Silicone Expansion Bladders
Fenner Precision Bladders are used in the repair of worn and damaged main line and lateral feed sewer pipes, portable water pipes, oil and gas pipes, and more.
Fenner Precision has worked with the leading “no-dig” repair companies to develop fabric reinforced silicone expansion bladders to make the no dig process work efficiently. Prior to starting the repair process, the pre-pregs are positioned over the Fenner Precision expansion bladders. The bladder and epoxy repair material are turned inside out and collapsed into a bellows shape. This preparatory work is normally done above ground. The assembled repair material and expansion bladder are then lowered through a manhole into the sewer. Hot water is circulated through the expansion bladder. This causes the bellow to expand and position the pre-preg inside the full length of the damaged pipe.
Once the repair material is in place the expansion bladder is further expanded to hold the repair material up against the inside of the damaged pipe while it cures from the heat of the circulating hot water.
Once the cure process is completed the expansion bladder is deflated and withdrawn from the sewer ready for use on another occasion.
Silicone Expansion Bladders offer many distinct advantages and benefits, which are:
- Non-stick and reusable (easy withdrawal and multiple use), up to 15 uses per bladder.
- Excellent UV and ozone resistance.
- Good chemical resistance.
- Highly durable over a wide temperature range (-60°C to 200°C).
- Excellent release properties.
- Flexible (capable of turning inside out).
- Section thickness of only 2mm (0.08”) facilitates good heat transfer and reduced cure times.
Bladder Material Properties
- The bladders are a combination of specially selected knitted polyester fabrics and silicone rubber.
- Standard length range of 30m to 200m (100ft to 65ft).
- Standard diameter range of 76mm to 915mm (3” to 36”).
- Standard thickness of 2mm (0.08”).