1. PRODUCT OVERVIEW

The H76 Wafer Butterfly Check Valve is a dual-plate, spring-loaded non-return valve designed for automatic prevention of backflow in piping systems. The valve features a compact wafer body that is clamped between two pipeline flanges, resulting in a significantly shorter face-to-face dimension and lighter weight compared to conventional swing check valves. Its structural length is only 1/4 to 1/8 of a traditional flanged check valve, and its weight is only 1/4 to 1/20.

The H76 series is available in soft-seal (H76X) and hard-seal (H76H/H76Y/H76W/H76F) configurations to accommodate various media and temperature requirements. Common body materials include cast iron, ductile iron, carbon steel (WCB), and stainless steel.

2. WORKING PRINCIPLE

The H76 butterfly check valve consists of a body, two semi-circular discs, a central hinge pin, and torsion springs. The dual plates are suspended on a central vertical pin.

When forward flow begins, the fluid pressure pushes the discs open. The heel of each plate opens first, which prevents friction between the sealing surfaces during opening and eliminates wear on the sealing faces. When flow decreases or reverses, the torsion springs force the discs to close rapidly against the seat. The plate tip closes first, and the valve reaches bubble-tight shutoff.

Key operational features:

• Dual-plate design: Two spring-loaded semi-circular discs provide rapid, non-slam closure and low pressure drop.

• Wafer connection: The valve is clamped between two pipeline flanges using through-bolts, resulting in a compact and lightweight structure.

• Spring-assisted closure: The springs ensure quick disc closure and minimize water hammer.

• Horizontal or vertical installation: The valve can be installed in horizontal or vertical pipelines.

3. DESIGN & MANUFACTURING STANDARDS

Design Standard: API 594 / API 6D / JB/T 8937
Face-to-Face: API 594 / DIN 3202 / JB/T 8937 / GB/T 12221 / ISO 5752
Testing Standard: API 598 / JB/T 9092

4. MATERIALS OF CONSTRUCTION

5. PRESSURE & TEMPERATURE RATINGS

6. SIZE RANGE

7. DIMENSIONS

TABLE 1 – TYPICAL DIMENSIONS FOR H76X-10 / H76X-16 (PN10 / PN16) (Unit: mm)

Note: For H76X-16, dimensions may vary slightly. For detailed dimensional data per size and pressure class, please consult the manufacturer's certified drawing.

8. KEY FEATURES & BENEFITS

9. TYPICAL APPLICATIONS

• Marine & Shipbuilding – Seawater, fresh water, fuel oil, lubricating oil systems

• Water & Wastewater – Pump discharge, distribution networks, high-rise building water supply and drainage

• Petroleum & Chemical – Process piping, backflow prevention

• Power Generation – Cooling water, condensate, feedwater systems

• HVAC – Chilled water, heating systems

• Food & Pharmaceutical – Sanitary piping systems

10. ORDERING INFORMATION

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