Butterfly Valve

Core Design Specifications
Body Type: Common configurations include Wafer (sandwiched between flanges), Lug (threaded inserts for end-of-line service), and Double-Flanged (integral flanges for heavy-duty use).

Disc Design:
Concentric (Zero Offset): The stem passes through the centre of the disc and seat; ideal for low-pressure, non-critical applications.

Double Offset (High Performance): Stem is offset from the seat and body centreline to reduce friction and wear.

Triple Offset: Incorporates a third angular offset for bubble-tight sealing in high-pressure/temperature steam or chemical services.

Size Range: Typically available from DN40 (1.5″) to DN3800 (120″) or larger.

Pressure Ratings: Standard ratings include PN6, PN10, PN16, PN20, and ASME Classes 150, 300, and 600.

Material Specifications (MOC)
Materials are selected based on the medium (liquid, gas, or slurry) and temperature:

Body: Cast Iron (IS 210 FG 200), Ductile Iron, Cast Carbon Steel (ASTM A216 WCB), or Stainless Steel (CF8M).
Disc: CF8 (SS304), CF8M (SS316), Aluminum Bronze, or Nylon-coated Ductile Iron.
Seat: Resilient materials like EPDM (standard water), Nitrile (oil/gas), PTFE/Viton (chemicals), or Metal-to-Metal for high-temperature service.
Stem: Often AISI 410, 304, or 316 stainless steel.
Operation and Testing
Actuation: Hand lever (up to 150/200mm), Worm gear (200mm and above), or Pneumatic/Electric actuators.
Leakage Class: Generally compliant with EN 12266-1 Rate A (zero leakage) or ANSI/FCI 70-2 Class VI.
Standard Tests: Hydrostatic Body Test (typically 1.5x working pressure) and Seat Leakage Test (1.1x working pressure).
For detailed dimensional data based on specific flange standards (ANSI B16.5 vs DIN PN16),