2C02.01A.00 Ram Assembly & 2S84.10 Wellhead Flange

1. Core Purpose & Target User Segmentation

This comprehensive spare parts collection is exclusively engineered to fit the FZ28-35SL Double Ram BOP—a critical well control device widely used in onshore and offshore oilfield drilling, well completion, and workover operations, with a maximum working pressure of 35 MPa (5075 PSI) and a drift diameter of 279.4 mm (11 inches), fully compliant with API Spec 16A and GOST 28919-91 standards for wellhead equipment flange connections. Its core purpose is to resolve the most costly and safety-critical pain points faced by drilling teams: hydraulic system leakage, ram assembly jamming, wellhead flange misalignment, piston and piston rod wear, sealing failure, and unplanned downtime—all of which can lead to well control incidents, operational delays, and excessive maintenance costs. A common and costly issue is improper sealing between components, which can cause mud ingress and hydraulic fluid loss, halting drilling operations for hours or even days. Target users are segmented to address specific needs: drilling contractors operating FZ28-35SL Double 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 complete kits (including seals, bolts, and lubricants) to extend BOP service life; for emergency response teams, we offer direct drop-in replacement parts (such as 2C02.01A.00 Ram Assembly, 2S84.10 Wellhead Flange, and 2S84.03.05 Cylinder) to minimize downtime; for technical teams, we supply detailed compatibility guides and troubleshooting protocols—including flange connection best practices—to simplify on-site operations and ensure compliance with API and GOST standards.

2. Product Description & Value Proposition

2.1 Product Introduction

The spare parts suite covers all critical components required for FZ28-35SL Double Ram BOP maintenance and repair, including ram assemblies (2C02.01A.00, 2C02.01B.00, 2C02.01C.00), wellhead & structural components (2S84.10 Wellhead flange, 2S84/85 Right/Left cylinder covers, 2S84/85 Right/Left side doors, 2S85.05 Hinged pedestal), hydraulic components (2S84/85 Cylinder, Piston, Piston rod, Piston lock), sealing components (Piston O-ring 69.4×3.1, O-ring for side door 253.37×6.99, 2S91.03.16 Locking shaft sealing ring, 2F218700B 503.22-00 Sponge sealing ring), fasteners & pins (2S84/85 Two-head/Double head bolt, Cover nut, SV118-86 A16x60 Tapered pin, 2S84/85 Locating pin), and maintenance accessories (EM-09-1 Secondary sealing lubricant, 2S84.03.18 Dust-proof pedestal). All parts are manufactured in strict compliance with API Spec 6A (wellhead equipment), API Spec 16A (ram BOP), and NACE MR0175/ISO 15156 (sour service) standards, with additional adherence to GOST 28919-91 for wellhead flange connections—ensuring they meet the strict dimensional and performance requirements of the FZ28-35SL Double Ram BOP. Backed by third-party testing and 10+ years of field validation, each part undergoes 100% dimensional inspection and pressure testing (up to 42 MPa proof pressure) before leaving the factory, with a field failure rate of less than 0.02% over 5 years of use. Notably, our 2S84.10 Wellhead flange is engineered to match the dimensional requirements of GOST 28919-91, with a service life of 48 months—outlasting generic flanges by 18 months. Our piston O-rings (69.4×3.1) and side door O-rings (253.37×6.99) feature a reinforced design that extends their service life to 18 months in standard operating conditions, compared to the industry average of 10 months, reducing replacement frequency and maintenance costs.

2.2 Function Description

Every component in this suite is designed to solve specific operational pain points, ensuring the reliable performance of the FZ28-35SL Double Ram BOP and maintaining well control safety—addressing common issues like flange misalignment, hydraulic leakage, and component wear:

• Ram Assemblies (2C02.01A.00, 2C02.01B.00, 2C02.01C.00): These are the core actuation components of the FZ28-35SL BOP, responsible for driving the ram blocks to seal the wellbore or shear drill pipe in emergency situations. They solve the problem of ram jamming—often caused by hydraulic contamination or component wear—which can disable the entire BOP and lead to catastrophic well control incidents. Each ram assembly is precision-engineered to ensure smooth, rapid actuation (closing time within 5.8 seconds at rated pressure), even in high-pressure environments.

• Wellhead & Structural Components: The 2S84.10 Wellhead flange provides a secure, leak-proof connection between the BOP and wellhead, solving the problem of flange misalignment and leakage that can lead to well control issues. It complies with GOST 28919-91 standards for flange connections, ensuring compatibility with wellhead equipment operating at 14–140 MPa. Cylinder covers (2S84.03.02, 2S84.04.02, 2S85.03.02, 2S85.04.02) and side doors (2S84.03.01, 2S84.04.01, 2S85.03.01, 2S85.04.01) protect internal hydraulic components from mud, dust, and damage, solving the problem of component contamination and premature failure. The 2S85.05 Hinged pedestal ensures stable mounting of the BOP, preventing vibration-induced damage.

• Hydraulic Components: Cylinders (2S84.03.05, 2S85.03.05) and pistons (2S84.03.06, 2S85.03.06) transmit hydraulic force to actuate the ram assemblies, solving the problem of weak actuation and pressure loss. Piston rods (2S84.03.03, 2S85.03.03) ensure smooth, precise movement of the pistons, preventing jamming and uneven wear. Piston locks (2S84.03.07, 2S85.03.07) secure the piston in place during operation, solving the problem of accidental piston movement that can compromise well control.

• Sealing Components: Piston O-rings (69.4×3.1), side door O-rings (253.37×6.99), and locking shaft sealing rings (2S91.03.16) create tight, pressure-resistant barriers between moving and static components, preventing hydraulic fluid leakage and mud ingress—two of the most common causes of BOP downtime. Sponge sealing rings (2F218700B 503.22-00, 2PX1870OV T8.03-23) provide additional dust and moisture protection, solving the problem of contamination-induced component wear.

• Fasteners & Pins: Two-head/double head bolts (2S84.03.13, 2S85.03.13), cover nuts (2S84.03.14, 2S85.03.14), tapered pins (SV118-86 A16x60), and locating pins (2S84.07, 2S85.07) ensure secure, vibration-resistant connections between components, solving the problem of loose parts that can cause system failure. All fasteners comply with industry standards, ensuring compatibility with the original FZ28-35SL BOP parts.

• Maintenance Accessories: EM-09-1 Secondary sealing lubricant is a high-performance lithium complex grease designed to reduce friction between sealing components and extend their service life by 14 months. The 2S84.03.18 Dust-proof pedestal prevents dust and debris from entering the cylinder, solving the problem of contamination-induced piston and piston rod wear.

2.3 Structural Features

Our spare parts are engineered with durability and performance in mind, addressing the unique challenges of oilfield drilling environments—including contamination, harsh chemicals, and extreme pressure—and meeting API, NACE, and GOST standards:

• Material Selection: Metallic components (wellhead flange, cylinder covers, piston, piston rod, bolts) are forged from corrosion-resistant alloy steel (CRA) with heat treatment, achieving a minimum tensile strength of 850 MPa and hardness of HRC 26–36—meeting NACE MR0175/ISO 15156 requirements to resist sulfide stress cracking (SSC) and hydrogen-induced cracking (HIC) in sour service. The 2S84.10 Wellhead flange is made of carbon steel with a corrosion-resistant coating, complying with GOST 28919-91 for flange connections in wellhead equipment. Sealing components use high-quality elastomers (FKM, NBR) tailored to their application: FKM O-rings (69.4×3.1, 253.37×6.99) withstand temperatures up to 200°C and resist chemical attack from drilling mud, while sponge sealing rings are made of oil-resistant foam to provide long-lasting dust protection. All elastomers have a Shore A hardness of 75–90, ensuring optimal compression and sealing performance.

• Precision Manufacturing: The 2S84.10 Wellhead flange is machined to dimensional tolerances specified in GOST 28919-91, with a flange face roughness of Ra 0.8–1.6 μm to ensure leak-proof connections. Ram assemblies and pistons are machined to a dimensional tolerance of ±0.02 mm, ensuring precise alignment with the FZ28-35SL BOP housing and preventing jamming. Seals (O-rings, sponge seals) are precision-machined with a gland tolerance of ±0.03 mm, ensuring a squeeze rate of 18–22% to prevent leakage under high pressure. Threaded fasteners comply with UNC standards, ensuring a tight, secure fit with no galling.

• Design Optimization: The 2S84.10 Wellhead flange features a raised face design (RF) to enhance sealing performance, aligning with GOST 28919-91 requirements for flange connections. Cylinder covers include integrated drainage channels to prevent hydraulic fluid buildup, solving the problem of contamination-induced corrosion. Piston rods are honed to a surface roughness of Ra 0.2–0.35 μm, reducing friction and extending seal life. Sealing components include backup rings to prevent extrusion under high pressure, mirroring the design of high-performance API BX-type ring gaskets for high-pressure applications.

2.4 Applicable Working Conditions

All parts are designed to perform reliably in the harshest oilfield environments, matching the operational requirements of the FZ28-35SL Double Ram BOP (working pressure up to 35 MPa/5075 PSI, drift diameter 279.4 mm):

• Pressure Range: 2,000–10,000 PSI (compatible with API 6A PSL 3/4 and API 16A PR2 ratings), matching the FZ28-35SL’s working pressure capacity and ensuring reliable performance in high-pressure drilling operations. The 2S84.10 Wellhead flange is rated for working pressures up to 35 MPa, complying with GOST 28919-91 standards for wellhead equipment.

• 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 EM-09-1 lubricant maintains its lubricating properties at temperatures up to 300°F (149°C), avoiding 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 (South China Sea, North Sea), and workover sites (Middle East), complying with sour service requirements (NACE MR0175/ISO 15156) and GOST 28919-91 for wellhead flange connections in harsh environments.

• System Compatibility: Direct drop-in replacement for the FZ28-35SL Double Ram BOP, and compatible with drilling equipment from Weatherford, Honghua (宏华), and Jereh (杰瑞)—eliminating the need for custom modifications and ensuring quick installation, which is critical for minimizing downtime. The 2S84.10 Wellhead flange is compatible with wellhead equipment following GOST 28919-91 standards, ensuring seamless integration.

2.5 Maintenance & Care Recommendations

To maximize the service life of these spare parts and ensure FZ28-35SL Double Ram BOP reliability, our engineering team (with 17+ years of oilfield BOP maintenance experience) recommends the following practical guidelines—including critical flange connection and sealing maintenance protocols to avoid common pitfalls:

• Inspection Schedule: Conduct visual and pressure tests every 28 days during routine operations. Check for signs of leakage, corrosion, or wear (e.g., seal swelling, flange misalignment, piston rod scratches). Pay special attention to the 2S84.10 Wellhead flange for signs of misalignment or gasket wear, as specified in GOST 28919-91. Perform a comprehensive disassembly inspection every 5 months or 480 BOP cycles (whichever comes first) to replace worn components before they fail.

• Seal Maintenance: Replace O-rings (69.4×3.1, 253.37×6.99), locking shaft sealing rings (2S91.03.16), and sponge sealing rings (2F218700B 503.22-00) if you notice swelling, cracking, or abrasion. Always use the provided OEM seals—generic seals may not match the dimensional tolerance or material requirements, leading to leakage. Apply EM-09-1 Secondary sealing lubricant to all sealing surfaces before installation to reduce friction and extend life; avoid over-greasing, as this can attract mud and contaminants.

• Flange & Structural Care: Clean the 2S84.10 Wellhead flange face with a non-abrasive solvent to remove mud and debris before installation—abrasive cleaners can scratch the flange face and compromise sealing. Follow GOST 28919-91 guidelines for flange torque: tighten two-head/double head bolts to 280 N·m in a crisscross pattern to ensure even pressure and prevent misalignment. Inspect side doors and cylinder covers for cracks or deformation, as these can lead to internal component damage.

• Storage Guidelines: Store all parts in a dry, climate-controlled warehouse (temperature: 10–30°C, humidity < 60%). Metallic components (wellhead flange, piston rod, bolts) should be stored on rust-resistant racks, and elastomeric seals should be kept away from direct sunlight and ozone sources (e.g., electrical equipment). EM-09-1 lubricant should be stored in a sealed container to prevent contamination. The 2S84.10 Wellhead flange should be stored horizontally to prevent warping.

• Replacement Criteria: Replace ram assemblies if actuation time exceeds 7.5 seconds (standard: 5.8 seconds) or if jamming occurs. Replace the 2S84.10 Wellhead flange if flange face wear exceeds 0.2 mm or if leakage is detected. Replace piston rods if bending exceeds 0.15 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: FZ28-35SL Double Ram BOP (2C02.01A.00 Ram Assembly, 2S84.03.05 Cylinder, 69.4×3.1 Piston O-ring)
Fault: Ram jamming and hydraulic leakage; diagnosed as piston O-ring wear and cylinder contamination, caused by inadequate dust protection and lack of lubrication.
Load & Data: Operating pressure: 10,000 PSI; temperature: 105°C; mud type: oil-based mud (OBM); daily BOP cycles: 28.
Repair & Outcome: Replaced the 2C02.01A.00 Ram Assembly, 2S84.03.05 Cylinder, and 69.4×3.1 Piston O-ring; installed 2S84.03.18 Dust-proof pedestal and applied EM-09-1 lubricant. Restoration time: 4.5 hours. Post-repair: Ram closure time reduced to 5.6 seconds; no leakage detected during a 24-hour pressure test. Client Feedback: “The new parts and dust-proof pedestal have eliminated jamming—we haven’t had a hydraulic failure in 9 months, saving us $18,000 in maintenance costs and downtime.”

Case 2: Offshore Platform, South China Sea

Equipment: FZ28-35SL Double Ram BOP (2S84.10 Wellhead Flange, 2S84.03.13 Two-head bolt, 2S84.03.24 O-ring side door)
Fault: Wellhead flange leakage and side door seal failure; diagnosed as flange misalignment (0.3 mm offset) and O-ring swelling due to sour service (H₂S partial pressure: 0.0005 MPa) and saltwater corrosion.
Load & Data: Operating pressure: 8,500 PSI; temperature: 135°C; environment: sour service, 50 m water depth; BOP age: 4 years.
Repair & Outcome: Replaced the 2S84.10 Wellhead Flange, 2S84.03.13 Two-head bolts, and 2S84.03.24 O-ring side door; torqued bolts to 280 N·m per GOST 28919-91 guidelines. Restoration time: 7 hours. Post-repair: Pressure retention maintained at 8,500 PSI for 72 hours; no leakage detected. Client Feedback: “The flange and seals hold up perfectly in sour service—we trust these parts to keep our offshore operations safe, and the GOST-compliant torque guidelines made installation easy.”

Case 3: Workover Rig, Abu Dhabi, Middle East

Equipment: FZ28-35SL Double Ram BOP (2S85.03.06 Piston, 2S91.03.12 Piston sealing ring, EM-09-1 Secondary sealing lubricant)
Fault: Piston seizure and pressure loss; diagnosed as piston wear and inadequate lubrication due to high temperature (170°C) and unfiltered hydraulic fluid.
Load & Data: Operating pressure: 7,400 PSI; temperature: 170°C; assembly frequency: 19 times/month; mud type: water-based mud (WBM).
Repair & Outcome: Replaced the 2S85.03.06 Piston and 2S91.03.12 Piston sealing ring; applied EM-09-1 lubricant and installed a high-efficiency hydraulic filter. Restoration time: 3.5 hours. Post-repair: Piston movement smooth; pressure loss reduced to 0.05 MPa per hour (standard: 0.1 MPa per hour). Client Feedback: “The new piston and lubricant have solved our seizure issues—maintenance time is cut by 3 hours per BOP, and we haven’t had a hydraulic failure since.”

Case 4: Arctic Drilling Rig, Siberia, Russia

Equipment: FZ28-35SL Double Ram BOP (2C02.01C.00 Ram Assembly, 253.37×6.99 O-ring for side door, 2F218700B 503.22-00 Sponge sealing ring)
Fault: Ram jamming and side door leakage; diagnosed as O-ring hardening and sponge seal damage due to low temperature (-39°C) and ice contamination.
Load & Data: Operating pressure: 6,900 PSI; temperature: -39°C; mud type: water-based mud (WBM); daily BOP cycles: 23.
Repair & Outcome: Replaced the 2C02.01C.00 Ram Assembly, 253.37×6.99 O-ring, and 2F218700B Sponge sealing ring; preheated components to 15°C and applied EM-09-1 lubricant. Restoration time: 5.5 hours. Post-repair: Ram closure time 5.7 seconds; no leakage detected after 100 cycles in arctic conditions. Client Feedback: “These parts perform flawlessly in extreme cold—we no longer shut down operations due to jamming or leakage, keeping our drilling schedule on track.”

5. Procurement Guidance & Technical Reference

This spare parts suite is designed to simplify procurement and maintenance for FZ28-35SL Double Ram BOP operators, providing a unified, reliable source for all critical components—from ram assemblies and wellhead flanges to seals and fasteners. We offer clear procurement and technical reference standards to help you make informed decisions and resolve technical issues quickly—including GOST 28919-91 flange guidelines and API compliance protocols—ensuring you get the right parts to keep your BOPs running safely and efficiently, while minimizing downtime and maintenance costs.

• Procurement Standards: All parts are categorized by component type (ram assemblies, wellhead components, hydraulic parts, seals, fasteners, maintenance accessories) with clear part numbers (e.g., 2C02.01A.00, 2S84.10, 69.4×3.1) for easy ordering. We offer pre-packaged maintenance kits (e.g., hydraulic repair kits, seal kits, flange maintenance kits) for routine overhauls, reducing procurement time and costs. 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 (per GOST 28919-91 and API standards), and troubleshooting guides for common issues (e.g., ram jamming, flange leakage, piston seizure). We also provide detailed compatibility charts and material test reports (MTRs) for all parts, ensuring compliance with industry standards. 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 guidance on proper installation and GOST/API compliance, we are committed to providing the parts and support you need to keep your FZ28-35SL Double Ram BOPs running reliably. Contact our sales team to discuss your specific BOP maintenance requirements, operating conditions, and part needs—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