We've seen many times that an existing pipeline experiences wall thickness loss due to some corrosion or damage to the factory applied coatings. In cases like that, a pig generally discovers this wall loss and a repair of some kind must be made. Assuming that some wall thickness still exists; the pipe is excavated and often times a steel repair sleeve is welded onto the damaged area in order to 'rebuild' the wall thickness there (it is my understanding that a Clockspring is sometimes used as well).
In many of those cases, the steel repair sleeve is uncoated. In addition, since the steel repair sleeve is welded in; the process damages the adjacent factory applied coatings. The result is that a pipeline coating is needed there. There are a couple of potential issues; as the line is often an active line (or at least a full line) which tends to prevent preheating (a necessary step of just about any worthwhile coating).
When I'm approached with this type of a problem; I know that our heat shrink sleeves are definitely a great solution. We utilize our S1301M liquid epoxy to act as the bonding agent; we include mastic logs to pack at the step down area to fill any potential cavity there at the step down (since the step down is typically pretty significant at 1/2" or more) and we supply a shrink sleeve that will protect that steel repair sleeve for the life of the line. Simple installation, no special training required; proven methods. Everybody wins.
In many of those cases, the steel repair sleeve is uncoated. In addition, since the steel repair sleeve is welded in; the process damages the adjacent factory applied coatings. The result is that a pipeline coating is needed there. There are a couple of potential issues; as the line is often an active line (or at least a full line) which tends to prevent preheating (a necessary step of just about any worthwhile coating).
When I'm approached with this type of a problem; I know that our heat shrink sleeves are definitely a great solution. We utilize our S1301M liquid epoxy to act as the bonding agent; we include mastic logs to pack at the step down area to fill any potential cavity there at the step down (since the step down is typically pretty significant at 1/2" or more) and we supply a shrink sleeve that will protect that steel repair sleeve for the life of the line. Simple installation, no special training required; proven methods. Everybody wins.
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