Bio-Seal E206 Seals & Reinforces a Large Heated Pipeline
DESCRIPTION
THE CHALLENGE: Utilities and communities which distribute heat through steam pipes face a repair challenge when perforations have to be repaired. A new, high temperature epoxy resin the Bio-Seal E206 was created to address this requirement.
THE SOLUTION: BIO-SEAL E206 is a solvent-free epoxy resin with properties to make it uniquely suitable for this application. An extremely attractive property is that the BIO-SEAL E206 resin will semi-cure to a hard and tack-free condition overnight. High heat resins almost
always require some post-curing to at least 150°F/66°C in order to get an initial cure to make them possible to handle. BIO-SEAL E206 cures to a hard surface which can then be easily handled into an oven or left in place to cure when heated in service. In order to generate full properties it is necessary to heat to over 200°F/93°C for at least two hours. Maximum glass transition temperature is attained after heating to 302°F/150°C for two hours.
INSTALLATION ON 32” STEAM PIPE: This was a test installation for a private utility in Europe. Before specifying the BIO-SEAL E206 this utility required its own independent testing. To do this it created a test cell comprising a length of heated and insulated 32” pipe
which could be pressurized to 26bar/380psi and heated to 356°F/180°C. The photographs below show the progression of the test. Bio-Seal E206 was thickened with a mineral fiber to create a putty-like material to fill the simulated penetration.
Bio-Seal E206 is supplied as a yellow base and a blue curing agent which combine to make an attractive green mixture. Consistency is ideal for brush, roller or spatula application.
Impregnation is accomplished by spreading onto the fabric placed on a plastic covered table. First apply a roller coat of BIO-SEAL E206 to the plastic in order to both hold the fabric into position and to ensure proper impregnation of its underside. The BIO-SEAL E206 is then
poured onto the fabric and evenly spread using a plastic straight-edge as shown. When evenly spread the fabric is rolled onto a dowel to facilitate application to the pipe. After application the carbon fiber is completely saturated however there is no excess of resin.
The stricture wrap is a stretchy polyolefin film which makes the composite as dense as possible. This is also very useful when the repair composite is applied to nonplanar surfaces such as around flanges, “L” bends and T’s. After the BIO-SEAL E206 the stricture film has absolutely
no adhesion and may be easily unwrapped to leave a smooth, glossy surface.
DISCUSSION: The test unit was heated and pressurized for six months. Over this period the BIO-SEAL E206 resin develops a dark exterior. At temperatures as high as 50 0°F/260°C this darkening becomes almost black. Lab work at TFT has shown that good properties are retained to a maximum of 500°F however normal recommendation is to use at a more conservative temperature of 450°F/232°C.
RESULT: After six months of testing at 356°F/180°C the complete installation remained in perfect condition with no leakage or other deterioration
