2C03.12 Large Hydraulic Cylinder & 2C02.01().00 Ram Assembly

1. Core Purpose & Target User Segmentation

This comprehensive spare parts collection is exclusively engineered to fit FZ Series Ram BOPs (including FZ18-21, FZ18-35, FZ23-21, FZ28-35, FZ35-35, etc.)—the critical well control equipment widely used in onshore and offshore oilfield drilling, well completion, and workover operations. Its core purpose is to resolve the most common and costly operational pain points faced by drilling teams: hydraulic leakage, piston wear, ram actuation failure, seal degradation, and unplanned downtime—all of which threaten well safety, delay operations, and increase maintenance costs. Target users are segmented to address specific needs: drilling contractors operating FZ Series Ram BOPs, well service companies handling routine maintenance and emergency repairs, and E&P (Exploration and Production) teams working in harsh HPHT (High Pressure High Temperature), sour service (H₂S-containing), and high-contamination mud environments. For routine maintenance teams, we provide cost-effective seal and wear part kits to extend BOP service life; for emergency response teams, we offer direct drop-in replacement parts to minimize downtime; for technical teams, we supply detailed compatibility and troubleshooting guidelines to simplify on-site operations.

2. Product Description & Value Proposition

2.1 Product Introduction

The spare parts suite covers all critical components required for FZ Series Ram BOP maintenance and repair, including hydraulic actuation components (2C03.12/2C02.12 Large hydraulic cylinder, 2C02.01().00 Ram Assembly, 2C01.03.05 Boosting Piston), sealing systems (SKZF101.01H Y ring, 2C02.07H Flange Sealing Assembly, 100.97×5.33(ID×d) O-ring, C664-22 Backup ring, 300X5.3 O-ring), mechanical connectors & fasteners (2C01.14 Nut 1 1/2-8UN-2B, 2C01.13 Bolt 1/2-8UNx6 1/4, 2C03.16/2C02.16 Cylinder Cap Screw, M12x20 Socket head cap screw),structural components (2C03.06/2C02.06 Locking Axle Seat, 2C03.03.02 Connecting Plate, 2C03.03.04 Baffle Plate, C17.08.03 Stop block),piston components (2C03.11A/2C02.11A Main Piston, 2C03.11A-01 Integral Main Piston, 2C03.11B-01.00 Detachable Main Piston, 2C03.11B-01.01 Piston Rod), and specialized parts (2C02.11A-02 Hanger For Pipe rams, 2C02.11A-03 Hanger For Shear rams, 2C01.20 Plug Cock 1-8UNC). All parts are manufactured in strict compliance with API Spec 6A (wellhead equipment) and API Spec 16A (ram BOP) standards, with NACE MR0175/ISO 15156 certification for sour service compatibility, ensuring they meet the strict dimensional and performance requirements of FZ Series Ram BOPs. Backed by third-party testing and 8+ years of field validation, each part undergoes 100% dimensional inspection and pressure testing (up to 20.0 MPa proof pressure) before leaving the factory, with a field failure rate of less than 0.03% over 5 years of use. All components are direct drop-in replacements for original parts, eliminating the need for custom modifications and ensuring quick installation.

2.2 Function Description

Every component in this suite is designed to solve specific operational pain points, ensuring the reliable performance of FZ Series Ram BOPs:

• Large Hydraulic Cylinder (2C03.12/2C02.12) & Ram Assembly (2C02.01().00): Convert hydraulic energy into mechanical force to drive pipe rams and shear rams, enabling rapid closure (within 6 seconds at rated pressure) to seal the wellbore and maintain well control. These components solve the problem of slow or failed ram actuation caused by cylinder wear or internal leakage, which can lead to catastrophic well control incidents.

• Piston Components: Main Pistons (2C03.11A/2C02.11A) and Piston Rods (2C03.11B-01.01) transmit force from the hydraulic cylinder to the ram assembly, ensuring smooth, consistent movement. The integral (2C03.11A-01) and detachable (2C03.11B-01.00) main pistons offer flexibility for different maintenance needs, solving the problem of difficult piston replacement and reducing maintenance time by 40 minutes per repair.

• Sealing Systems: SKZF101.01H Y rings, flange sealing assemblies, O-rings, and backup rings create a tight, pressure-resistant barrier between dynamic and static interfaces, preventing hydraulic fluid leakage and mud ingress. For example, the 100.97×5.33 O-ring and C664-22 Backup ring (102.31X111.61X1.52) work together to resist extrusion under high pressure (up to 15,000 PSI), avoiding the common issue of seal failure that leads to unplanned downtime. The 300X5.3 O-ring is specifically designed for boosting hydraulic cylinders, solving pressure loss in critical actuation systems.

• Connectors & Fasteners: Nuts, bolts, and cylinder cap screws (e.g., 2C01.14 Nut 1 1/2-8UN-2B, 2C01.13 Bolt 1/2-8UNx6 1/4) ensure secure, leak-proof connections, withstanding vibration and torque during drilling operations—eliminating the risk of loose components that can cause system failure. Threaded components comply with UNC/UN standards, ensuring compatibility with original FZ Series BOP parts.

• Structural Components: Locking Axle Seats (2C03.06/2C02.06) secure the ram assembly in place, preventing unintended movement during operation. Connecting Plates (2C03.03.02) and Baffle Plates (2C03.03.04) provide rigid support for BOP stack components, solving the problem of structural loosening under dynamic loads. Hangers (2C02.11A-02/03) for pipe rams and shear rams ensure proper alignment, reducing wear and extending ram service life.

2.3 Structural Features

Our spare parts are engineered with durability and performance in mind, addressing the unique challenges of oilfield drilling environments and meeting API and NACE standards:

• Material Selection: Metallic components (hydraulic cylinders, pistons, connecting plates, fasteners) are forged from corrosion-resistant alloy steel (CRA) with heat treatment, achieving a minimum tensile strength of 820 MPa and hardness of HRC 23–33—meeting NACE MR0175/ISO 15156 requirements to resist sulfide stress cracking (SSC) and hydrogen-induced cracking (HIC) in sour service environments. Seals use high-quality elastomers (FKM, NBR, EPDM) tailored to their application: FKM seals (for Y rings and O-rings) withstand temperatures up to 200°C and resist chemical attack from drilling mud, while backup rings (C664-22) are made of high-strength PTFE to prevent seal extrusion. All elastomers have a Shore A hardness of 72–88, ensuring optimal compression and sealing performance.

• Precision Manufacturing: Hydraulic cylinder inner surfaces are honed to a surface roughness of Ra 0.2–0.35 μm, reducing friction and extending seal life by 14 months compared to standard cylinders. Threaded components (e.g., 2C01.14 Nut 1 1/2-8UN-2B) comply with KS Class 2 thread tolerance, ensuring a tight, secure fit with no galling. O-rings feature precision-machined gland dimensions with a tolerance of ±0.04 mm, ensuring a squeeze rate of 16–24% to prevent leakage under high pressure. Ram assemblies are manufactured with a stroke tolerance of 0–0.8 mm, ensuring precise alignment with BOP rams.

• Design Optimization: Large hydraulic cylinders include integrated pressure relief grooves to reduce stress concentration, preventing cracking under high pressure (up to 15,000 PSI). Main pistons are designed with lubrication grooves to minimize friction and heat generation, reducing wear and extending service life. Locking Axle Seats feature a robust, wear-resistant design to withstand repeated actuation, solving the problem of axle seat failure that can disable the entire ram assembly. Flange sealing assemblies (2C02.07H) are designed for easy installation, reducing maintenance time by 30% compared to standard seals.

2.4 Applicable Working Conditions

All parts are designed to perform reliably in the harshest oilfield environments, matching the operational requirements of FZ Series Ram BOPs (FZ18-21 to FZ35-105):

• Pressure Range: 2,000–15,000 PSI (compatible with API 6A PSL 3/4 and API 16A PR2 ratings), matching the working pressure of FZ Series BOPs (3,000–15,000 PSI) and ensuring reliable performance in high-pressure drilling operations.

• Temperature Range: -40°C to +200°C, making them ideal for arctic (Siberia, Alaska), tropical (Middle East), and HPHT (Gulf of Mexico) drilling environments. Seals retain flexibility at low temperatures (-40°C) to prevent hardening and cracking, and maintain integrity at high temperatures (+200°C) to avoid melting or degradation.

• Environment: Resistant to H₂S (up to 0.0006 MPa partial pressure), CO₂, saltwater, and drilling mud contaminants (sand, metal particles). Suitable for onshore drilling rigs (Permian Basin, Texas), offshore platforms (North Sea, South China Sea), and workover sites (Middle East), complying with sour service requirements for oil and gas production.

• System Compatibility: Direct drop-in replacement for FZ Series Ram BOPs (FZ18-21, FZ18-35, FZ23-21, FZ28-35, FZ35-35, etc.), and compatible with drilling equipment from Weatherford, Honghua (宏华), and Jereh (杰瑞)—eliminating the need for custom modifications and ensuring quick installation.

2.5 Maintenance & Care Recommendations

To maximize the service life of these spare parts and ensure FZ Series Ram BOP reliability, our engineering team (with 15+ years of oilfield BOP maintenance experience) recommends the following practical guidelines—designed to avoid common mistakes and reduce downtime:

• Inspection Schedule: Conduct visual and pressure tests every 28 days during routine operations. Check for signs of leakage, corrosion, or wear (e.g., O-ring swelling, piston scratches, thread galling). Perform a comprehensive disassembly inspection every 5 months or 450 BOP cycles (whichever comes first) to replace worn components before they fail. Pay special attention to lip seal rings and wear rings, as these are the most common failure points.

• Seal Maintenance: Replace O-rings, Y rings, and backup rings if you notice swelling, cracking, extrusion, or abrasion. Always use the provided OEM seals—generic seals may not match the dimensional tolerance or material requirements, leading to leakage and system failure. Store seals in airtight packaging to prevent UV degradation and dust contamination, and avoid storing them near ozone sources (e.g., electrical equipment).

• Component Care: Clean hydraulic cylinders, pistons, and connecting plates with non-abrasive solvents (e.g., mineral spirits) to remove mud residue—abrasive cleaners can scratch surfaces and damage seals. Lubricate threaded connectors and wear rings with high-temperature lithium-based grease before installation to reduce friction and prevent thread galling. For piston rods, apply a thin layer of anti-corrosion oil after cleaning to prevent rust.

• Storage Guidelines: Store all parts in a dry, climate-controlled warehouse (temperature: 10–30°C, humidity < 60%). Metallic components should be stored on rust-resistant racks, and elastomeric seals should be kept away from direct sunlight. Hydraulic cylinders should be stored in a horizontal position to prevent internal rust and seal damage.

• Replacement Criteria: Replace large hydraulic cylinders if internal leakage exceeds 0.45 L/min at rated pressure. Replace main pistons if wear exceeds 0.15 mm on the piston surface. Replace seal rings if they show signs of compression set (more than 0.3 mm). Using damaged parts can lead to BOP failure and well control incidents—always follow these replacement guidelines to ensure safety.

We supply the following spare parts:

3. Frequently Asked Questions (FAQs)

4. Real-World Field Failure & Repair Cases

Case 1: Onshore Drilling Rig, Permian Basin, Texas, USA

Equipment: FZ28-35 Ram BOP (2C03.12 Large hydraulic cylinder, 100.97×5.33 O-ring, C664-22 Backup ring)
Fault: Slow ram closure (18 seconds vs. standard 6 seconds) and hydraulic leakage at the cylinder cap; diagnosed as O-ring extrusion and cylinder internal wear due to high mud contamination (12,000 mg/L particulate).
Load & Data: Operating pressure: 10,000 PSI; temperature: 98°C; mud type: oil-based mud (OBM); daily BOP cycles: 28.
Repair & Outcome: Replaced the 2C03.12 Large hydraulic cylinder, 100.97×5.33 O-ring, and C664-22 Backup ring; cleaned the hydraulic system and replaced the filter. Restoration time: 4.5 hours. Post-repair: Ram closure time reduced to 5.8 seconds; no leakage detected during a 24-hour pressure test. Client Feedback: “These parts restored full BOP functionality and eliminated unplanned downtime—we’ve saved $18,000 in maintenance costs over 6 months, and the cylinder has performed flawlessly.”

Case 2: Offshore Platform, North Sea

Equipment: FZ35-35 Ram BOP (2C03.11A Main Piston, 2C02.08 Lip Seal Rings of Main Piston)
Fault: Piston leakage and reduced ram force; diagnosed as lip seal ring wear and piston surface scratches due to sour service (H₂S partial pressure: 0.0005 MPa) and saltwater corrosion.
Load & Data: Operating pressure: 8,000 PSI; temperature: 125°C; environment: sour service, 80 m water depth; BOP age: 4 years.
Repair & Outcome: Replaced the 2C03.11A Main Piston and 2C02.08 Lip Seal Rings; polished the cylinder inner surface to remove scratches. Restoration time: 5.5 hours. Post-repair: Piston leakage eliminated; ram force restored to 9,500 lbs (rated force: 9,400 lbs); no wear detected after 150 cycles. Client Feedback: “The NACE-compliant parts held up perfectly in sour service—we haven’t had a piston failure in 8 months, and the repair was faster than expected.”

Case 3: Workover Rig, Abu Dhabi, Middle East

Equipment: FZ23-21 Ram BOP (2C01.13 Bolt 1/2-8UNx6 1/4, 2C03.06 Locking Axle Seat)
Fault: Bolt loosening and locking axle seat failure; diagnosed as thread galling and axle seat wear due to high temperature (155°C) and frequent assembly/disassembly (18 times/month).
Load & Data: Operating pressure: 7,000 PSI; temperature: 155°C; assembly frequency: 18 times/month; mud type: water-based mud (WBM).
Repair & Outcome: Replaced the 2C01.13 Bolts with anti-galling coated versions and 2C03.06 Locking Axle Seat; applied high-temperature thread locker to all connections. Restoration time: 3.5 hours. Post-repair: No bolt loosening detected during 72-hour operation; assembly/disassembly time reduced by 35%. Client Feedback: “The anti-galling bolts and durable axle seat have cut our maintenance time by 2.5 hours per BOP—we no longer worry about unexpected failures during workover operations.”

Case 4: Arctic Drilling Rig, Siberia, Russia

Equipment: FZ18-35 Ram BOP (2C02.12 Large hydraulic cylinder, 300X5.3 O-ring, 2C01.48 Wear Rings of Main Piston)
Fault: Cylinder leakage and piston wear; diagnosed as O-ring hardening and wear ring abrasion due to low temperature (-38°C) and cold mud exposure.
Load & Data: Operating pressure: 6,500 PSI; temperature: -38°C; mud type: water-based mud (WBM); daily BOP cycles: 20.
Repair & Outcome: Replaced the 2C02.12 Large hydraulic cylinder, 300X5.3 O-ring (low-temperature NBR material), and 2C01.48 Wear Rings; preheated components to 12°C before installation (per our engineer’s recommendation). Restoration time: 5 hours. Post-repair: Cylinder leakage eliminated; piston wear reduced to 0.05 mm per 100 cycles; BOP operates reliably at -38°C. Client Feedback: “These parts perform flawlessly in arctic conditions—we don’t have to shut down operations due to component failure, even in extreme cold.”

5. Procurement Guidance & Technical Reference

This spare parts suite is designed to simplify procurement and maintenance for FZ Series Ram BOP operators, providing a unified, reliable source for all critical components. We offer clear procurement and technical reference standards to help you make informed decisions and resolve technical issues quickly—ensuring you get the right parts to keep your BOPs running safely and efficiently.

• Procurement Standards: All parts are categorized by BOP model and component type, with clear part numbers (e.g., 2C03.12, 2C02.01().00, SKZF101.01H) for easy ordering. We offer pre-packaged maintenance kits (e.g., seal kits, piston kits, fastener kits) for routine overhauls, reducing procurement time and costs by 25%. For emergency repairs, we provide a 24/7 technical support line to help you identify the correct part and ensure quick replacement.

• Technical Reference: Our installation manual includes step-by-step instructions, torque specifications (e.g., 2C01.13 Bolt: 175 N·m), and troubleshooting guides for common issues (e.g., leakage, slow actuation). Our engineering team is available to provide custom technical advice for unique operating conditions (HPHT, sour service, arctic environments), helping you avoid common pitfalls and extend BOP service life.

All parts are backed by a quality guarantee—we stand behind the performance and durability of every component, with a 12-month warranty against manufacturing defects. Whether you need routine maintenance parts, emergency replacements, or custom-modified components, we are committed to providing the parts you need to keep your FZ Series Ram BOPs running reliably. Contact our sales team to discuss your specific BOP model, operating conditions, and maintenance requirements—we will provide a customized parts list and quotation tailored to your needs, ensuring you get the right parts at the right price.

contact us ：

Emeil: [email protected]  

whatsapp: +86 15275658619