Wafer-Type Butterfly Valve( ASTM A216 WCB body)
Description
TECHNICAL DATA SHEET
CENTRIC (MIDLINE) WAFER BUTTERFLY VALVE
Body: ASTM A216 WCB | Disc: ASTM A351 CF8 | Stem: ASTM A276 416 SS | Seat: EPDM
1. Valve Description
| Parameter | Specification |
|---|---|
| Type | Wafer Style, Centric (Midline) Design |
| Function | On/Off Service (Limited Throttling) |
| Operation | Manual Lever/Gear, Electric/Pneumatic Actuator (Optional) |
| Design Standard | API 609, ASME B16.34, MSS SP-67 |
| Face-to-Face | ASME B16.10 (Standard Wafer Pattern) |
| End Connection | Wafer (Clamped between ANSI/DIN/JIS Flanges) |
| Flow Direction | Bi-directional (Standard) / Uni-directional (Optional) |
2. Material Specifications
| Component | Material Standard | Material Grade | Details |
|---|---|---|---|
| Body | ASTM A216 | WCB | Carbon Steel |
| Disc | ASTM A351 | CF8 (≈304 SS) | Austenitic Stainless Steel |
| Stem | ASTM A276 | 416 SS | Martensitic Stainless Steel (Hardened) |
| Seat | – | EPDM | Ethylene Propylene Diene Monomer (Elastomer) |
| Stem Bushing | – | RPTFE/Bronze | Self-lubricating, Low Friction |
| Stem Seal | – | EPDM O-rings + Graphite Packing | API 598 Leakage Class ‘A’ |
| Fasteners | ASTM A193 | B7 (Carbon Steel) | Zinc Plated |
3. Pressure & Temperature Ratings
| Rating | Class 150 (PN16/20) |
|---|---|
| Max. Working Pressure | 150 PSI @ 150°F (10 bar @ 65°C) |
| Temperature Range | EPDM Seat Dependent: Min: -40°F (-40°C) Max: 250°F (121°C) |
| Test Pressure (Body) | 225 PSI (1.5x Class Rating) |
| Test Pressure (Seat) | 75 PSI (Air, Class VI Bubble-Tight) |
Note: Pressure rating decreases with temperature. EPDM degrades above 121°C – not suitable for steam >120°C.
4. Connection & Dimensions
| Parameter | Specification |
|---|---|
| Flange Standards | ANSI B16.5 Class 150, EN 1092-1 PN16, JIS B2220 10K |
| Face-to-Face | ASME B16.10 |
| Bore Type | Reduced Port (85% of nominal pipe size) |
| Available Sizes | DN40 ~ DN600 (NPS 1.5″ ~ 24″) |
5. Performance Data
| Characteristic | Specification |
|---|---|
| Leakage Class | ANSI/FCI 70-2 Class VI (Bubble-Tight, ≤ 0.1 bubbles/min) |
| Flow Characteristic | Quick Opening (Limited throttling capability) |
| Flow Coefficient (Cv) | Size-dependent (e.g., DN100: ~550) |
| Operating Torque | Low (Centric design advantage) – Charts available per size |
| Fire Safe | ❌ Not compliant with API 607/ISO 10497 (Requires metal seat) |
| Fugitive Emissions | ISO 15848-1 Class C (Standard) / Class B (Optional) |
6. Testing & Certification
| Test | Standard | Requirement |
|---|---|---|
| Hydrostatic Test | API 598 / ISO 5208 | Body: 1.5x Rating Seat: 1.1x Rating |
| Seat Leakage Test | API 598 | Air test for Class VI (6.9 bar air) |
| Material Certs | EN 10204 3.1 | Mill Test Reports (MTRs) |
| NDE | As per order | PT/MT on body (optional) |
7. Surface Treatment & Marking
| Area | Treatment |
|---|---|
| External Body | Shot blast (Sa 2.5) + Epoxy Paint (RAL 5015) |
| Internal Body | Bare WCB (shop primer optional) |
| Stem | Electroless Nickel Plating (ENP) or Passivation |
| Marking | Laser-etched per MSS SP-25: ● Size ● Class 150 ● WCB ● CF8 ● EPDM ● ↑↓ ● WAFER ● Manufacturer ID |
8. Applications
-
✅ Compatible Media: Water, Air, Weak Acids/Alkalis, Lubricants, Gases (≤10 bar), HVAC Systems.
-
⚠️ Limited Use: Low-pressure steam (<5 bar, <120°C), Light oils, Glycols.
-
❌ Not Suitable: Hydrocarbons (unless anti-static device fitted), Strong Oxidizers, Ozone, Ketones, Abrasive Slurries, High-Temperature Steam.
9. Key Limitations
-
Max Pressure: 150 PSI (10 bar)
-
Max Temperature: 121°C (EPDM)
-
No Fire Safe Certification
-
Avoid High ΔP Throttling
-
Not for Vacuum Service
10. Options & Accessories
-
Actuators (ISO 5211 Mounting Pad)
-
Position Indicators & Limit Switches
-
Locking Device (Lever Handle)
-
Anti-Static Device (for hydrocarbons)
-
Stem Extension (Insulated Systems)
-
Special Coatings (Internal Epoxy, Xylan)
