Shenkai Annular BOP 7 1/16” x 5000 Psi (FH1835) Replacement Parts

1

Bonnet

FH1835NL-01

Forged alloy steel (4140), heat-treated, anti-corrosion coated to resist well fluids

1. Stress fatigue from repeated pressure cycles; 2. Corrosion from acidic wellbore fluids; 3. Thread damage during assembly/disassembly.

1. Torque per API 16A specifications during installation; 2. Inspect for cracks annually via NDT; 3. Apply anti-corrosion grease to threads before assembly.

2

Shell

FH1835NL-13

High-strength alloy steel (4340), forged, pressure-tested to exceed 35MPa rated pressure

1. Internal wear from piston movement; 2. Corrosion from well fluid contamination; 3. Structural damage from overpressuring.

1. Never exceed 35MPa rated pressure; 2. Flush internal surfaces after each use; 3. Inspect for internal wear during routine maintenance.

3

Piston

FH1835NL-14

Alloy steel (17-4 PH), precision machined, hard chrome-plated for wear resistance

1. Abrasive wear from contaminated hydraulic fluid; 2. Seal groove damage from misalignment; 3. Corrosion from moisture in hydraulic systems.

1. Use filtered hydraulic fluid (ISO 12103 Class 18/15); 2. Align piston correctly during installation; 3. Inspect chrome plating for scratches regularly.

4

Adapter Ring

FH1835NL-05

Alloy steel (Q355B), precision ground to ensure seal alignment and pressure resistance

1. Wear from contact with adjacent components; 2. Corrosion from well fluids; 3. Deformation from uneven pressure distribution.

1. Check fitment before installation to avoid misalignment; 2. Clean thoroughly to remove debris; 3. Replace if signs of warping are detected.

1

Packer (Annular Rubber Core)

FH1835NL.02-00A（1）

High-performance nitrile butadiene rubber (NBR), reinforced with fabric, resistant to well fluids and high pressure

1. Abrasion from tubular movement; 2. Degradation from high temperature/pressure cycles; 3. Chemical attack from acidic well fluids.

1. Inspect for cracks/softening monthly; 2. Avoid contact with sharp tubular edges; 3. Replace after 12 months or 50 pressure cycles (whichever comes first).

2

Seal-Adapter Ring I.D. Upper

FH1835NL-06（1）

Fluororubber (FKM), high-temperature resistant (up to 200℃), compatible with well fluids

1. Compression set from long-term pressure; 2. Chemical degradation from well additives; 3. Damage during installation.

1. Install with proper tooling to avoid tearing; 2. Replace if compression set exceeds 20% (per ASTM D395); 3. Store in clean, dry conditions before use.

3

Wear Ring-Adapter Ring

FH1835NL-08（1）

Polytetrafluoroethylene (PTFE), reinforced with glass fiber, low-friction and wear-resistant

1. Abrasive wear from debris in well fluids; 2. Cracking from excessive pressure; 3. Misalignment causing uneven wear.

1. Clean mating surfaces before installation; 2. Ensure proper alignment to distribute load evenly; 3. Replace if wear exceeds 0.5mm.

4

Seal-Adapter Ring I.D. Lower

FH1835NL-10（1）

Fluororubber (FKM), oil and chemical resistant, designed for high-pressure sealing

1. Leakage from improper installation; 2. Degradation from high-temperature well fluids; 3. Wear from piston movement.

1. Verify seal size matches mating components; 2. Lubricate with compatible grease before installation; 3. Inspect for leaks after pressure testing.

5

Seal-Piston O.D.

FH1835NL-16（2）

Nitrile rubber (NBR), durable, compatible with hydraulic fluids and well chemicals

1. Abrasion from contaminated hydraulic fluid; 2. O-ring extrusion under high pressure; 3. Deterioration from moisture.

1. Use hydraulic fluid with ISO cleanliness Class 16/13; 2. Ensure seal grooves are free of burrs; 3. Replace if signs of extrusion or cracking appear.

6

Seal-Shell Upper

FH1835NL-09（1）

FKM rubber, high-pressure resistant, designed to seal between shell and bonnet

1. Leakage from bonnet misalignment; 2. Wear from repeated assembly/disassembly; 3. Chemical attack from well fluids.

1. Torque bonnet evenly to avoid misalignment; 2. Inspect seal after each disassembly; 3. Replace if seal surface is damaged.

7

Seal-Shell Lower

FH1835NL-11-00 (1)

FKM rubber, resistant to extreme pressure and temperature fluctuations

1. Degradation from long-term exposure to well fluids; 2. Cracking from thermal cycling; 3. Improper installation causing pinching.

1. Install without twisting the seal; 2. Protect from sharp edges during assembly; 3. Test seal integrity after installation per API 16A.

8

O-ring

FH1835NL-04（1）

NBR rubber, flexible, designed for low-pressure auxiliary sealing

1. Deterioration from ozone exposure; 2. Pinching during installation; 3. Swelling from incompatible fluids.

1. Store in ozone-free environment; 2. Use proper installation tools to avoid pinching; 3. Ensure compatibility with surrounding fluids.

9

O-ring

FH1835NL-07（1）

NBR rubber, oil-resistant, suitable for hydraulic system auxiliary sealing

1. Wear from component movement; 2. Swelling from hydraulic fluid contamination; 3. Aging from prolonged storage.

1. Replace stored O-rings every 24 months; 2. Filter hydraulic fluid regularly; 3. Inspect for swelling or hardening before use.

10

Wear Ring-Piston O.D.

FH1835NL-15（2）

PTFE, glass fiber reinforced, low friction, designed to protect piston seals

1. Abrasive wear from debris; 2. Cracking from excessive pressure; 3. Uneven wear from piston misalignment.

1. Clean piston and shell surfaces before installation; 2. Align wear ring with seal grooves; 3. Replace if cracked or heavily worn.

11

Wear Ring-Shell

FH1835NL-12（1）

PTFE, wear-resistant, reduces friction between shell and piston

1. Wear from repeated piston movement; 2. Damage from foreign debris; 3. Degradation from high temperatures.

1. Remove debris from shell before installation; 2. Inspect for wear during routine BOP maintenance; 3. Replace if friction increases noticeably.

1

Cap Nut

FH2321NL-03 (24)

Alloy steel (8.8 grade), galvanized, high-torque design for pressure-bearing applications

1. Thread wear from over-torque; 2. Corrosion from outdoor/oilfield exposure; 3. Loosening from BOP vibration.

1. Torque to 85–90 N·m per API 16A; 2. Apply anti-seize compound to threads; 3. Inspect torque monthly during routine checks.

2

Stud

FH1835NL-03 (24)

Alloy steel (10.9 grade), heat-treated, threaded for high-pressure component fastening

1. Thread galling during installation; 2. Fatigue from pressure cycles; 3. Corrosion from well fluids.

1. Use anti-galling compound on threads; 2. Replace studs after 3 assembly/disassembly cycles; 3. Inspect for thread damage before reuse.

3

Plug

FH2835-22（2）

Alloy steel (Q235B), galvanized, designed for auxiliary port sealing

1. Thread wear from repeated removal; 2. Corrosion from moisture; 3. Leakage from improper tightening.

1. Torque to 25–30 N·m; 2. Apply thread sealant before installation; 3. Replace if threads are stripped or damaged.

4

Adapter substitute

N/A

Alloy steel (Q355B), precision machined to match adapter ring fitment and pressure requirements

1. Wear from component contact; 2. Corrosion from well fluids; 3. Misalignment causing stress concentration.

1. Verify fitment with adjacent components; 2. Clean and inspect before installation; 3. Replace if signs of stress or wear are present.

What is the recommended replacement interval for the annular rubber core (FH1835NL.02-00A)?

Replace every 12 months or 50 pressure cycles (whichever comes first). For harsh conditions (acidic fluids, frequent tubular movement), shorten intervals to 6–8 months, per API 16A maintenance guidelines.

Which lubricant is compatible with FKM seals (e.g., FH1835NL-06, FH1835NL-10)?

Use silicone-based or fluorinated lubricants compatible with FKM rubber. Avoid petroleum-based greases, which cause seal degradation. Ensure lubricants meet API 16A compatibility standards for well control equipment.

How to resolve cap nut (FH2321NL-03) loosening on the BOP bonnet?

Retorque nuts to 85–90 N·m using a calibrated torque wrench, applying anti-seize compound to threads. Use a torque sequence that distributes load evenly (star pattern) and inspect torque monthly. Replace nuts if threads are worn or stripped.