Bi-directional pigs are constructed with a central steel body onto which urethane discs are mounted, secured by tie rods fixed to flanges welded to the body.
Bi-directional pigs are used for a wide range of applications, including commissioning, dewatering, cleaning, calibration, and product separation. Depending on the model, these pigs are capable of negotiating internal diameter reductions of up to 15–20%.
The standard configuration includes two guide discs and four polyurethane sealing discs. The guide discs are manufactured with a diameter equal to or slightly larger than the pipeline internal diameter, while the sealing discs are oversized to ensure effective sealing. The guide discs maintain the pig centered within the pipeline, support its weight, and remove deposited debris. The sealing discs provide sealing and light cleaning action and are thinner than the guide discs to increase flexibility.
All bi-directional pigs can be adapted to multiple operating conditions through the installation of various accessories, including:
