Sucker rod displacement pump NNVD

Sucker rod displacement pump NNVD differs from conventional one by its design – it has a plunger with hollow rod and leak-proof seal of hollow rod. In contrast with conventional SRP plunger of NNVD has no impact of tubing fluid column, fluid from plunger flows in hollow rod but not in the space above the plunger. If compare NNVD pump with conventional SRP or ESP it has the same drive, quantity of strokes and flow rate but its setting depth is up to 2700 meters.