Shanghai Shenkai FZ5435S/2FZ5435S Ram Blowout Preventer (BOP)

Introduction

This guide is exclusively tailored for Shanghai Shenkai’s FZ5435S (Single Ram BOP) and 2FZ5435S (Double Ram BOP), high-performance well control devices engineered for medium to high-pressure oil and gas drilling operations. It caters to the specialized needs of drilling contractors, on-site maintenance technicians, and procurement specialists in the oilfield industry, focusing on the models’ multi-type ram assemblies (pipe ram, shear ram, variable diameter ram) and dedicated part ecosystem—including 2S90 series pipe rams, SBR series shear rams, VBR series variable diameter rams, and SKZF/C663-22 sealing components. Its core purpose is to serve as a dual-functional reference: providing precise part compatibility, procurement benchmarks, and one-year spare parts inventory optimization strategies, while delivering actionable technical solutions for on-site fault diagnosis, repairs, and routine maintenance. Compliant with API Spec 16A (Wellhead and Christmas Tree Equipment) and Chinese national standards (GB/T 77, GB/T 297), this guide ensures FZ5435S/2FZ5435S operations adhere to strict industry safety protocols, minimize unplanned downtime, and maximize operational efficiency. Whether for daily upkeep, emergency shear operations, or bulk parts sourcing, the content integrates field-validated experience and authoritative technical insights to safeguard wellbore integrity and personnel safety in complex drilling scenarios.

Product Overview

The Shanghai Shenkai FZ5435S series BOPs (single and double ram configurations) are designed to deliver reliable well control with versatile ram options, adapting to diverse drilling and emergency needs. The single ram model (FZ5435S) features one set of ram assemblies, while the double ram variant (2FZ5435S) is equipped with two sets, offering enhanced safety redundancy for high-risk operations. A key advantage of this series is its compatibility with three core ram types: 2S90 series pipe rams (covering blind, 5″, 5 1/2″, 7″, 10 3/4″, 13 3/8″ sizes), SBR5435SA series shear rams (for emergency drill pipe shearing), and VBR5435SA series variable diameter rams (adapting to 4 1/2″–5 1/2″ pipe sizes). Core components include side door seal structures (615×7/600×7 O-rings, 2FZ5321B rubber blankets), ram shaft seal assemblies (SKZF135.01 Y-rings, SFZ1310 retainers), secondary seal systems (SFZ2835 cocks/check valves, EM-09-1 grease), and locking shaft seal assemblies (2FZ1870DBYS lip rings, SFZ1310 wiper rings). All parts follow a standardized numbering system, with high commonality between single and double ram models (differing primarily in part quantity) to simplify inventory management and reduce procurement costs. The models share consistent structural design, including 2S105 series hydraulic cylinders, 2S90 series hinge structures, and TPM 360 piston seals, ensuring stable hydraulic actuation and pressure resistance.

Functional Description

The FZ5435S series BOPs deliver comprehensive well control through coordinated operation of specialized ram assemblies and sealing systems, tailored to medium-high pressure drilling requirements:

Multi-Type Ram Control: Pipe rams (2S90.01 series) provide targeted sealing for diverse pipe sizes—blind rams (2S90.01A.00) enable full wellbore closure during maintenance, while size-specific pipe rams seal around drill pipes to maintain pressure during drilling. Shear rams (SBR5435SA series) offer emergency drill pipe shearing capability, with upper/lower shear ram bodies and dedicated front/top seals ensuring clean shearing and post-shear sealing. Variable diameter rams (VBR5435SA series) adapt to 4 1/2″–5 1/2″ pipes, reducing the need for multiple ram replacements and improving operational flexibility.

Layered Sealing Protection: The sealing system integrates multiple defensive layers: side door seal structures (615×7/600×7 O-rings, rubber blankets) prevent fluid leakage at door connections; ram shaft seal assemblies (SKZF135.01 Y-rings, SKZF135.02 backup rings) safeguard hydraulic fluid integrity; locking shaft seal assemblies (2FZ1870DBYS lip rings, SFZ1310 wiper rings) prevent contamination and leakage; and the secondary seal system allows on-site injection of EM-09-1 grease via SFZ2835 cocks/check valves for emergency leak remediation without disassembly. C663-22 backup rings enhance seal stability and prevent extrusion under high pressure.

Hydraulic Actuation & Locking: 2S105.03.03 hydraulic cylinders drive piston (2S102.03.06) and ram shaft (2S105.03.04) movement, with TPM 360 seals ensuring efficient hydraulic power transmission. Locking screws (2S90.03.04) and stop blocks (C17.08.03) secure ram positions after actuation, preventing accidental displacement under pressure. Guide pins (2FZ5321B.02-01) ensure precise ram alignment during actuation, reducing friction and extending component service life.

Stable Hinge & Structural Support: 2S90.05 hinge blocks, GB/T 297 bearings (2007914), and GB/T118 locating pins provide robust support for side doors, enabling smooth opening/closing and precise ram alignment. O-rings (115×5.7, 59.69×5.33) seal hinge connections, preventing fluid intrusion and structural corrosion.

Structural Features

The FZ5435S series BOPs feature a robust, maintenance-friendly design optimized for reliability, versatility, and on-site serviceability:

Versatile Ram Compatibility: The series supports three ram types (pipe, shear, variable diameter), covering blind closure, size-specific pipe sealing, emergency shearing, and multi-size pipe adaptation. This versatility eliminates the need for separate BOP units for different operations, reducing equipment investment and on-site footprint.

Standardized Part Ecosystem: Core components follow a consistent naming convention—2S90 for pipe rams/hinges, SBR for shear rams, VBR for variable diameter rams, SKZF for seals, and C663-22 for backup rings. High part commonality between single and double ram models (e.g., seals, hinge parts, hydraulic components) reduces inventory complexity, while dedicated ram parts ensure precise compatibility.

Modular & Accessible Design: Sealing assemblies (ram shaft, locking shaft) and ram units adopt modular design, allowing technicians to replace worn parts without full disassembly. Hinge-structured side doors enable quick access to ram assemblies, significantly reducing maintenance time. Standardized fasteners (GB/T77, GB5782) allow the use of common tools for on-site repairs.

Pressure & Corrosion Resistance: Structural parts (body, hydraulic cylinders, hinge blocks) are made of high-strength materials to withstand medium-high pressure operations. Sealing components and rubber parts (rubber blankets, O-rings) resist corrosion from water-based/oil-based/synthetic-based drilling fluids, ensuring long-term durability in harsh field conditions.

Applicable Operating Conditions

The FZ5435S (Single Ram BOP) and 2FZ5435S (Double Ram BOP) are optimized for medium-high pressure onshore and shallow offshore drilling scenarios, with specific applicability to the following conditions:

Pressure & Fluid Compatibility: Designed for medium-high pressure drilling operations, with sealing systems rated to withstand corresponding working pressures. Compatible with water-based mud (WBM), oil-based mud (OBM), and synthetic-based mud (SBM), ensuring stable performance in diverse fluid environments.

Pipe Size Adaptability: With pipe rams covering 5″–13 3/8″, variable diameter rams for 4 1/2″–5 1/2″, and shear rams for emergency operations, the series is highly versatile for wells with complex casing programs and diverse drill pipe dimensions, widely used in onshore oilfields and shallow offshore platforms.

Well Types & Operations: Ideal for onshore drilling, workover operations, and shallow offshore drilling projects, particularly in regions with moderate to high formation pressure fluctuations. The double ram model (2FZ5435S) provides enhanced safety redundancy for high-risk wells, while the single ram model (FZ5435S) offers cost-effective performance for standard drilling scenarios. Shear rams make it suitable for wells requiring emergency drill pipe shearing capability.

Environmental Resilience: Suitable for ambient temperatures common in most onshore and shallow offshore regions, with components designed to resist moisture, dust, and drilling fluid corrosion. Wiper rings and dust seals prevent solid particle contamination, ensuring consistent performance in harsh field conditions.

Maintenance & Care Recommendations

Proactive maintenance is critical to extending the service life and ensuring the reliability of FZ5435S series BOPs. Below are model-specific best practices aligned with API Spec 16A and relevant standards:

Regular Inspection Schedules: Conduct weekly visual checks of sealing components, hydraulic connections, hinge structures, and locking shafts for leaks, corrosion, or wear. Perform quarterly disassembly inspections of ram assemblies, sealing groups, and secondary seal systems—replace worn parts per the one-year recommended spare parts list. Verify the integrity of O-rings, backup rings, and rubber blankets during each inspection to prevent extrusion under pressure.

Seal Maintenance: Replace SKZF135.01 Y-rings, 2FZ1870DBYS lip rings, and SFZ1310 wiper rings every 6 months or if cracks/deformation are detected. Inject EM-09-1 secondary seal grease every 3 months to maintain leak resistance and lubricate sealing surfaces. Clean sealing grooves thoroughly before installing new seals to remove residue and ensure proper seating. Replace rubber blankets (2FZ5321B.02.02-02) if signs of aging or wear appear.

Ram & Actuation System Care: Clean ram bodies, front seals, and top seals after each use to remove drilling fluid residue, avoiding damage to rubber surfaces. Inspect shear ram cutting edges for wear and replace upper/lower shear ram bodies (SBR5435SA-01/-02) if dull. Lubricate piston rods, locking shafts, hinge bearings, and guide pins monthly with anti-corrosion lubricant to reduce friction and prevent seizing.

Fastener & Structural Maintenance: Torque door bolts (2S90.06), hydraulic cylinder bolts (2S105.03.02), and hinge screws (GB70.1 M24×155) to manufacturer specifications during each inspection. Check stop blocks (C17.08.03) for tightness and replace worn or deformed fasteners immediately to maintain structural integrity. Inspect hinge bearings (GB/T 297 2007914) for smooth rotation and replace if noisy or seized.

Auxiliary Component Care: Clean SFZ2835 cocks, SFZ1310.32-00 check valves, and oil cups (GB/T1152 M10×1) quarterly to prevent clogging. Flush secondary seal grease injection lines during each maintenance cycle to ensure emergency usability. Verify the functionality of variable diameter ram screws (GB/T70.1 M12×135) and tighten if loose.

Parts of pipe ram

Parts list of shear ram assembly

Parts list of variable diameter ram assembly

Part list of Side Door Seal Structure

Part list of Ram Shaft Seal Assembly

Parts list of Secondary Seal System

Parts list of Locking Shaft Seal Assembly

Parts list of Hinge structure

Spare Parts list for one year

Field Fault Repair Cases

The following real-world cases provide practical troubleshooting tips for common FZ5435S series faults, helping technicians resolve issues quickly and minimize downtime:

Case 1: Ram Shaft Hydraulic Leakage

Symptom: Hydraulic fluid leakage around the ram shaft. Root Cause: SKZF135.01 Y-rings were degraded by high-temperature hydraulic fluid, and 150×3.55/136×3.55 O-rings were deformed, compromising sealing integrity. Repair: Replaced the entire ram shaft seal set (Y-rings, O-rings, backup rings, retainers), cleaned the ram shaft surface to remove burrs, and inspected the bushing (2FZ35105A.03-13) for damage. Post-repair hydraulic pressure testing confirmed no leakage. Preventive Measure: Replace the seal set every 6 months and monitor hydraulic fluid temperature to avoid exceeding operational limits.

Case 2: Shear Ram Sealing Failure Post-Shearing

Symptom: Fluid leakage after using shear rams to cut drill pipe. Root Cause: SBR5435SA-04.00 front seals and SBR5435SA-03.00/05.00 top seals were damaged during shearing, and the shear ram cutting edges were dull, causing incomplete sealing.Repair: Replaced all shear ram seals, inspected upper/lower shear ram bodies for dull edges (replaced if necessary), and realigned the shear ram assembly. A follow-up pressure test confirmed effective sealing.Preventive Measure: Inspect shear ram seals and cutting edges after each use, and replace seals every 3 shear operations or 6 months, whichever comes first.

Case 3: Side Door Leakage

Symptom: Fluid leakage at the side door connection. Root Cause: 615×7/600×7 O-rings were worn and 2FZ5321B.02.02-02 rubber blankets were aged, losing sealing elasticity. Repair: Replaced worn O-rings and aged rubber blankets, cleaned the side door sealing surface to remove residue, and torqued door bolts (2S90.06) to manufacturer specifications. Leakage was eliminated post-repair. Preventive Measure: Replace side door O-rings and rubber blankets every 6 months, and check bolt torque during weekly inspections.

Case 4: Secondary Seal Grease Injection Failure

Symptom: Inability to inject EM-09-1 grease into the secondary seal system. Root Cause: SFZ1310.32-00 check valves were clogged with dried grease and debris, blocking grease flow, and SFZ2835-37 cocks were stuck. Repair: Disassembled the check valves and cocks, cleaned them thoroughly with a solvent, flushed the injection line, and reinstalled components. Grease flow was restored immediately. Preventive Measure: Clean secondary seal components quarterly, flush the grease line during each maintenance cycle, and store EM-09-1 grease in a sealed container to avoid contamination.

FAQ (Frequently Asked Questions)

Procurement Guidance

The safety and reliability of Shanghai Shenkai FZ5435S/2FZ5435S BOPs depend entirely on genuine, model-compatible parts. We supply a full range of authentic components tailored to these models, including 2S90 series pipe rams (all sizes), SBR5435SA shear rams, VBR5435SA variable diameter rams, ram shaft/locking shaft sealing groups, side door seal components, secondary seal system parts, and all items in the one-year spare parts list. All parts are manufactured to API Spec 16A, GB standards, and Shanghai Shenkai’s original equipment specifications, with traceable material certificates and batch records to ensure perfect fit, pressure resistance, and consistent performance.

For procurement, prioritize high-wear components from the one-year spare parts list, including SKZF135.01 Y-rings, 2FZ1870DBYS lip rings, SFZ1310 wiper rings, C663-22 backup rings, and 2FZ5321B rubber blankets. Double quantities for 2FZ5435S (double ram) models, and stock size-specific front seals for commonly used pipe diameters. Our oilfield technical experts provide free support to verify part compatibility, avoid mismatches, and optimize inventory based on your drilling scope and operational frequency. Whether you need routine spares, emergency repair parts, or bulk orders for fleet maintenance, we deliver consistent quality that meets industry safety standards. Contact us today to discuss your specific Shanghai Shenkai FZ5435S series requirements and secure reliable parts for your well control operations.

Conclusion

The Shanghai Shenkai FZ5435S (Single Ram BOP) and 2FZ5435S (Double Ram BOP) are versatile, high-reliability well control devices engineered to excel in medium-high pressure onshore and shallow offshore drilling operations. Their compatibility with pipe, shear, and variable diameter rams, layered sealing protection, modular design, and high part commonality make them adaptable to diverse operational scenarios—from standard drilling to emergency shear interventions. The models’ maintenance-friendly structure and compliance with global industry standards ensure safe, consistent performance while minimizing downtime and procurement costs.

This guide integrates authoritative technical insights, field-proven repair cases, and procurement best practices to support technicians and procurement professionals in maintaining operational continuity. By following model-specific maintenance schedules, using genuine Shanghai Shenkai parts, and leveraging the FAQs and troubleshooting tips, you can maximize the FZ5435S series’ service life and mitigate operational risks. Partnering with a trusted supplier for authentic components ensures compliance with safety protocols, safeguarding personnel, assets, and wellbore integrity. Invest in quality parts and proactive maintenance to keep your Shanghai Shenkai FZ5435S BOPs operating at peak performance.

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