Steam Cure Liner Installation Process has become commonplace for installing 6" to 15" diameter CIPP liners. Steam is used in conjunction with pressurized air that inflates the liner against the host pipe and distributes the steam from one end of the liner to other. When using a steam cure, the liner can be positioned within the hose pipe by the water inversion method or with the use of an air inverter (shooter). If the winch in place method is used, a double coated liner is required.
Most CIPP liners use thermosetting or heat activated resins. Heat, through water or steam must be transferred evenly throughout the liner to properly cure the resin. Heat transfer must be monitored to prevent over heating the resin (called resin boil) which can weaken the finished liner.
Use of steam cure is normally faster than hot water cure, as steam heat transfer is quicker. Steam cans are attached at both ends of the liner with pressurized steam-air mixture introduced at one end and allowed to discharge at the other end. Once the cure has completed, pressurized air is allowed to flow through the liner to cool the liner. Set up of a steam cure system is quicker than a hot water cure system.
The pictures below show the Steam Curing Method where pasteurized air is used to inflate the CIPP liner tight against the host pipe wall while delivering steam for the resin cure. Mobile high volume steam generators or steam boilers are used to produce steam that is introduced into the pressurized air stream. The pressurized stream-air mixture is connected to one end of the CIPP liner through a steam can. At the opposite end of the CIPP liner, a steam control station ("B" Station), and a steam discharge muffler is attached. The "B" Station is used to regulate the internal air pressure within the CIPP liner and the flow of the steam-air mixture through the CIPP liner. The steam discharge muffler is used to suppress noise and safely disperse steam to the environment. Upon completion of the resin cure or exotherm, the steam source is shut off but the pressurized air flow is maintained through the CIPP liner. Air flow is used to gradually cool the liner as per the resin to prevent shrinkage.
Hot Water Cure is easier to control temperature changes, both during temperature ramp-up and cool down stages. A hot water cure system requires the use of discharge hoses to be inserted within the un-cured liner. Discharge hoses are attached to the end of the liner during the inversion process, when the inversion process is complete - the discharge hoses are at the end of the liner. Using a high volume pump, water is drawn out of the inversion column and pushed through a hot water boiler to be heated. Heated water discharged from the boiler is forced through the discharge hose to the far end of the liner thus creating a water flow loop. Water temperature is gradually increased and evenly distributed throughout the liner over time. To cool the liner, the boiler is shut-off & cold water is added to the inversion column as the circulation pump continues to operate.
Using steam or hot water cures, installers must be aware of the chemical reactions within the liner. Fast Pipe Lining ships all liners with recommended inversion column height, water column cure height, liner pressure requirements and exotherm reaction temperatures. Installation guidelines assist installers in the field to properly to achieve a finished CIPP liner with the maximum tensile strength properties. Installation crews have the ultimate responsibility for attaining the maximum quality of every cured-in-place pipe.
Fast Pipe Lining provides ready to install CIPP liners using several different catalyzed resin systems for use with steam or hot water curing systems, all which conform to ASTM Standards.
As part of the wet-out process, sample material from CIPP liners is used to prepare flat plate test samples. Samples are compressed between two pieces of metal to the specified thickness then wrapped in polyurethane. Test samples are shipped with the related CIPP liner to the installation site where the sample is cured as part of the liner installation process. To cure flat plate samples, samples can be submersed in the inversion water column or placed with the CIPP liner for steam curing. For hoop test samples, Fast Pipe Liner can ship pre-cut plastic pipe sections for sample making at the time of installation, a time saving process for installation crews.
NOTE: All pictures, videos, designs and specifications are subject to change without notice.