Line Blinds

HIS Line Blinds are manufactured to exacting specifications and represent a cost-effective, potential solution to what would normally be substantially more expensive block & bleed style valves or to a more efficient and convenient alternative to “blanking plates” which have substantial labor costs associated with their insertion and removal. The outstanding inherent design feature of the HIS Line Blind that should be recognized is the fact that there can be NO leakage downstream of the Line Blind – it is not physically possible! The only possible leak path of the Line Blind is to atmosphere and this can only happen in the HIS design when the o-ring seal has not been properly maintained or is damaged. The alternative is insertion of a blind flange between a pair of mating flanges and to compare the two alternatives:

Flanged End

Welded End

Flanged by Welded End

Click on any photo to enlarge

Line Blind Spectacle Plate on Lathe

Machined Body Flange

Sandblasting

Line Blind Assembly

Pivot Jack Bolt (cut away)

Swing Bolt (cut away)

There are important distinctions when it comes to maintenance as well. First, where a pipe is being blinded for personnel protection or product contamination reasons during a maintenance cycle the HIS Line Blind provides a positive indication of its open or closed position and a positive seal to the downstream piping. The HIS Line Blind can never fail to close or leak downstream due to wear, erosion, corrosion or other factors Further, in advance of shutdown, the seals can be visually inspected and replaced while the system is still in operation.

Jack Bolt

Swing Bolt

Double Flanged

Ready to Ship

In Service