Terminal Rack - Delaware, USA
On a terminal rack in Delaware - USA, a total of 8 pipes across 71 supporting I-beams had to be lifted to install new wear pads at the pipe touchpoints. The pipes ranged in size from 2” to 20” and in total the rack has 568 touchpoints, all of which required wear-pad installation.
Some of the touchpoints had severe anti-corrosion wear-pad failures which enabled water entrapment and accelerated the development of corrosion. Attending to this problem early on was essential to ensuring the longevity of these assets.
The operational challenge was to safely lift the pipes and gain access to the touchpoints to perform the required remedial work in a timely manner. Because the facility is elevated over water crews did not have access beneath the pipe rack, so all work had to be performed from above. But without supporting structures to lift from above and no access for a crane of any size, lifting options were severely limited.
Conventional lifting methods are also limited to lifting one line at a time. Complicating the operation further is that the terminal is active and the operating conditions of some pipes can change from live to inactive but full, and at other times empty.
The contracting crew consisted of 5 painters who were trained to handle and operate the jacks during the first 2 days of the project. The lift was engineered to accommodate all combinations of pipe operating conditions allowed crews to continue work irrespective of their current state, and procedures safely mitigated the risks of lifting under live conditions. Using a total of 12 jacks (4 jacks per supporting I-beam) and lifting from every second support, simultaneous access was provided to a total of 40 touchpoints across 5 pipe supports.
Life lines were erected across each support with modular walkways installed on either side of each support. The jacks were mechanically locked out before crews were allowed to work on the touchpoints beneath the pipes.
Touchpoints in the middle of the production cycle were tended to. This includes a full inspection and cleaning before a new coat of paint was applied to both the pipe and supporting I-beam. This was then allowed to cure overnight. Wear pads were glued on the second day, the edges were sealed to prevent water entrapment and the surfaces of the ware-pads were also painted.
A leap frogging technique was used whereby jacks on the trailing end of the production area are moved to the leading end to create new access. In the first 3 weeks of production 209 touchpoints were accessed and repaired, and in week 5 a total of 440 touchpoints were accessed and repaired. All 568 touch points were repaired within 7 weeks.