Trouble Shooting

Best Practices – 11th in the Series

Trouble Shooting– CIPP Lining Lining & Calibration Material

  1. HOLE IN LINING OR CALIBRATION MATERIAL
    1. Patch materials include Tear-Aid ™ product to cover the hole or welding on a patch. The product contains an adhesive in two versions. One for PVC coatings and one for all other plastic coatings. If unsure of the type of coating your liner tube uses, contact us for guidance. Heat fused patch material. You can weld on a patch to the material prior to wetting it out. Use PVC material for PVC coated lining material and TPU for polyurethane-coated liner. We do not have a silicon heat patch.
    2. If the lining material is saturated with resin and there are too many holes in the material you could pull the leaking liner into a calibration tube and invert them together.
      • Do not prepare the knot until the liner and calibration tube is inverted to the half-way point.
      • To prepare for this have all materials needed for the knot including duct tape, clamps, torque wrench, pull strap, and hose if heat curing applicable.
      • When the tailpiece approaches the end of the inversion unit, prepare the knot and feed the last half through the unit.
    3. If the hole is in the calibration tube, you may use the same options listed above for repairing the hole(s). If the calibration tube is too damaged for the installation, use replacement material. Pre-inspection of the liner and tube are critical to ensuring success.
  2. LINING MATERIAL STOPS MOVING DURING INVERSION
    • First try pulling the liner back a couple of feet if you are in the first ½ of the inversion, add more pressure and volume and try slamming the liner past the sticking point in the pipe.
    • If that a didn’t work, add a couple of gallons of water to the nose of the liner to round out the leading edge, repeat steps in a and try again.
    • Third, the attempt is to place a soft end on a high-speed cable machine and try pushing it through the un-inverted liner to the nose and try pushing the liner past the stopping point.
    • Forth attempt is to pull the liner out, invert a pre-liner into the pipe. If the pre-liner goes, attempt to reinvert the liner
    • If the liner is past the ½ waypoint and stops without fully inverting, insert a hook retriever and pull the liner out. Reinspect the line and if no obvious obstructions, re-attempt the inversion.
    • Check time. If you are getting close to the resin kicking off, pull out the liner and abandon it. Recheck the line and see what the inversion issues were that stopped the successful inversion of the liner.
  1. CALIBRATION LOSES PRESSURE
    1. Check Air/Water Supply and trying reinflation
    2. Replacement procedures to perform if the calibration tube fails
      • Leave calibration tube in place inside the pipe. It will lay at the bottom of the pipe
      • Prepare another calibration tube
      • Shoot in the new calibration tube OVER THE TOP of the tube lying in the bottom of the pipe. Not through the center of it.
      • Inflate the new calibration tube and cure as normal.
      • After cure, remove the new calibration tube first. Then the failed tube second. Inspect the pipe.
  2. LINER BUCKLED AFTER CALIBRATION TUBE REMOVED – This event occurs when the liner isn’t cured to a point it can stand on its’ own and can’t resist the pressure exerted by the live and dead load on the pipe. (Weight of soil, water, and traffic. Shark fins are typical evidence of this condition although a fully collapsed liner may also occur.
    • If you can thread a new calibration tube through the collapse that contains pull strap and recirculation hose it may be possible to heat the liner and round it out while it achieves a better level of cure.
    • As resin cures, it achieves a point that is closer to the HDT or heat deflection temperature of the resin. For example, the fully cured heat deflection temperature of our QP 60 resin is 250F. This resin while not fully cured may see any temperature of HDT between the percentage of cure and the 250F. If the resin achieved an HDT of 180F, by raising the temperature above 180F will allow the resin to “round out” and cure
    • The longer you wait the more the resin cures and the higher the HDT temperature becomes, so addressing this issue sooner rather than later is better.
    • The temperature to fully heat and reshape the resin usually takes longer than the initial cure so 4 hours or more of higher temperature may be needed to “re-round” the pipe.
    • If the cured tube is too cured to “re-round” excavation of the collapse may be needed as a last resort.

Resins

Resins – There are 3 resins considered for use for the CIPP process. They are polyester, vinyl ester, and epoxy. These resins can be formulated to cure at faster rates and some formulations require heat to initiate the curing of the resin. Below are the best practices to work with resin for the purposes of CIPP lining.

  1. Test resin to prove viability, cure times, and quantities needed for the job. Small batch samples of resin, particularly older resins should be mixed and tested to see if the actual cure times match the manufacturers recommended cure times. If they don’t the resin may still be viable but the initiation and cure times may drift from published data.
  2. Our epoxy resin comes in several formulations that pertain to work/cure times. 3 of the formulations hardeners may be mixed together resulting in changes in work/cure time. An example would be to mix ½ of our 60 minutes with ½ of our 30-minute resin resulting in a formula that will provide work/cure times in between the published values of the two. So they are mixable without regard to changing the standards set in ASTM F-1216 and ASTM F-1743.
  3. If your liner isn’t curing
    • Add time to your expected curing – ground temperature may be different than expected
    • Add heat to assist the curing process
    • If neither of these options was tried and failed, remove the material and dispose of it
  4. Resin washes out resulting in a portion of the liner not curing and appearing to not contain any resin.
    • If water from a tie-in or groundwater infiltration has washed away the resin, you can apply a patch over the top of the liner that is missing resin and cure it.
    • Use the same material for the patch as the liner
    • Use pre-liner to prevent future washout conditions when tie-ins and/or groundwater is involved.
  5. Concern that the presence of water will wash away your resin
    • Used calibration tube is always a resource to use as a pre-liner to separate groundwater or water from tie-in appliances from washing away the resin
    • If after CCTV inspection the water volume appears greater than the ability of the cure pressure to prevent water from affecting the finished product you can do the following
      • Apply grout to the areas of infiltration that area grout that swells and plugs water leak. Acrylamide ground is one such plug
      • Perform a point repair with a patch cured at 30psi to stop the infiltration
      • Excavate the area where the water is coming in and install a temporary pump to relieve the groundwater condition.

Pipe Conditions Affecting Jobs

  1. Water Infiltration/Inflow – addressed with the solutions above
  2. Broken or missing sections of pipe
    1. Our CIPP solutions provide a fully stand-alone pipe so missing or fully deteriorated pipe conditions. A pre-liner through the pipe missing sections or fully deteriorated pipe will allow around the restrained pipe to be formed in place when the line through
    1. Remove sections of clay tile and other obstructions from the pipe as the liner will form itself to any profile that is in the pipe. Poorly cleaned pipe and debris left in the pipe will be mirrored in the newly installed liner
  3. Missing invert in pipe worn away over time can be mitigated by installing a pre-liner and then lined over
  4. 90’s & 45’s

Compressor Failure During Installation

  1. Check for the following
    • Fuel
    • Air
    • Spark/Compression
    • Air Valve Obstructions/Closure
  2. If the unit is not able to complete the installation you have options
    • Fill the line with water to within 1’ of the nozzle
    • Connect your small compressor to the airport (make up an adaptor in advance for the connection from quick connect to Chicago air fitting for this purpose)
    • Set the pressure valve to 20 psi on the air pressure/volume gauge
    • Bump the ball valve open and add a pressure burst to the liner
      • You may have to hand feed material into the Quik Shot™ to get the liner to invert
      • Eventually, the weight of the water will begin pulling the liner through the unit provided you are installing from upstream to downstream
      • This process won’t work for shooting uphill
  3. If the small compressor isn’t operable you can attempt these methods to salvage the liner
    • Connect the inversion compressor if available and cure with that unit
    • Fill the calibration tube full of water allowing the weight of the water to hold the liner rounded out
      • You won’t circulate the water but it will cure at the ambient temperature rate
      • Monitor the water level to keep it full during the curing process

Calibration Roller Issues

  1. Rollers not parallel to each other
  2. Rollers have accumulated hardened resin on the rollers
    • Keep rollers clean as resin build-up will not give you proper “wet out” thickness in areas of buildup
    • Remove uncured resin with acetone
    • Grind off the hardened resin with grinder using care to not wear roller out of round
  3. The electric roller doesn’t operate
    • Check electricity
    • Check fuses
    • The motherboard is in the control box may be defective and need replacement

Quik Shot™ Issues

  1. Unit won’t invert liner
    1. Ensure you’ve applied enough lubricant to the liner coating. Too little lubricant will not free coating surface from sticking to itself
    2. Confirm that the gasket is sealed to the stiffener plate by sliding a credit card between the gasket and stiffener plate. If the credit card doesn’t detect a seal it will pass through.
      • Disassemble the cradle, gasket and stiffener plate.
      • Inspect the plate to ensure it’s true and not warped
      • Inspect the gasket to see evidence of the seal imprinted on the gasket
      • Excessive air exhausting out the sides of the Quik Shot ™ is a telltale symptom of the gasket not sealed
    3. Check the Ell brackets for proper fit
      • Over tightening the ell brackets may warp the stiffener plate and prevent the stiffener plate from sealing to the gasket
      • Check the alignment of the gasket, stiffener plate and gasket to see that they are seated in their correct positions
    4. Try inverting liner above ground. If that works your pipe condition is preventing the flow of liner through the gun
    5. If the above internal issues won’t allow the unit to invert then check the external items
      • Air Compressor not producing enough pressure or volume
      • The pressure regulator is not allowing flow at the capacity needed to process the liner
      • Check the Airball valve to ensure it fully opens
      • Check the air delivery hose for obstructions

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