With an overall goal of “maximizing company investment while protecting the environment and worker safety”; this paper takes a new look at taking care of critical FRP equipment.

There are two separate strategies for the maintenance of FRP: Some equipment can be run-out and replaced and others must be perpetually repaired with no option to replace it. These take two very different approaches.

Acting on these strategies requires being able determine both the Tactile and Technical condition of fiberglass. Tactile are changes that you can detect with the senses, with or without equipment: Surface damage, thickness and changes in the appearance that predict failure. Technical changes are things that known to occur within a laminate in industrial service that are not visible to the eye of an experienced observer. These changes weaken the laminate in tensile and flexural, and are often the underlying cause of the Tactile damage you see.

It is important to know the Tactile condition of equipment of course and effective the best current ways to do that are discussed. But understanding the Technical condition determines if a particular system should be continuously patched-up or removed and replaced. This paper looks at the tasks and the tools available to do this with an emphasis of doing it in-situ or while the equipment is running which is the most practical and we believe, the most effective way to do it.


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[EXCERPT] : Two Strategies and Four Tasks with One Goal; Reliable Fiberglass (FRP) Equipment

Todd Bishop, Owner
BRER Technical, Inc.
Bellingham, WA
Email
TAPPI PEERS Conference
Jacksonville, FL September 2016

This paper will discuss the one goal of fiberglass reliability, two over-arching strategies and four distinct tasks required to achieve that goal. We will then discuss the tools available to complete the tasks and realize the goal.

Others are more qualified to talk about the reasons for conditions in the pulp market today including reduced use of paper, foreign competition, globalization of markets and increasing regulatory focus on environment and safety. The effect on those working in the day-to-day operation of a pulp plant is always doing more with less money and time and above all else, avoiding an in-service failure.

One Goal:

The goal with respect to FRP maintenance then, is to maximize company investment while simultaneously maximizing worker safety, productivity and environmental responsibility. This must be accomplished in light of ever shortened outage opportunities. “On-line” inspection with specialized testing techniques is a viable option.

Two Strategies:

Piping is replaceable while most tankage is not practically replaceable. This results in two different strategies. Businesses cannot afford too much repair at once, so both strategies must be managed and practical.

Strategy 1: Long-term preservation: Repair-in-place tankage must be managed to protect the long term viability of the tank shell. This strategy is preemptive but must not be overly so. In this strategy, a tank will be repaired well before it is in any danger of structural failure to preserve the asset. In fact, it is best to allow about 0.05” of relatively undamaged corrosion barrier remaining to allow room for demolition so that some corrosion barrier is in place for bonding.

Strategy 2: Replacement: Piping and replaceable tankage needs to be used until it is no longer consistent with the goal. Replacement is preemptive only with respect to business realities. This strategy requires that replacement be timed as close as reasonable to the point where the equipment can no longer be reliably used. This may or may-not be defined by simple, well-established and known limits like the condition of the veil or the mat layers of the corrosion barrier.

Why is it important to discuss the differences between these two strategies? Because it effects the type of testing and inspection that is appropriate in any circumstance. For instance, equipment that is governed by replacement maintenance strategy may be limited only by its remaining tensile or flexural strength but a vessel that is to be relined and maintained for the long-term needs to be repaired long before that point.

What is failure anyway? In reality, there is no easy point of “failure”. The question is, will the equipment last for a few more years. Many of us were taught that FRP had “failed” when the veil was gone, or more properly, when there is no corrosion barrier left. This is a convenient benchmark that has served well, but in today’s market, owners just want to know how much longer it will keep working and how to avoid getting trapped into excessive plant-wide repairs and-or wholesale replacement of equipment that should have been repaired in place. In short, it is a complex problem.