Pig retainer is mainly used for pigging operations of submarine pipelines, which are more than 1,500 meters underwater. By rotating the handle of the manipulator, the pig lock pin is extended into the pipeline to block the pigging ball and prevent the pigging ball from moving in the pipeline.

The body flange of the pig retainer is designed with two grooves (red coating) up and down. When the pig retainer is working, the indicator ring will move back and forth with the rotation of the handle. The position of the groove is the limit of the movement of the indicator ring. After the pig retainer is installed on the pipeline system, it will improve the efficiency of pipeline transportation, reduce the corrosion of the inner wall of the pipeline, and prolong the life of the pipeline, and the application range will become wider and wider. 

Design Code:

API 6A (ISO 10423), API 17D/H, ASME B31.8, ASME VII DIV. 2, PD 5500 and PED (Others available upon request)

Pressure Range:

6,000 PSI (414 BAR) , 10,000 PSI (690 BAR) and 15,000 PSI (1035 BAR)

Max Water Depth:


Working Principle:

The flange tube seat of the pig retainer is welded to the outside of the pipeline and then installed and fixed, and the handle is clamped by the manipulator to rotate, so that the threaded transmission pushes the pig lock pin out to block the pigging ball.


In order to simulate the subsea working conditions, different parts are made of different materials, such as carbon steel, dual-phase steel, aluminum bronze, stainless steel, etc. In addition, anti-corrosion coating and lubricating coating are added; In order to facilitate user to operate through the screen, different colored coatings are used for easy identification. (refer to the picture)


  1. The product design and application are relatively mature, and the product quality is reliable.
  2. Good ROV operability, switch indication observation can be realized underwater, and the operating torque of the pig retainer is within the operating capacity of the ROV manipulator.
  3. Considering the strength of the product, the trapezoidal thread drive is used to realize it;
  4. The filter device is used to prevent impurities such as sediment and algae in the seawater from entering the product and thus affecting the transmission effect.
  5. Adopt special sealing ring (GlydRing) to ensure the reliability of sealing.