Displacement Pig (Disc Type) - Steel Mandral Pigs - Pipeline Pigs - Pipeline Pigging & Equipment

Pipeline Pigging · Steel Mandrel Pigs

Displacement Pigs
Disc Type

Bidirectional carbon steel mandrel pigs that seal equally in both directions of travel, for hydrostatic testing, dewatering, and product separation in 2" through 48" lines.

Steel Mandrel Pigs

Applications & Features

Applications

Purging air from pipelines prior to hydrostatic pressure testing
Dewatering after hydrostatic testing to restore the line to service
Displacing hydrocarbons from a pipeline section ahead of maintenance or repair work
Recovering natural gas liquids (NGLs) from gas transmission lines
Product separation in multi product pipelines to prevent contamination
Inhibitor and chemical treatment batch placement
Bidirectional operation, where the disc design seals equally in both directions of travel

Features

Carbon steel mandrel body with easily replaceable polyurethane discs
Disc geometry provides bidirectional sealing, so the pig operates equally well regardless of direction of flow with no front or back orientation required
Available in two disc (BGD-2) and four disc (BGD-4) standard configurations
Models 2" to 8" are center rod type, 10" and up are bolting pattern configuration
Available in sizes 2" through 48"
All discs are field replaceable, restoring the pig to like new condition
Optional gauging plate machined to customer specifications
Can be fitted with guide, sealing, and spacer discs for enhanced sealing in demanding applications

Bidirectional by Design

Unlike cup type pigs, which are directional and must be launched facing the correct way, disc type displacement pigs seal against the pipe wall equally in both directions of travel. That makes them the preferred choice when bidirectional operation is required, such as purging a pipeline section from either end, reversing a pig during a stall, or operating in systems with reversing flow. The flat disc profile also allows passage through a wider range of fittings and check valves than cup configurations.

Available Models

BGD-2Sizes 2"–48"	Two disc bidirectional displacement pig. Carbon steel body with two easily replaceable polyurethane discs. Center rod type in 2" to 8", bolting pattern in 10" and up. Optional gauging plate available.
BGD-4Sizes 2"–48"	Four disc bidirectional displacement pig. Same construction with four polyurethane discs for increased sealing redundancy and improved product separation efficiency. Center rod type in 2" to 8", bolting pattern in 10" and up. Optional gauging plate available.

Available Options

Gauging plate in aluminum or steel, varying thickness, slotted versions available
Carbon steel, stainless steel, or aluminum mandrel body
Disc elastomer options: neoprene, viton, EPDM, Buna-N, and other compounds for chemical compatibility
Additional guide, sealing, and spacer discs for enhanced sealing capability
Cup addition or substitution for combination cup and disc configurations
Transmitter or pinger cavity for pig tracking
Magnets for ferrous debris collection or magnetic detection
Customized lengths and diameters for special pigging applications

Need displacement pigs for hydrostatic testing, dewatering, or product separation? Contact us for pricing and availability.