Manual Wafer Butterfly Valve D371X

Manual Wafer Butterfly Valve D371X Purpose

This Wafer Style Butterfly Valve 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 D371X Definition and Components

A Manual Wafer Butterfly Valve Model D371X is a quarter-turn, lug-less wafer-style isolation valve designed for installation between two pipeline flanges. The "D371X" model code is significant: "D" typically denotes a butterfly valve, "3" signifies a gear-operated manual actuator, "71" indicates a wafer body design, and "X" represents a resilient EPDM seat. This fire protection valves is engineered for applications requiring higher operating torque than a simple lever handle can provide, offering better mechanical advantage and control.

Water Supply Valves Main Parts:

• Wafer Body: The central, disc-shaped housing (typically ductile iron) that fits between pipeline flanges. It has bolt holes for the flange studs to pass through.
• Disc (Butterfly): The circular plate (often stainless steel or ductile iron coated) that rotates to control flow.
• Stem (Shaft): A robust stainless steel shaft connecting the disc to the gearbox.
• Resilient Seat (EPDM): An elastomer ring (Ethylene Propylene Diene Monomer) that provides a tight seal against the disc.
• Manual Gear Operator (Worm Gear Actuator): The key feature. Consists of a handwheel that turns a worm gear, which rotates the valve stem. This provides high torque multiplication for easier operation of larger valves or valves under higher pressure.
• Position Indicator: Shows the degree of disc opening (e.g., 0°, 45°, 90°).
• Stem Seals & Bushings: Prevent leakage and support smooth rotation.

Role, Characteristics, and Application Scenarios of Manual Wafer Butterfly Valve D371X in Pipelines

Functions in Pipelines:

• Isolation/Shut-off: Primary function for stopping flow in a pipeline.
• Throttling/Regulation: The gear operator allows for precise intermediate positioning to regulate flow or pressure.
• Bidirectional Blocking: Effective sealing against pressure from either flow direction.
• Operational Features:
• High-Torque Operation: The gearbox reduces the effort required to operate the valve, making it suitable for larger sizes (typically DN150 / 6" and above) and higher differential pressures.
• Precise Flow Control: The multi-turn handwheel allows fine adjustment of the disc position.
• Compact Wafer Design: Saves space and weight compared to gate valves; does not require its own flange bolts.
• Durable for Frequent Operation: Gear mechanism is more robust for regular use than a simple lever.
• Locking Capability: Most gear operators have a provision for padlocking the valve in a desired position.

Common Usage Scenarios:

• Water Supply & Distribution Mains: For isolating sections of the network.
• Wastewater Treatment Plants: On pump discharge, aeration lines, and sludge lines.
• HVAC Systems: In large chilled water or heating water circuits.
• Industrial Process Lines: For water, compressed air, and other non-aggressive media.
• Power Plant Cooling Water Systems.
• Irrigation Canals and Pump Stations.

Manual Wafer Butterfly Valve D371X Standards: Materials, Design, and Connections

Material Standards:

• Body: Ductile Iron (ASTM A536) with epoxy powder coating (standard). Alternative: Carbon Steel (ASTM A216 WCB) or Stainless Steel (ASTM A351 CF8/CF8M).
• Disc: Ductile Iron with Ni-plating or Stainless Steel (ASTM A351 CF8/CF8M).
• Stem: Stainless Steel (AISI 431, 304, or 316).
• Seat: EPDM (for water, -20°C to 120°C), NBR, or Viton for chemical service.
• Gearbox Housing: Cast Iron or Aluminum Alloy.

Design & Performance Standards:

• API 609: The primary standard for "Butterfly Valves: Double Flanged, Lug- and Wafer-Type."
• ISO 5752: Standard for face-to-face dimensions.
• ISO 5211: Standard for mounting dimensions of gear operators (ensuring actuator interchangeability).
• Pressure Rating: Commonly PN10/PN16 (Class 150). Available up to PN25 (Class 150 for certain sizes).
• Leakage: Seat leakage typically meets ISO 5208 Rate A (bubble-tight) or Rate B.

Connection Standards:

• Wafer Design: Conforms to ANSI B16.10 face-to-face dimensions. Fits between standard ANSI B16.1 (Cast Iron) or B16.5 (Steel) flanges.
• Flange Compatibility: Designed for Raised Face (RF) or Flat Face (FF) flanges of the corresponding pressure class.

How to Select Such Manual Wafer Butterfly Valve D371X

Define Application Specifications:

• Fluid, Temperature, Pressure: Confirm media compatibility, max temperature (<120°C for EPDM), and required Pressure Nominal (PN) rating.
• Size: Exact nominal diameter (e.g., DN200 / 8").
• Material Specification: Standard is Epoxy-Coated Ductile Iron body, Stainless Steel disc/stem, EPDM seat. Request full material breakdown.
• Gearbox Specification: Required input torque (based on valve size/pressure), number of turns from open to closed, and handwheel type (e.g., with locking plate).

Specify Quality & Compliance Requirements:

• Standards: Explicitly state conformance to API 609.
• Testing & Documentation: Require a factory test certificate per API 598 (shell test & seat test). Request Material Test Reports (MTRs) for body, disc, and stem.
• Interchangeability: Ensure the gear operator complies with ISO 5211 mounting pad specifications.

Supplier Selection & Ordering:

• Source from reputable industrial valve manufacturers or authorized distributors.
• Provide a detailed inquiry data sheet. For bulk orders, request a production sample for pre-shipment approval.
• Compare Total Cost of Ownership, considering warranty, availability of spare parts (like seals, gear sets), and technical support.

Pre-Shipment Inspection for Export Manual Wafer Butterfly Valve D371X and Key Considerations

Visual & Dimensional Inspection:

• Check for damage to coating, gearbox, and handwheel.
• Verify nameplate data (Size, PN, Model, Materials) matches the purchase order.
• Measure face-to-face dimensions against ISO 5752.
• Ensure the disc rotates freely without binding by operating the handwheel through its full range. The position indicator should move correspondingly.

Review of Mandatory Documentation:

• Factory Test Certificate (API 598): This is non-negotiable. It must certify successful hydrostatic shell test (at 1.5x PN) and seat leakage test (at 1.1x PN).
• Material Certificates: Review MTRs for critical components.
• Packing List: Verify item count and description.

Butterfly Valve for Water Packaging Inspection:

• The valve must be dry and clean internally. The disc should be in a partially open position (approx. 5°) to relieve seat stress during transport.
• All machined faces and sealing surfaces must be protected by taped-on cardboard or plastic covers, not loose caps.
• The gear operator should be protected from impact. The handwheel must be secured to prevent rotation during transit.

Manual Wafer Butterfly Valve D371X Main Dimensions(mm)

Note:1. Other specifications and flange standards are available upon request.

2. Design and specifications are subject to change without prior notice.