Guide to Selecting the Right Butterfly Valve
Selecting the correct butterfly valve requires understanding your application’s pressure, temperature, flow control needs, and fluid type. Below is a step-by-step guide to ensure optimal performance and longevity.
2 inch butterfly valve, 3 inch butterfly valve, 4 inch butterfly valve, 6 inch butterfly valve, 8 inch butterfly valve, double eccentric butterfly valve，flanged butterfly valve, lug butterfly valve, pneumatic butterfly valve, stainless steel butterfly valve, triple offset butterfly valve, Wafer Butterfly Valve
1. Determine Valve Type Based on Design
| Type | Best For | Pressure Range | Seal Type |
|---|---|---|---|
| Wafer | Low-pressure water/air | ≤ 150 PSI | Rubber/PTFE |
| Lug | Dead-end service, easy removal | ≤ 150 PSI | Rubber/PTFE |
| Flanged | High-pressure systems | Up to 1,450 PSI | Rubber/PTFE/Metal |
| Double Offset | HVAC, moderate throttling | Up to 250 PSI | PTFE/Metal |
| Triple Offset | Zero leakage, high-P/temp | Up to 1,450 PSI | Metal |
Recommendation:
-
Water treatment? → Wafer or Lug (EPDM seat).
-
Oil & gas? → Triple-offset (metal seat, fire-safe).
2. Material Selection (Body & Disc)
| Material | Fluid Compatibility | Max Temp | Applications |
|---|---|---|---|
| Cast Iron | Water, air | 250°C | HVAC, general purpose |
| Ductile Iron | Water, mild chemicals | 350°C | Water distribution |
| Stainless Steel (CF8M/316SS) | Corrosive fluids | 600°C | Chemical, marine |
| Duplex Stainless | Seawater, chlorides | 300°C | Offshore, desalination |
| Nickel-Aluminum Bronze | Seawater, steam | 400°C | Marine, shipbuilding |
Key Tip:
-
For corrosive fluids (acids, chlorine), use PTFE-lined SS valves.
3. Seat Material (Sealing Performance)
| Seat Type | Leakage Class | Max Temp | Best For |
|---|---|---|---|
| EPDM Rubber | Class VI (bubble-tight) | 120°C | Water, air |
| Nitrile (NBR) | Class VI | 80°C | Oils, fuels |
| PTFE | Class VI | 200°C | Chemicals, steam |
| Metal (Stellite/316SS) | Class IV (low leakage) | 600°C | High-P/temp |
Critical Choice:
-
Zero leakage? → PTFE or EPDM.
-
Fire-safe? → Metal seat (API 607 certified).
4. Actuation Method
| Actuator Type | Operation | Best For |
|---|---|---|
| Lever/HANDWHEEL | Manual, quarter-turn | Small valves, low torque |
| Gear Operator | Manual, high torque | Large valves (≥12″) |
| Pneumatic | Automated, fast response | Frequent cycling |
| Electric | Precise control | Remote operation |
| Hydraulic | High-force applications | Offshore, heavy industry |
Rule of Thumb:
-
Valves > 12″ usually need gear or actuators.
5. Pressure & Temperature Limits
-
Check ASME B16.34 ratings for your valve’s pressure class (e.g., 150, 300, 600 PSI).
-
Example:
-
EPDM seat → Max 150 PSI @ 120°C.
-
Metal seat → Up to 1,450 PSI @ 600°C.
-
Always derate for high temperatures!
6. Certifications & Standards
| Standard | Purpose |
|---|---|
| API 609 | Design/testing for triple-offset valves |
| ISO 5752 | Face-to-face dimensions |
| API 607 | Fire-safe testing |
| AWWA C504 | Waterworks applications |
Critical for:
-
Oil & gas → API 609, NACE MR0175 (sour service).
-
Potable water → NSF/ANSI 61 certified.
7. Top Butterfly Valve Manufacturers
| Brand | Specialization |
|---|---|
| Emerson (Keystone) | General-purpose, HVAC |
| Flowserve (Argus) | Triple-offset, high-P |
| Crane (Xomox) | Chemical, lined valves |
| DeZURIK | Water/wastewater |
| Bray | Fire-safe, oil & gas |
8. Selection Checklist
✅ Valve type (wafer, lug, triple-offset)
✅ Body/disc material (cast iron, SS, duplex)
✅ Seat material (EPDM, PTFE, metal)
✅ Actuation (manual, pneumatic, electric)
✅ Pressure/temperature rating (ASME B16.34)
✅ Certifications (API 609, NSF, NACE)
Final Recommendation
-
Water treatment? → Wafer-style, EPDM seat, ductile iron body.
-
Oil & gas? → Triple-offset, metal seat, API 609 compliant.
-
Chemical processing? → PTFE-lined SS, pneumatic actuation.