The ED pigs are bi-directional in design and used primarily for air and water displacement applications during the pressure test stage of construction. Designed to travel in either direction, the operator can fill the line with water and displace the water without removing the pig.
The ED version, with a combination of 4 sealing and 2 guide discs, offers a sealing arrangement suitable for separation of dissimilar fluids or for dewatering during hydrostatic testing. Sealing discs experiencing wear can reverse direction without compromising sealing characteristics. Simple replacement of a disc with a circular wire brushes (in EDR model) enhances the versatility of the ED series.