Internal Wet Layup Case Study

Strengthening of Pipes with Internal Wet Layup

Corrosion of steel reinforcement is a major cause of failure and potential collapse of these pipes. Numerous such collapses have been reported in the U.S. in recent years, resulting in significant loss of property.

A number of solutions and lining systems have been offered in recent years. However, these techniques add little (if any) additional strength to the pipe.

What sets the QuakeWrap system apart from other liners is the tremendous strength that carbon fiber reinforced polymer (CFRP) adds to the pipe. In many cases, the strength of the pipe can be increased significantly beyond the original!

Among the clients of QuakeWrap are a number of major utilities, including the largest nuclear generating station, in the U.S. In a number of PCCP pipes in this facility, corrosion of the steel wires had resulted in cracking of the concrete and weakening of the pipes. During an on-site demonstration, the steel strands in a new pipe were intentionally cut to model a pipe in which the strands have been lost due to corrosion. The weakened pipe was wrapped with QuakeWrap® carbon fiber reinforced polymer (CFRP), its ends were capped with steel plates and the pipe was pressurized. Testing was stopped when the pipe pressure exceeded the original design strength of the pipe. This clearly demonstrated the feasibility of this technique.

A major concern for most pipe repair projects is the time required to complete the repair. Our tack coat is a high viscosity thixothropic epoxy. As part of the approval process, it was demonstrated that a single coat of tack coat applied to the surface of the pipe is strong enough to support the weight of three layers of a very heavy carbon fabric; this leads to faster construction time and significantly reduces downtime of the system.

QuakeWrap system can be custom-designed to meet the needs of the clients. For example, in the case of the nuclear power plant, QuakeWrap was the only vendor that could design and construct a special fabric with sufficient strength in the longitudinal and hoop directions. This resulted in lowering the number of wraps in the pipe from 5 layers to 3 layers, leading to the significant shorter construction time. In another application for Power Service of New Mexico, we designed and constructed yet another special carbon fabric that could strengthen the pipe with application of a single layer of carbon fabric.

Among other notable pipeline rehabilitation projects of QuakeWrap by the wet layup method are ​

  • 54″ PCCP & 45″ Steel Pipe 
  • 120″ Steel Pipe 
  • 90″ CCGFRP Pipe Repair
  • 84″ RCP Lining
  • 120″ PCCP Lining

For detailed descriptions of select QuakeWrap pipe lining projects with the wet layup method, please click the links below.