Spectacle blind, open (spacer in line)
ISO 10628-2 (groups 24-25, fittings and piping) / PIP PIC001 / ASME B16.48
Drawn as
A figure-8 between two flange bars: the open ring sits on the pipe, and the solid (filled) blank sits off the line.
Meaning
Spectacle blind in the open position: flow passes through the ring. It is turned to the closed position for positive isolation during maintenance. Becomes spectacle-blind.
Variants
- Some legends write "NO" (normally open) beside it
- Spectacle blinds in plant isolations are often marked NO / NC
- The offset form (figure-8 beside the flange pair on a short stem) means the same thing: see spectacle-blind-offset
Tags
SB