Page 369 - Trenchless Technology Piping Installation and Inspection

Inspection and QA/QC for Trenchless Installation and Replacement Methods 319

Again, all pipe sections that do not comply with the specifications
and/or show signs of defects or cracks must be immediately removed
from the jobsite.

Pipe Transportation and Storage
Jacking pipes must be properly transported and stored at the con-
struction site in such way that they are secured against rolling and
sliding. Excessive stacking heights must be avoided so that pipes in
the lower part of the stacks are not overloaded. Stacks of pipes should
not be placed close to open trenches or shafts. Pipes with protective
coatings must be stored on supports above ground to avoid damage
to coatings and joints. All pipe sections must be stored on supports in
very cold weather to avoid ground freezing. Elastomeric jointing
components must be kept clean and be protected from sunlight,
hydrocarbons, and extreme temperatures.
Careless handling can damage all pipe components. Any kind of
high impact or point loadings create a hazard for sensitive elements
of pipe joints, linings, or coating systems. Specific examples include
• Ends of concrete pipes are sensitive to impact damages due to
the large weight of each pipe section.
• Pipe coatings made of relatively soft materials can be dam-
aged during handling and backfilling. They may also become
brittle in cold weather and must be handled with extra care.
• Rubber gaskets are subject to damage from sunlight or
improper lubricants.
Pipes, pipeline components, and joint accessories must be
inspected on delivery to ensure that they are appropriately marked
and comply with the design requirements. Jacking pipes and pipe
joints must be marked with manufacturer, production date, nominal
size, appropriate ASTM standards, and production date. All pipe sec-
tions must be measured at each end for dimensional consistency
(diameters and lengths), and those outside of tolerance limits must be
marked and removed from the jobsite.
Extreme care must be taken when jointing unwelded, threaded,
or infused pipe to ensure that the joints remain free of any foreign
materials. Relatively small particles of foreign material can cause
joint leaks, especially during high-pressure testing. Pipe joints using
rubber gaskets are especially sensitive to contamination by any loose
earth. These gaskets require lubricant and must be placed in accord-
ance with the manufacturer’s recommendations. Preventing gasket
contamination must be part of the contractor’s plan. The lubricant
must conform to the manufacturer’s criteria because joint failures
have occurred when certain types of rubber were attacked by the
chemistry of improper lubricants.