The API 609 Dual Plate Wafer Check Valve is a robust, space-saving solution for preventing backflow in high-performance piping systems, particularly where compliance with stringent industry standards is required. Proper selection based on fluid, pressure, and temperature ensures optimal performance.
The API 609 Dual Plate Wafer Check Valve is a critical component in piping systems, designed to prevent backflow and ensure unidirectional flow. Here are the key points about this valve:
Design & Construction
Dual Plate (Butterfly) Design: Features two spring-loaded hinged discs that open with forward flow and close with reverse flow.
Wafer Type: Lightweight, sandwiched between flanges, saving space and weight compared to lug or flanged types.
Compact & Lightweight: Ideal for tight spaces due to minimal face-to-face dimensions.
API 609 Compliance
Meets API 609 standards for butterfly valves, ensuring reliability in oil, gas, and petrochemical applications.
Covers design, materials, pressure-temperature ratings, and testing requirements.
Material Options
Body Materials: Carbon steel, stainless steel (SS316, SS304), alloy steel, duplex steel.
Seat & Disc Materials: PTFE, rubber, metal-to-metal for high-pressure/temperature.
Springs: Stainless steel for corrosion resistance.
Pressure & Temperature Ratings
Pressure Class: Typically 150# to 600# (ASME B16.34).
Temperature Range: -20°F to 1000°F (-29°C to 538°C), depending on materials.
Applications
Industries: Oil & gas, petrochemical, water treatment, power plants, HVAC.
Fluids: Water, steam, oil, gas, corrosive/abrasive media (material-dependent).
Installation & Maintenance
Flange Compatibility: Fits between ANSI/ASME, DIN, or EN standard flanges.
No External Actuation: Relies on flow pressure; no manual/automated control needed.
Easy Maintenance: Few moving parts; inspect discs, springs, and seats periodically.
Testing & Certifications
Hydrostatic Test: Per API 598 (shell & seat leakage tests).
Fire Testing: API 607/6FA for fire-safe versions.
NACE MR0175: For sour service (H₂S environments).
Advantages Over Other Check Valves
Lighter & Smaller than swing or lift check valves.
Faster Response Time than swing checks.
Cost-Effective for large diameters.
Materials of Main Parts
| Main Part |
Standard Material (ASTM) |
Alternative Materials (Optional) |
| Body |
A216 WCB (Carbon Steel) |
A351 CF8 (SS304), CF8M (SS316), CF3 (SS304L), CF3M (SS316L), A352 LCB/LCC (Low Temp), A995 CD3MN/4A (Duplex) |
| Dual Plates (Discs) |
A216 WCB / A351 CF8/CF8M |
SS316, SS316L, Duplex (2205), Super Duplex (2507), Alloy 20 |
| Hinge Pins |
A182 F6a (13Cr) / SS410 |
A182 F304/F316 (SS304/SS316), 17-4PH |
| Spring (if applicable) |
A313 (SS304/SS316) |
Inconel 718, Hastelloy C276 |
| Seat Ring |
A105 + Stellite / SS304/SS316 |
A182 F304/F316, Hard-faced (Stellite 6), PTFE Coated |
| Gasket |
Graphite + SS304/SS316 Spiral Wound |
PTFE, Flexible Graphite, Metal Jacketed |
| Bolts & Nuts |
A193 B7 (Alloy Steel) + A194 2H |
A320 L7 (Low Temp), A193 B8 (SS304), B8M (SS316) |
Main Material of API Valve
What is the difference between a rising stem gate valve and a non rising stem gate valve?
API Valve Fire Test
What is the difference between PTFE and RPTFE?