Core Application & Target User Requirements
This catalog is exclusively tailored for SHENKAI NL Series Annular Blowout Preventers (BOPs), including models FH1821NL, FH1835NL, FH1835/70NL, FH2321NL, and FH2821NL. Annular BOPs serve as critical primary well control devices in oil and gas drilling operations, responsible for sealing the annular space between drill strings (or casings) and wellbores, as well as closing empty wellbores during emergency situations. The parts detailed herein are engineered to meet SHENKAI’s original equipment manufacturing (OEM) specifications, ensuring compatibility, high-pressure resistance, and reliable sealing performance in compliance with API 16A standards.
Target users include offshore/onshore drilling operation managers, BOP maintenance engineers, oilfield procurement specialists, and well control equipment service providers. Key user requirements addressed: 1) Precise part matching for specific NL series models to avoid compatibility issues; 2) Access to detailed material specifications and wear prevention guidance to extend part service life and reduce unplanned downtime; 3) Clear technical references for troubleshooting common annular BOP failures; 4) Reliable procurement criteria to ensure parts meet safety and performance standards. Proper selection and maintenance of these components are essential to safeguarding drilling personnel, equipment, and the environment, while maintaining operational efficiency and regulatory compliance.
Parts Classification & Technical Specifications
The SHENKAI NL series annular BOP parts are classified into four functional categories based on their operational roles: Pressure-Containing Structural Components, Primary Sealing Components, Wear-Resistant Components, and Fastening & Auxiliary Components. Each category includes detailed part information, technical parameters, and maintenance guidelines to support both procurement decision-making and on-site maintenance operations.
1. Pressure-Containing Structural Components
Pressure-containing structural components form the core load-bearing framework of the annular BOP, withstanding extreme downhole pressures (up to 70MPa for FH1835/70NL) and ensuring the integrity of the well control pressure boundary. These components are subjected to cyclic high-pressure loading, internal corrosion from drilling fluids (including H₂S and CO₂), and potential impact during transportation and installation. Failure of these parts can lead to catastrophic well control incidents, such as BOP housing rupture or uncontrolled wellbore pressure release.
Value Proposition: Manufactured from high-strength alloy steels with precision heat treatment, these components meet strict API 16A pressure vessel standards. Their robust design ensures long-term structural integrity under harsh drilling conditions, minimizing the risk of pressure-related failures. OEM compatibility guarantees seamless assembly and optimal performance with SHENKAI NL series BOPs.
No. | Description | FH1821NL Part No. | FH1835NL Part No. | FH1835/70NL Part No. | FH2321NL Part No. | FH2821NL Part No. | Material Specification | Primary Wear Causes | Maintenance & Handling Precautions |
1 | Bonnet | FH1821NL-01 | FH1835NL-01 | FH1835NL-01 | FH2321NL-01 | FH2821NL-02 | AISI 4140 alloy steel forging, normalized and tempered; surface nitriding treatment (hardness ≥ HRC 55) | Cyclic high-pressure fatigue; internal corrosion from acidic drilling fluids; thread wear at stud connection points; impact damage during handling | Conduct non-destructive testing (NDT) using magnetic particle inspection (MPI) for cracks annually; inspect thread connections for wear or deformation before assembly; torque studs to SHENKAI OEM specifications (refer to model-specific service manual); store in a dry, covered environment to prevent atmospheric corrosion; use lifting equipment with padded slings to avoid surface scratches |
2 | Shell | FH1821NL-02 | FH1835NL-13 | H08.01 | FH2321NL-14 | FH2821NL-01 | AISI 4340 alloy steel forging, quenched and tempered; internal surface hard chrome plating (thickness 0.015-0.025mm) for corrosion resistance | Internal erosion-corrosion from high-velocity drilling fluid flow; cyclic pressure fatigue at weld joints; external corrosion from harsh environmental conditions (e.g., saltwater for offshore applications) | Inspect internal surface for plating peeling, pitting, or scratches regularly; monitor weld joints for signs of fatigue using ultrasonic testing (UT) every 12 months of operation; apply anti-corrosion coating to external surfaces for offshore installations; avoid contact with sharp objects during storage and transportation; ensure proper alignment during installation to prevent uneven stress distribution |
3 | Piston | FH1835NL-14 | FH1835NL-14 | FH1835NL-14 | FH2321NL-07 | FH2821NL-16 | Hard-anodized 6061-T6 aluminum alloy (for low-pressure models) / AISI 4140 steel (for high-pressure models FH1835/70NL); precision-machined seal grooves | Seal groove wear from dynamic sealing movement; surface scoring from contaminated hydraulic fluid; corrosion from water ingress in hydraulic systems; bending stress from misalignment | Maintain hydraulic fluid cleanliness to ISO 4406 Class 16/13/10; inspect seal grooves for burrs or wear before seal replacement; check piston surface for anodization damage (aluminum models) or corrosion (steel models); ensure piston rod alignment within 0.05mm/m to prevent bending; lubricate seal grooves with compatible hydraulic fluid before installing new seals |
2. Primary Sealing Components
Primary sealing components are responsible for achieving and maintaining the annular seal between the BOP and drill string/wellbore, which is critical for well control. These elastomeric and composite components operate in harsh conditions, including high pressure, high temperature, and exposure to aggressive drilling fluids, chemicals, and wellbore debris. Premature seal failure, such as swelling, extrusion, or tearing, can result in seal leakage, loss of well control, and costly operational downtime.
Value Proposition: SHENKAI’s primary sealing components are manufactured from high-performance elastomers (NBR, FKM, polyurethane) tailored to the specific operating conditions of NL series BOPs. Their precision-molded design ensures consistent sealing performance, while resistance to chemical degradation and thermal aging extends service life. OEM specifications guarantee compatibility with seal grooves, preventing extrusion and ensuring reliable pressure retention.
No. | Description | FH1821NL Part No. | FH1835NL Part No. | FH1835/70NL Part No. | FH2321NL Part No. | FH2821NL Part No. | Material Specification | Primary Wear Causes | Maintenance & Handling Precautions |
1 | Packer | FH1835NL.02-00A | FH1835NL.02-00A | FH1835NL.02-00A | FH2321NL-02 | FH2821NL-05-00 | High-performance polyurethane (HPU) for FH1821NL/FH1835NL/FH1835/70NL; FKM-reinforced polyurethane for FH2321NL/FH2821NL (high-temperature resistance up to 150°C) | Abrasive wear from wellbore debris; chemical degradation from drilling fluid additives (e.g., surfactants, corrosion inhibitors); thermal aging; extrusion into gaps under high pressure; permanent set from prolonged compression | Store in a cool (15-25°C), dark, and dry environment away from direct sunlight and ozone sources; inspect for permanent set, cracks, or swelling before installation (replace if deformation exceeds 5%); clean wellbore debris thoroughly before BOP activation; avoid contact with incompatible chemicals (e.g., strong oxidizers, aromatic solvents); replace packers after 50 emergency closure cycles or 12 months of continuous use, whichever comes first |
2 | Seal-Adapeter Ring I.D. Upper | FH1835NL-06 | FH1835NL-06 | FH1835NL-06 | FH2321NL-10 | FH2821NL-09 | Nitrile rubber (NBR) Shore A 85-90 with fabric reinforcement for FH18 series; fluoroelastomer (FKM) for FH2321NL/FH2821NL (chemical resistance) | Shear stress from relative movement between components; extrusion under high pressure; corrosion from acidic drilling fluids; edge tearing from sharp groove edges | Inspect seal grooves for burrs or sharp edges (deburr if necessary) before installation; lubricate the seal surface with compatible grease (SHENKAI recommended type: SK-G-01) to prevent installation damage; ensure proper seating in the groove (no twisting or misalignment); replace if any signs of tearing, hardening, or chemical degradation are present |
3 | Seal-Adapeter Ring I.D. Lower | FH1835NL-10 | FH1835NL-10 | FH1835NL-10 | FH2321NL-11-00 | FH2821NL-10-00 | Same as Seal-Adapeter Ring I.D. Upper, with additional anti-extrusion ribs for high-pressure models (FH1835/70NL) | Same as upper adapter ring, plus increased pressure-induced extrusion risk for FH1835/70NL; wear from contact with wellbore fluids | Same as upper adapter ring; for FH1835/70NL, verify anti-extrusion ribs are intact before installation; monitor for leakage during pressure testing (conduct API 16A pressure test after installation) |
4 | Seal-Piston O.D. | FH1835NL-16 | FH1835NL-16 | FH1835NL-16 | FH2321NL.15-00 | FH2821NL.15-00 | U-cup seal: NBR/FKM composite for dynamic sealing; reinforced with PTFE insert for low friction | Dynamic wear from piston reciprocation; contamination-induced scoring; compression set; chemical attack from hydraulic fluid breakdown products | Replace all dynamic piston seals as a set (do not mix old and new seals); maintain hydraulic fluid quality (定期 test for moisture, acidity, and contamination); inspect piston surface for scratches that could damage the seal; lubricate the seal with hydraulic fluid before installation; avoid over-tightening during assembly to prevent seal distortion |
5 | O ring | FH1835NL-04 | FH1835NL-04 | FH1835NL-04 | FH2321NL-05 | FH2821NL-06 | NBR for standard applications (temperature range: -20°C to 120°C); FKM for high-temperature/high-chemical exposure (temperature range: -15°C to 200°C) | Extrusion into gland gaps; chemical degradation; thermal aging; surface damage from improper installation | Select the correct material based on operating temperature and fluid type; ensure gland dimensions meet SHENKAI OEM specifications (prevent extrusion); inspect O-ring for nicks, cuts, or swelling before use; store in sealed plastic bags to prevent dust and moisture contamination |
6 | O ring | FH1835NL-07 | FH1835NL-07 | FH1835NL-07 | FH2321NL-08 | FH2821NL-08 | Same as above, with different cross-sectional diameter (refer to model-specific drawings for dimensions) | Same as above; additional risk of misalignment in larger gland sizes | Same as above; use alignment tools during installation for larger O-rings to prevent twisting; verify gland depth and width before assembly |
3. Wear-Resistant Components
Wear-resistant components are designed to protect critical structural and sealing parts from abrasive wear, corrosion, and mechanical damage caused by drilling fluids, wellbore debris, and dynamic component movement. These components act as sacrificial barriers, extending the service life of more expensive primary components (e.g., piston, shell). Inadequate wear resistance can lead to premature failure of adjacent parts, increasing maintenance costs and operational risks.
Value Proposition: SHENKAI’s wear-resistant components are manufactured from high-hardness materials with superior abrasion and corrosion resistance properties. Their precision fit ensures optimal protection of primary components, reducing maintenance frequency and total ownership costs. OEM design guarantees compatibility with NL series BOPs, ensuring seamless integration and reliable performance.
No. | Description | FH1821NL Part No. | FH1835NL Part No. | FH1835/70NL Part No. | FH2321NL Part No. | FH2821NL Part No. | Material Specification | Primary Wear Causes | Maintenance & Handling Precautions |
1 | Wear Ring Adapter Ring | FH1835NL-08 | FH1835NL-08 | FH1835NL-08 | N/A | N/A | Reinforced phenolic resin with glass fiber; surface hardness ≥ HB 350 | Abrasive wear from wellbore debris; impact damage from large particles; thermal degradation at high temperatures; cracking from uneven pressure distribution | Inspect for cracks, chipping, or excessive wear (replace if wear depth exceeds 2mm); clean surface debris regularly to prevent abrasive buildup; avoid contact with high-temperature surfaces (limit exposure to ≤ 120°C); handle with care during installation to prevent chipping edges |
2 | Wear Ring Piston O.D. | FH1835NL-15 | FH1835NL-15 | FH1835NL-15 | FH2321NL-16 | FH2821NL-14 | PTFE (polytetrafluoroethylene) with carbon fiber reinforcement; low friction coefficient (≤ 0.15) | Abrasive wear from dynamic piston movement; contamination-induced scoring; deformation at high temperatures; extrusion under high pressure | Check radial clearance regularly (maintain 0.05-0.10mm for optimal performance); replace if wear causes clearance to exceed 0.20mm; ensure hydraulic fluid is free of abrasive particles; avoid overheating the piston assembly (monitor hydraulic fluid temperature ≤ 60°C) |
3 | Wear Ring Shell | FH1835NL-12 | FH1835NL-12 | FH1835NL-12 | FH2321NL-13 | FH2821NL-13 | High-nickel alloy (Inconel 625) for corrosion resistance; hardfaced with Stellite 6 (hardness ≥ HRC 58) for abrasion resistance | Abrasive wear from drilling fluid flow; erosion-corrosion from acidic fluids; thermal fatigue from temperature fluctuations; impact damage from wellbore debris | Inspect hardfacing for cracks or wear using MPI annually; measure wear thickness (replace if hardfacing thickness ≤ 0.5mm); clean the wear ring surface regularly to remove debris buildup; for offshore applications, apply additional anti-corrosion coating to external surfaces |
4. Fastening & Auxiliary Components
Fastening & auxiliary components ensure the secure assembly and proper functioning of the annular BOP, including retaining parts in place, providing fluid passage, and preventing unintended disassembly. These components are subjected to high tensile loads, vibration, and corrosion. Failure of fasteners (e.g., studs, cap nuts) or auxiliary parts (e.g., plugs, retainer rings) can lead to component disassembly under pressure, seal leakage, and loss of well control.
Value Proposition: SHENKAI’s fastening components are manufactured from high-tensile alloy steels meeting API 8C standards, ensuring reliable load-bearing capacity and resistance to fatigue. Auxiliary components are precision-machined to OEM specifications, guaranteeing compatibility and optimal performance. Using genuine fastening and auxiliary parts minimizes the risk of assembly failure and ensures compliance with safety regulations.
No. | Description | FH1821NL Part No. | FH1835NL Part No. | FH1835/70NL Part No. | FH2321NL Part No. | FH2821NL Part No. | Material Specification | Primary Wear Causes | Maintenance & Handling Precautions |
1 | Adapter Ring | FH1835NL-05 | FH1835NL-05 | FH1835NL-05 | FH2321NL-06 | FH2821NL-07 | AISI 4140 alloy steel, precision-machined for dimensional accuracy | Thread wear from repeated assembly/disassembly; corrosion; uneven stress distribution; impact damage | Inspect threads for wear, galling, or corrosion before assembly; use thread locker (Loctite 243 recommended) for vibration resistance; torque to SHENKAI OEM specifications; avoid over-torquing, which can cause thread stripping or component deformation |
2 | Cap Nut | FH2321NL-03 | FH2321NL-03 | FH2321NL-03 | FH2321NL-03 | FH2821NL-04 | High-tensile alloy steel (grade 8.8), heat-treated for strength | Thread wear; corrosion; fatigue fracture from cyclic loading; loosening due to vibration | Inspect for corrosion, thread damage, or fatigue cracks regularly; use a torque wrench to ensure proper tightening (refer to model-specific torque values); check tightness after thermal cycling or high-vibration operations; replace if any signs of damage or fatigue are present |
3 | Stud | FH1835NL-03 | FH1835NL-03 | FH1835NL-03 | FH2321NL-04 | FH2821NL-03 | Alloy steel (grade 10.9), meeting API 8C standards for high tensile strength | Fatigue fracture; thread wear; corrosion; bending stress from misalignment | Conduct MPI for fatigue cracks annually; replace studs after 5 assembly/disassembly cycles or if any signs of damage are present; ensure proper alignment during installation to prevent bending; use hardened washers to distribute load evenly |
4 | Plug | FH2835-22 | FH2835-22 | FH2835-22 | FH2835-22 | N/A | AISI 316 stainless steel (corrosion-resistant) with NBR O-ring seal | Thread wear; corrosion (especially in offshore environments); O-ring degradation; loosening due to vibration | Inspect O-ring for wear or degradation before installation; apply anti-seize compound to threads for corrosion resistance; torque to recommended values; check for leakage during pressure testing; for offshore use, inspect monthly for corrosion |
5 | Adapter substitute | N/A | N/A | N/A | N/A | N/A | Not applicable (reserved for special customization) | N/A | Contact SHENKAI technical support for customization requirements and compatibility verification |
Procurement & Technical Compliance Guidance
Maintaining the safety and reliability of your SHENKAI NL series annular BOP requires strict adherence to OEM specifications when selecting and replacing parts. Compromising on part quality—such as using non-genuine seals, low-grade fasteners, or incompatible wear components—can lead to premature equipment failure, non-compliance with API 16A standards, and severe safety risks.
Procurement Criteria: 1) Verify part numbers against this catalog to ensure compatibility with your specific NL series model (FH1821NL, FH1835NL, etc.); 2) Request material certification and API 16A compliance documentation from suppliers; 3) Prioritize parts manufactured to SHENKAI OEM standards to guarantee fit and performance; 4) Avoid substituting components without written approval from SHENKAI technical engineering.
Technical Troubleshooting Reference: For common annular BOP issues (e.g., seal leakage, slow actuation, uneven wear), refer to the maintenance precautions in each component category. Key troubleshooting steps include: 1) Inspecting seals for wear or chemical degradation; 2) Verifying hydraulic fluid cleanliness and pressure; 3) Checking fastener torque and alignment; 4) Inspecting wear components for excessive damage.
Call to Action
Ensure your drilling operations remain compliant, safe, and efficient by sourcing genuine SHENKAI NL series annular BOP parts. Whether you require a high-performance packer for FH1835/70NL, wear-resistant rings for FH2321NL, or critical fastening components for FH2821NL, our team is ready to assist with your procurement needs. Contact us today with your specific part numbers and BOP model to secure high-quality, OEM-compatible replacements that meet the strictest industry standards. Investing in genuine parts is an investment in the safety and productivity of your drilling operations.
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