Introduction
Figure-8 blanks (also known as spectacle blinds or 8-blanks) and pipe bends are essential components in industrial piping systems. Figure-8 blanks provide positive isolation for maintenance or flow control, while pipe bends allow directional changes without the pressure drop of a welded elbow. For EPC procurement engineers and industrial buyers, selecting the right design, material, and manufacturing standard is critical to system safety and longevity. This guide outlines key considerations for sourcing these components from global suppliers like Hebei Haihao Group.
Design and Function
A figure-8 blank consists of two discs connected by a handle: one solid (blind) and one open (spacer). When the solid disc is positioned in the flange gap, the line is positively isolated. Reversing the assembly aligns the spacer, allowing flow. This design eliminates the need for multiple gasket changes and provides rapid isolation. Pipe bends, on the other hand, are formed by bending a straight pipe to a specified radius—commonly 90° or 45°—offering a smooth flow path with minimal turbulence compared to multiple butt-weld elbows.
Applicable Standards
Procurement specifications should reference recognized international standards:
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