Company Name __________________________ Job Name __________________________ Date_________________
SIGHT GLASS SAFETY
Job Specific Topics:_____________________________________________________________________________________
The redline sight glass that we use on most of our atmospheric and LP Vessels it rated up to 390# at 150 deg. For an 8” S/G. That rating drops to 265# for a 24” S/G, 205# for a 36” S/G, 165# for a 48” S/G,, 125” for a 60” S/G and 90# for a 72” S/G. True, you may have a 275# WP vessel and an operating pressure of 60#, but the WP of the S/Gs on the vessel can lower the WP of the vessel and also possibly lower the PSH setting. So you have to keep this in mind with using this type of S/G on any pressurized vessel. Since most of the gauge cocks used for these kind of S/G’s do not have a big drain opening, you cant use a regular S/G brush to clean the glass. Instead, you have to remove the glass from the valves to clean it. When cleaning, be very careful not to bump or hit the glass, as this can maybe weaken the glass or maybe cause tiny cracks or scratches, which could reduce the WP of the glass itself. When placing the glass back into the valves, do not over tighten the packing nut, as this could cause the glass to crack or be under stress from the torque of the packing and nut turning around the glass. Make sure that the glasses have some kind of guard on them. Preferably one with a narrow front opening, and wide at the back so that, if the glass does breaks or burst, it will direct the glass back toward the vessel and not outward toward walkways or work areas. An expanded metal guard also works well in keeping the glass contained incase of breakage. Always wear PPE while working on the glass, especially eye protection when pressuring the glass back up. Another thing to check is the gauge cock itself, to ensure the check does work and stop fluid if the glass does break. This can be done by directing the flow in a bucket or into a drain with a piece of tubing and opening the bleed valve to see if the ball check will seat due to the increased flow.
Contribuited byWD 117-G Work Group(Charles Lasyone, James Herrington, Melvin Thew, David Bearden)