Apache MDK bi-directional pigs are designed for use in long-run pipeline construction applications during the hydrostatic test stage. Designed to travel in either direction, the operator can fill the line with water and displace the water without removing the pig. The MDK mandrels are engineered to easily be adapted to a cleaning pig by the addition of flat steel wire brushes.
MDK pigs have both an inner mandrel and outer mandrel. The MDKs dual mandrel is favoured by contractors, as the inner mandrel withstands the battering inherent during construction phases, while the outer disc carrying mandrel remains untouched. The pigs are equipped with durable guide discs, one at each end. They provide a positive centring affect which allow the four sealing discs in the centre to effectively seal during the displacement period. Apache bumper noses are also included with MDK pigs. They prevent damage of expensive in-line auxiliary equipment. Transmitter cavities and handling hooks are other standard features on the MDK.