Product Introduction
This full set of replacement parts includes all critical components to rebuild and maintain HG139 and HG138 skidding cylinders, covering structural parts, hydraulic sealing kits, guidance components, fasteners, and auxiliary hydraulic accessories. These are direct-fit OEM equivalents, not generic aftermarket parts—each piece is machined to match the original design specs, so installation requires no modifications, and performance matches the factory-built cylinder perfectly. The lineup covers both HG139 small-bore and HG138 large-bore skidding cylinder configurations, making it a one-stop sourcing solution for rig skid system maintenance.
Function Specifications
- Structural Actuation Parts: Cylinder bodies (HG139-01, HG138-01) form rigid pressure vessels; pistons and piston rods convert hydraulic pressure into smooth linear thrust with 95%+ force efficiency; oscillating bearings (GE90ES) enable flexible mounting alignment for rig skid movement.
- Hydraulic Sealing Components: Piston seals (K08-D, K01-P) and step seals (JF-120) block internal fluid leakage; O-rings (GB3452.1-92, GB1235-76) seal joint gaps; dust rings (CK-120, A01) keep mud, dust, and debris out of the cylinder bore to prevent premature wear.
- Guidance & Retention Parts: Support rings and guide rings reduce friction between moving parts; retainer rings and snap rings lock internal components in place under heavy cyclic loads; locking screws and allen bolts secure external assemblies to prevent vibration-induced loosening.
Structural Characteristics
All skidding cylinder parts are built for rugged oilfield use: cylinder bodies and piston rods use quenched-and-tempered 40Cr alloy steel with 55–62 HRC hardness to resist bending and scoring; sealing elements use oil-resistant, high-pressure polyurethane and nitrile rubber with less than 10% compression set at 100°C; fasteners meet GB/T industrial standards for shear and tensile strength, with spring washers to absorb vibration. Guidance sleeves are precision-honed for smooth rod movement, eliminating side loading that damages seals and rods.
Applicable Operating Conditions
These parts are designed to perform reliably in the extreme conditions of drilling rig skid systems:
- Hydraulic operating pressure range: 10MPa to 21MPa (standard for rig skid actuation)
- Ambient temperatures: -20°C (cold climate rigs) to 65°C (desert/offshore drilling sites)
- Dusty, muddy, and high-humidity rig floor environments
- Continuous 24/7 operation with frequent forward/reverse cylinder cycles
- Onshore and offshore drilling rig skidding, wellhead positioning, and pipe handling equipment
Maintenance & Servicing Suggestions
- Pre-Installation Checks: Verify part numbers against cylinder technical drawings; inspect piston rods for scratches or bends; check seals for brittleness, cracks, or deformation before fitting.
- Seal System Care: Replace all sealing kits every 8,000 operating hours; lubricate sealing surfaces with hydraulic oil during assembly; avoid using sharp tools that can nick seals during installation.
- Wear Component Inspection: Check guide rings and support rings for wear every 3,000 hours; replace if thickness drops below the rated tolerance; clean cylinder bores thoroughly to remove abrasive particles.
- Fastener & Retainer Maintenance: Re-torque allen screws and locking bolts to specified values every 5,000 hours; replace deformed spring washers and worn retainer rings immediately.
- Post-Repair Testing: Conduct pressure testing at 1.25 times working pressure to check for leaks; test full cylinder stroke to ensure smooth movement; monitor for abnormal noise or friction during operation.
We supply the following spare parts:
| Item | Part No | Name |
| 1 | HG139-01 | Cylinder body |
| 2 | GB/T78 | Tighten screw M6* 10 |
| 3 | HG139-02 | Piston |
| 4 | CY166-94 | Support ring ZD250B |
| 5 | CY143-2004 | Rectangle seal UF-0230 |
| 6 | GB3452.1-92 | O ring 206*7 |
| 7 | GB1235-76 | O ring 95*3.1 |
| 8 | HG139-03 | Piston rod |
| 9 | HG139-04 | Slide Sleeve |
| 10 | CY166-94 | Backup ring ZD125B |
| 11 | CY127-1997 | Step seal JF-120 |
| 12 | GB3452.1-92 | O ring 125*5.3 |
| 13 | GB1235-76 | O ring 230*5.7 |
| 14 | HG139-05 | Hole clamp |
| 15 | HG139-06 | Retainer ring |
| 16 | GB894.1-1986 | Retainer 210 |
| 17 | CY115-85 | Seal Ring d120 |
| 18 | CY129-1997 | Dust ring CK-120 |
| 19 | GB1152-89 | Lubricating cap M10*1 |
| 20 | HG139-07 | Rod Head |
| 21 | GB893.1-1986 | Snap ring for hole 130 |
| 22 | GE90ES | Oscillating bearing |
| 23 | PPT-3 | Air discharging pressure test connector |
| 丨te m | Part No | Name |
| i | GB/T825 | Lifting bolt M36 |
| 2 | HG138-01 | Cylinder body |
| 3 | PPT-3 | Air discharging pressure test connector |
| 4 | GB/T894.1 | Retainer 200 |
| 5 | HG138-02 | Clamp cap |
| 6 | HG138-03 | Shaft clamp |
| 7 | K08-D(480 x 455.5 x 8.1) | Piston seal |
| 8 | F01(480 x 475 x 25) | Guide ring |
| 9 | K01-P(480 x 456 x 18) | Piston seal |
| 10 | GB3452.1-92 | O ring 190 x 5.3 |
| 11 | HG138-04 | Piston |
| 12 | HG138-05 | Piston rod |
| 13 | GB3452.1-92 | O ring 462 x 7 |
| 14 | HG138-06 | Slide Sleeve |
| 15 | HG138-07 | Capping |
| 16 | GB/T78 | Holding Screw M10 x 12 |
| 17 | S09-E(250 x 270.5 x 8.1) | Rod seal |
| 18 | F01(250 x 255 x 25) | Guide ring |
| 19 | S01-P(250 x 270 x 14) | Rod seal |
| 20 | A01(250 x 265 x 6.5/13) | Dust ring |
| 21 | GB/T70.1 | Allen screw M16 x 30 |
| 22 | GB/T93 | Spring Washer 16 |
| 23 | HG138-08 | Ball Cover plate |
| 24 | HG138-09 | Ball Substructure |
| 25 | Z2S16 | Bidirectionallock |
| 26 | HG033-09 | Valve cap |
| 27 | GB/T70.1 | Allen screw M6 x 140 |
| 28 | GB/T70.1 | Allen screw M10 x 140 |
| 29 | GB/T93 | Spring Washer 6 |
| 30 | GB/T93 | Spring Washer 10 |
| 31 | GB1235-76 | O ring 26 x 2.4 |
On-Site Skidding Cylinder Fault Repair Cases
Case 1: HG139 Cylinder Hydraulic Leak from Worn Step Seal
A drilling rig’s HG139 skidding cylinder leaked hydraulic fluid externally, causing inconsistent skid movement. The issue was traced to a worn JF-120 step seal (CY127-1997) and a damaged 125*5.3 O-ring, which failed due to long-term friction and pressure cycling. Replacing the worn seal and O-ring, plus cleaning the piston rod surface, eliminated leaks and restored stable cylinder actuation.
Case 2: HG138 Cylinder Rod Scuffing & Rough Movement
An offshore rig’s HG138 skidding cylinder developed rough, jerky movement with increased resistance. On-site inspection found the guide rings (F01) were severely worn, allowing the piston rod to rub against the cylinder bore and cause scuffing. Installing new guide rings, a dust ring (A01), and polishing the rod surface fixed the friction issue and restored smooth operation.
Case 3: HG138 Cylinder Internal Component Displacement
A land rig’s HG138 skidding cylinder lost thrust power mid-operation, caused by a failed GB/T894.1 retainer ring that held the piston in place. The broken retainer let the piston shift internally, disrupting pressure transfer. Swapping the faulty retainer ring, re-seating the piston, and replacing associated O-rings brought the cylinder back to full thrust capacity.
Frequently Asked Questions (FAQ)
| Question | Answer |
| Are these parts compatible with both HG139 and HG138 skidding cylinders? | Yes, this parts list is split to fit HG139 and HG138 models specifically—each part is labeled for its matching cylinder model, ensuring exact fit and no compatibility errors. |
| What is the maximum pressure rating for these sealing components? | All seals, O-rings, and support rings are rated for a maximum continuous operating pressure of 21MPa (3045PSI), meeting industry standards for drilling rig hydraulic skid systems. |
| How do I identify which seal or ring my cylinder needs? | Cross-reference the part number on your worn component with this list, or match the dimensions (e.g., O-ring diameter, seal width) to your HG139/HG138 cylinder’s technical specifications for accurate replacement. |
Procurement Guidance & Closing Statement
For teams maintaining HG139 and HG138 skidding cylinders on drilling rigs and wellhead equipment, this spare parts collection provides a fully compliant, quality-verified sourcing solution that removes guesswork from procurement and repairs. Backed by strict hydraulic manufacturing standards and exact OEM part matching, these parts reduce installation time, eliminate compatibility risks, and provide a clear technical benchmark to resolve cylinder failures fast. Whether stocking for routine preventive maintenance, emergency field repairs, or full cylinder overhauls, these HG139 and HG138-specific parts keep your skid systems operating safely, efficiently, and in line with industry requirements. Secure the precise cylinder bodies, seals, rods, and fasteners you need to keep your skidding cylinders running reliably and avoid costly rig downtime.
