Manual Wafer Butterfly Valve D71X

Manual Wafer Butterfly Valve D71X Purpose

This Wafer Butterfly Valves is used as a cutoff and adjusting equipment for the various water supply and drainage pipelines in building chemical, medicine, textile, ship and other industries.

Manual Wafer Butterfly Valve D71X Main part materials

Disc for DN50~DN300 could use Ductile lron with Epoxy

Manual Wafer Butterfly Valve D71X Main dimensions(mm)

Manual Wafer Butterfly Valve D71X Definition and Components

A Manual Wafer Butterfly Valve Model D71X is a quarter-turn, lightweight isolation valve designed to be clamped between two pipeline flanges without needing through-bolts. The "D71X" designation typically indicates a specific model series, where "D" often stands for butterfly valve, "71" may refer to a lever-operated, lug-less wafer design, and "X" commonly signifies an EPDM (Ethylene Propylene Diene Monomer) rubber seat—a standard for cold water services. It provides reliable on/off control in a compact form factor.

Butterfly Valve for Water Main Parts:

• Wafer Body: The central, disc-shaped housing (typically ductile iron) that fits between flanges. It has through-holes for the pipeline's flange bolts.
• Disc (Butterfly): The circular plate (typically ductile iron or stainless steel) that rotates 90° to allow or block flow.
• Stem (Shaft): A one-piece or two-piece shaft (typically stainless steel) that connects the disc to the actuator and transmits the turning force.
• Resilient Seat (EPDM): A ring of elastomer (EPDM rubber) bonded or fitted into the body against which the disc seals to provide a bubble-tight shut-off.
• Stem Seals (O-rings/Gaskets): Prevent medium leakage along the stem.
• Manual Actuator (Lever Handle): A simple handle for 90° manual operation, often with a locking plate to secure the valve in the open or closed position.
• Bushings/Bearings: Support the stem within the body for smooth rotation.

Role, Characteristics, and Application Scenarios of Manual Wafer Butterfly Valve D71X in Pipelines

Water Valves Functions in Pipelines:

• Isolation/On-Off Service: Primary function is to start or stop fluid flow in a pipeline.
• Basic Flow Regulation: Can be used for moderate throttling, though not as precise as a globe valve.

Operational Features:

• Compact & Lightweight: The wafer design offers significant space and weight savings compared to gate valves.
• Quick Quarter-Turn Operation: 90° rotation from fully open to fully closed.
• Bidirectional Sealing: Typically provides effective sealing against flow from either direction.
• Lug-less Design: Relies on the pipeline flange bolts for structural integrity and sealing compression.
• Low Pressure Drop: When fully open, the disc presents minimal obstruction to flow.

Common Scenarios:

• HVAC Systems: Chilled and cooling water lines.
• Water & Wastewater Treatment: Pump discharge/suction, distribution lines.
• General Industrial Service: Low-pressure process water, air, and other non-aggressive media lines.

Irrigation Systems.

Manual Wafer Butterfly Valve D71X Standards: Materials, Design, and Connections

Material Standards:

• Body: Ductile Iron (ASTM A536) with epoxy coating (e.g., powder coat).
• Disc: Ductile Iron (ASTM A536) or Stainless Steel (ASTM A351 CF8/CF8M).
• Stem: Stainless Steel (AISI 416/304/316).
• Seat: EPDM (for water up to ~85°C/185°F), NBR, or Viton for other media.
• Seals: NBR or EPDM O-rings/gaskets.

Design & Performance Standards:

• API 609: The key standard for "Butterfly Valves: Double Flanged, Lug- and Wafer-Type."
• ISO 5752: Standard for "Face-to-face dimensions of metal butterfly valves."
• Pressure Rating: Common: PN10/PN16 (Class 150) for standard service.
• Leakage: Seat leakage rates often conform to ISO 5208 Rate A (zero leakage) or Rate B.

Connection Standards:

• Wafer Design: Conforms to ANSI/ASME B16.10 face-to-face dimensions and fits between ANSI/ASME B16.1 (Cast Iron) or B16.5 (Steel) flanges.
• Flange Compatibility: Designed for standard raised face (RF) or flat face (FF) flanges. The valve thickness matches the "face-to-face" dimension for the corresponding pipe size and pressure class.

How to Select Manual Wafer Butterfly Valve D71X

Purchasing Guide:Define Critical Application Parameters:

• Fluid Media & Temperature: Confirm EPDM seat compatibility (e.g., water, mild chemicals, <85°C).
• Pressure Rating: Required PN (Pressure Nominal) or Class (e.g., PN16/Class 150).
• Pipe Size & Flange Standard: Exact nominal diameter (e.g., DN150 / 6") and flange standard (e.g., ANSI B16.5 Class 150 RF).
• Material Preference: Standard is epoxy-coated ductile iron body with SS disc/stem. Upgrade if needed (e.g., full SS for corrosive environments).

Specify Technical & Quality Requirements:

• Operational Torque: For larger sizes (>8"), consider a gear operator instead of a lever.
• Standards Compliance: Specify conformance to API 609 or equivalent.
• Testing & Certification: Require a factory test certificate (shell & seat test per API 598). Request material certificates for critical parts.

Supplier Evaluation & Logistics:

Source from established valve manufacturers or specialized industrial suppliers.

Compare prices, but prioritize suppliers providing full technical data and certifications.

For large orders, request a product sample for dimensional and functional verification before full production.

Pre-Shipment Inspection for Export Manual Wafer Butterfly Valve D71X and Key Considerations

Inspection Checklist: