Understanding the individual components of a ram blowout preventer is essential for engineers, drilling supervisors, and procurement professionals who need to specify, operate, or maintain this critical well control equipment. This guide provides a thorough, component-by-component breakdown of a typical WU-series double ram BOP as manufactured by CAMTOP Shanghai Machinery Equipment Co., Ltd.

1. Main Body (Housing)

The main body is the central pressure-containing structure of the ram BOP. CAMTOP manufactures WU-series bodies from forged alloy steel (typically AISI 4130 equivalent or higher), which provides superior strength, toughness, and resistance to hydrogen-induced cracking (HIC) compared to cast materials.

  • Top and bottom flanges machined to API 16A / API 6A RX or BX ring joint face specifications
  • Stainless steel ring groove overlay for corrosion resistance
  • Precisely machined ram guides to ensure alignment of ram assemblies

2. Bonnet Assemblies

The bonnets are the side doors of the BOP. CAMTOP WU-series bonnets use a split-hinge design where the load-bearing hinge and the hydraulic cylinder hinge are separated. This allows the bonnet to swing fully open for ram access without disconnecting hydraulic lines, significantly reducing maintenance downtime on the rig.

3. Hydraulic Cylinder Operators

The hydraulic operators provide the closing and opening force to actuate the rams. They are double-acting cylinders rated for 1,200–1,500 PSI hydraulic control pressure. Per API 16A, rams must close within ≤30 seconds at rated pressure.

4. Ram Assemblies

Ram assemblies are the core sealing elements. Each cavity accepts one pair of rams. Ram assemblies are interchangeable within the same bore size and working pressure rating.

Ram Type Application Pipe Size Range
Pipe Ram Seal on specific pipe OD 2-3/8″ to 13-3/8″
Variable Bore Ram (VBR) Seal on a range of pipe ODs 3-1/2″ to 7″ (typical)
Blind Ram Seal open hole (no pipe) N/A
Shear Blind Ram Cut pipe and seal open hole Shears standard API drill pipe

5. Ram Packing (Sealing Elements)

Ram packing provides the primary pressure seal. CAMTOP supplies complete standard and large-bore bonnet softgoods kits for all WU-series BOPs, including:

  • Standard Service: Nitrile (NBR) rubber — up to 100°C
  • H₂S / Sour Service: Hydrogenated Nitrile (HNBR) — per NACE MR0175
  • High Temperature: Fluorocarbon (FKM/Viton) — up to 175°C

6. Manual Lock Mechanisms

Manual lock screws allow rams to be locked in the closed position without hydraulic pressure. To lock, turn the hand wheel clockwise after hydraulically closing the rams.

⚠️ Safety Note: Always verify manual locks are fully retracted before attempting to hydraulically open the rams.

Maintenance Intervals

Maintenance Task Interval
Visual inspection of packing and seals After every well or 6 months
Function test (open/close) Before each well, per API RP 53
Complete disassembly and softgoods replacement Every 2–3 years or per OEM recommendation
Non-destructive testing (NDT) of body Every 5 years or per regulatory requirement

Need parts, softgoods kits, or technical manuals for your CAMTOP BOP? Contact us: sales@cposl.com | +86.21.58432768 | www.camtop-oilfieldtools.com/