Modular pressure clylinder for a downhole tool

A modular pressure cylinder for a downhole tool, comprising:

• an active mandrel tube having a central passage and active mandrel tube fluid ports that provide fluid communication between the central passage and an external periphery of the active mandrel tube with active mandrel tube axial grooves in an outer periphery thereof, the active mandrel tube axial grooves respectively being in fluid communication with the active mandrel tube fluid ports to ensure fluid communication between the central passage and respective pressure cylinder fluid ports of the modular pressure cylinder while the modular pressure cylinder is urged along an axis of the active mandrel tube;
• and
• a modular pressure cylinder that reciprocates on the active mandrel tube, the modular pressure cylinder including at least two interconnected pressure cylinder modules having interconnected pressure cylinder walls and pressure pistons respectively having pressure cylinder male coupling sleeves and pressure cylinder female coupling sleeves that interconnect the pressure pistons, the pressure pistons having pressure piston seals that respectively provide a fluid seal against the respective pressure cylinder walls, the pressure pistons reciprocating within pressure cylinders defined by the interconnected pressure cylinder walls and the interconnected pressure cylinder male and female coupling sleeves, the interconnected pressure cylinder male and female coupling sleeves including pressure cylinder fluid ports that permit pressurized fluid flowing through the active mandrel tube to flow into the pressure cylinders and urge the interconnected pressure cylinder walls and the interconnected pressure pistons to move in opposite directions along an axis of the active mandrel tube, and the pressure cylinder walls respectively including pressure cylinder pressure equalization ports to equalize fluid pressure behind the respective pressure pistons.