Inspection of Glass-Lined Equipment - A Refresher

If it's glass-lined, chances are the environment is very corrosive to most metallics. In general, once the glass lining is breached, through-wall corrosion doesn't take very long. An effective maintenance, operation and inspection program will go a long way in minimizing this possibility.

There are different types of glass, varying in their corrosion and mechanical wear and impact resistance. Here are a few things to think about before, during and after inspection.

Tank Preparation

Follow your company tank entry procedure and lockout procedures, as applicable. Your company's PSM program should address this.

Assure yourself the tank is clean enough for entry. Remember, materials aggressive enough to warrant glass can be very unpleasant, toxic, acidic, oxidizers and/or dangerous.

Make sure material is not trapped in the nozzles prior to inspection. Effective breathing, face, body and eye protection are recommended. Remember, you'll likely be inserting inspection tools into the nozzles, which could dislodge trapped product and fall onto you.

One advantage to disconnecting pipe work from the tank nozzles is access to gasket areas for visual inspection and spark testing. Make sure those removing the pipe work cover the unprotected gasket faces and nozzles to eliminate potential for gasket face damage and droppage into the tank, this includes the manways. Rubber-type covers are commercially available. At a minimum tape cardboard cutouts over the surface. Replace the protective device after inspection.

A potential disadvantage to removing the piping at the nozzle is spalling or cracking damaging the gasket surface area during re-attachment of pipe work. Make sure the manufacturer's recommended torquing procedures are used by the mechanics during this process.

If others, e.g. mechanics, etc. are to enter the tank for modifications, internal replacements, etc. make sure the inspection is performed after and that the inspector is the last person in the tank. This should catch any damage that may occur during the work.

Rope, wood or fiberglass ladders work well and minimize mechanical damage potential. A rubber mat on the floor is a good safeguard, too.