBR, Viton® (FKM), PTFE, Silicone |
| Disc Materials | Ductile iron with nylon/epoxy coating, aluminum bronze |
| Stem Materials | Stainless Steel 304, 17‑4PH, Monel |
| End Connections | Wafer (standard), Lug‑type, Flanged |
| Operation | Manual lever, worm gear operator, electric actuator, pneumatic actuator, hydraulic actuator |
| Coating | Epoxy coating (minimum 250 µm) for corrosion protection |
| Insulation | Thermal insulation jacket for extreme temperatures |
9. APPLICABLE STANDARDS
| Standard | Description |
|---|---|
| EN 593 | Industrial valves – Butterfly valves |
| ISO 5752 | Face‑to‑face and centre‑to‑face dimensions |
| API 609 | Butterfly valves: wafer, lug, and double‑flanged |
| ASME B16.34 | Valves – Flanged, threaded, and welding end |
| ISO 5211 | Actuator mounting interfaces |
| API 598 | Valve inspection and testing |
| MSS SP‑67 | Butterfly valves |
| NSF/ANSI 61 & 372 | Potable water applications (with EPDM seat and appropriate coatings) |
This technical data sheet is provided for general reference only. Specifications are subject to change without notice. For specific project requirements, please consult the manufacturer or our technical support team.







