PCE Hydraulic Stuffing Box with Grease Injection

Description

PCE Hydraulic Stuffing Box with Grease Injection

Technical Description

The Hydraulic Stuffing Box with Grease Injection is an advanced pressure control component used primarily in high-pressure slickline operations (>5,000 psi). Unlike a standard stuffing box that relies solely on mechanical “squeeze” from rubber packings, this tool creates a hydraulic seal by continuously injecting high-viscosity grease into a series of tight-tolerance flow tubes.

Key Technical Specifications and Operation

• Function: To create a liquid-seal barrier around the slickline wire.¹ The injected grease fills the microscopic gaps between the wire and the flow tubes, providing a superior seal compared to dry elastomers.

• The Grease Seal Mechanism: Grease is pumped into the chamber at a pressure slightly higher than the wellbore pressure. This ensures that any leakage consists of clean grease moving downward into the well, rather than wellbore fluids escaping upward.

• Lubrication and Protection: Beyond sealing, the grease acts as a continuous lubricant for the wire, significantly reducing friction during high-speed runs and coating the wire in a protective layer to prevent corrosion.

• Flow Tubes: The core of the tool consists of several precision-machined flow tubes. These are “sized” to the specific wire diameter (e.g., 0.108″ or 0.125″) with a clearance of only a few thousandths of an inch to maximize the effectiveness of the grease barrier.

• Hydraulic Packing Backup: Most grease injection heads also feature a standard hydraulic packing nut at the very top as a final secondary seal and to wipe excess grease off the wire as it exits.

Customization and Materials

• Multi-Port Injection: High-spec models feature multiple injection ports to ensure an even distribution of grease across long flow-tube sections.

• Flow Tube Sizing: Tubes are interchangeable and must be matched exactly to the wire diameter to maintain the seal integrity.

• Materials: Body components are typically manufactured from 4140 Alloy Steel or 17-4 PH Stainless Steel. All internal components are NACE MR0175 compliant for sour service.

Critical Parameters