Customer Challenge:
During the fabrication stage, attaching wires to a pipeline is simple, as they can be easily soldered on. Once buried and underground though, this method is risky and often prohibitive given the volatile nature of the pipeline’s contents. In this situation, an alternative such as a cold solder becomes necessary to avoid the risk of sparks and possible ignition.
Wire attachment to underground pipelines facilitates connection to above-ground cathodic protection systems that extend the life of pipelines by inhibiting corrosion. Specifically, a metal jig with a wire harness attached is adhered directly to the pipeline with a conductive adhesive. A magnet within the jig holds it to the pipeline temporarily until the epoxy cures.
Once cured, electrical current can be run from an above-ground DC power supply directly to the pipeline. For this customer, the challenge was to find an adhesive substitute for solder that cured at room temperature, adhered strongly to metal and imparted good electrical conductivity.
KEY CUSTOMER REQUIREMENTS
- Room temperature cure
- Good electrical conductivity
- Good adhesion to metal surfaces
SOLUTION
MG Chemicals 8331D is a 2-part electrically conductive epoxy that can be used as a substitute for solder. The epoxy system cures at room temperature and adheres to many substrates including most metals, plastics, glass and wood. The mixed epoxy has a consistency that makes it easy to spread over surfaces. It contains silver, thus is highly conductive and helps to carry current. The cured epoxy is very durable and can survive under harsh conditions for many years without performance loss.
CONCLUSION
The volatile contents running through underground pipelines make practices such as welding or soldering prohibitive to attach wires. These wires connect to DC power sources above-ground that provide the pipelines with cathodic protection which extends the lifetime of the pipes by slowing corrosion. Electrically conductive epoxy such as 8331D allow wires to be attached that do not carry the risk of ignition. The cured bond is electrically conductive and can carry currents from DC power sources directly to the pipe.
