11-Inch 5,000 PSI Double Ram Blowout Preventer
Engineered for reliable well control in demanding onshore and offshore drilling environments.
Full technical specifications, interchangeable ram options, and global supply support.
Product Overview
The 11-inch 5,000 PSI Double Ram Blowout Preventer (BOP) is a critical piece of
wellhead pressure control equipment used across the global oil and gas industry. Combining two
independent ram cavities within a single forged alloy steel body, this BOP provides superior
well-control redundancy while minimizing the overall height of the stack — a key advantage on
space-constrained rigs and platforms.
Designed, tested, and certified in full compliance with API Specification 16A
(Drill-Through Equipment) and the equivalent GB/T 20174 standard, this BOP is
engineered to seal against high-pressure wellbore fluids, gases, and multi-phase flows encountered
during drilling, workover, and completion operations.
Each unit undergoes rigorous hydrostatic pressure testing, dimensional inspection, and full material
traceability before shipment, ensuring it is field-ready from the moment it arrives on location.
Technical Specifications
The following specification table reflects the core design parameters of the 11-inch 5,000 PSI
Double Ram BOP (Model Reference: 2FZ28-35). All values are nominal; consult
the official datasheet or contact our technical team for project-specific tolerances.
| Parameter | Value / Description |
|---|---|
| Model Reference | 2FZ28-35 (Shaffer / Cameron Style) |
| Bore Size (Nominal) | 11 inches (279.4 mm) |
| Working Pressure (WP) | 5,000 PSI (34.5 MPa) |
| Test Pressure | 7,500 PSI (51.7 MPa) |
| Number of Ram Cavities | 2 (Double / Dual Stack) |
| Hydraulic Control Pressure | 1,200 – 1,500 PSI (8.3 – 10.3 MPa) |
| Piston Size (Diameter) | 9.8 inches (248.9 mm) |
| Piston Stroke | 6.3 inches (160 mm) |
| Operating Temperature Range | -4°F to 186°F (-20°C to 86°C) |
| Body Material | Forged Alloy Steel |
| Ram Types Supported | Pipe Rams (2-3/8″–13-3/8″), Blind Rams, Blind-Shear Rams, VBR |
| Operation Mode | Hydraulic (primary) / Manual Lock (backup) |
| Top & Bottom Connections | API 16A Flanged (RX or BX ring groove) |
| Side Outlet Connections | Studded Flanges or Threaded (per project) |
| Locking Device | Standard: Manual Lock; Optional: Hydraulic Lock |
| Internal Fluid Passage | Integral (body-ported) hydraulic circuit |
| Approximate Weight | ~600 kg (1,323 lbs) |
| Applicable Standards | API Spec 16A (3rd Ed.) / GB/T 20174 |
| Quality System | ISO 9001 / API Monogram |
| Surface Finish | Industrial primer + topcoat (RAL color on request) |
* Specifications are subject to change. Always refer to the official spec sheet (PDF) for the most
current values before procurement.
Key Engineering Features
The 11-inch 5K Double Ram BOP integrates proven engineering design with robust materials to deliver
dependable performance across the full service life of the equipment.
Forged Alloy Steel Body
All pressure-bearing components are manufactured from high-quality forged alloy steel, providing
superior tensile strength, impact toughness, and resistance to hydrogen-induced cracking (HIC).
Floating Ram Seal Design
Floating or integral ram assemblies ensure positive, leak-free sealing against the wellbore.
The front seal and top seal are separated for greater redundancy and easier field replacement.
Dual Operating Modes
Hydraulic actuation at 1,200–1,500 PSI for remote, rapid closure. Built-in manual lock provides
fail-safe ram retention if hydraulic pressure is lost — a mandatory well-control backup.
Wide Temperature Rating
Qualified for service temperatures from -4°F (-20°C) to 186°F (86°C), covering the majority
of onshore drilling environments and moderate-temperature offshore applications.
Compact Double-Stack Configuration
Two ram cavities in one body reduce the total BOP stack height compared to two single-ram
preventers, lowering rig floor load and simplifying installation/handling.
Interchangeable Ram Assemblies
Compatible with a full range of ram types — pipe, blind, shear, and variable-bore — making
the same BOP body adaptable to multiple drilling programs without replacing the main housing.
Side-Entry Hinge Design
Load-bearing and hydraulic cylinder hinges are physically separated for a compact,
mechanically rigid structure that simplifies ram bonnet removal and maintenance on site.
Stainless-Lined Flange Grooves
Ring gasket grooves in all API flanges are lined with stainless steel to prevent corrosion
and ensure consistent sealing performance throughout the equipment’s service life.
Applications & Use Cases
The 11-inch 5,000 PSI Double Ram BOP is widely deployed across a broad range of drilling and
well-servicing environments where reliable pressure containment is non-negotiable.
Why Choose a Double Ram Configuration?
Compared to a single ram BOP, the double ram design provides two independent sealing barriers
within a single housing. Drillers can install pipe rams in one cavity and blind-shear rams in
the other, enabling both tubular-seal and full-bore-closure capability without adding additional
bodies to the stack. This reduces the total BOP stack height, lowers rig floor loading, and
simplifies manifold connections — all while meeting or exceeding the well-control requirements
of IADC, API, and operator well-construction standards.
Compliance & Certifications
All 11-inch 5K Double Ram BOPs supplied by our facility are manufactured under a rigorously
controlled quality management system and certified to the following international standards:
- API Specification 16A (3rd Edition) — Specification for Drill-Through Equipment. The gold standard for all ram and annular BOPs used globally.
- GB/T 20174 — Chinese National Standard equivalent to API 16A, required for operations in PRC-regulated oilfields.
- ISO 9001:2015 — Quality Management System certification covering design, manufacturing, inspection, and after-sales support.
- API Monogram Program — Products manufactured under the API Monogram License carry the API mark, signifying full conformance with API 16A design and production requirements.
Testing & Inspection
Every BOP unit undergoes the following mandatory acceptance tests before release from the facility:
- Hydrostatic shell (body) pressure test to 7,500 PSI (150% of WP)
- Ram seal and side-door seal leak tests at rated working pressure
- Hydraulic actuator function test (full open / full close cycle verification)
- Manual lock engagement and retention test
- Full dimensional inspection per API 16A dimensional requirements
- Material traceability documentation (MTR / Mill Test Reports) for all pressure parts
Frequently Asked Questions
What is a Double Ram Blowout Preventer (BOP)?
A Double Ram BOP contains two stacked sets of ram cavities within a single body. Each cavity can
hold a different ram type — for example, pipe rams on top and blind-shear rams on the bottom — giving
the driller two independent well-control barriers in a compact, single-body package. This is more
space-efficient than stacking two separate single-ram BOPs and reduces overall BOP stack height.
Which API standard governs this BOP?
This BOP is designed, manufactured, and tested in accordance with API Specification 16A
(Specification for Drill-Through Equipment, 3rd Edition) and the equivalent Chinese national standard
GB/T 20174. Third-party inspection reports, material test records, and API Monogram documentation are
available upon request.
What drill pipe and casing sizes are compatible?
With an 11-inch bore, this BOP accommodates pipe rams sized from 2-3/8 inches to 13-3/8 inches OD,
covering the full range of drill pipe, drill collars, tubing, and intermediate casing strings commonly
used in wells with this bore size. Variable-bore rams (VBR) can seal across a range of tubular ODs
without changing rams.
What happens if hydraulic pressure fails?
The BOP is equipped with a standard manual locking device on each ram bonnet. In the
event of hydraulic system failure, the operator can manually rotate the locking stem to mechanically
secure the rams in the closed position, maintaining well containment. Optional hydraulic lock systems
are available for remote-operated or subsea configurations.
Is this BOP suitable for H₂S (sour gas) service?
A standard configuration is designed for sweet-service applications. For sour-gas (H₂S) environments,
a NACE MR0175 / ISO 15156 compliant variant is available, featuring materials and
elastomers specifically qualified for hydrogen sulfide exposure. Please specify sour-service requirements
when requesting a quotation.
What lead time and shipping options are available?
Standard units are typically available from stock or within 6–10 weeks for new
manufacture, depending on configuration. International shipping by sea freight (CIF or FOB) or air
freight (for urgent requirements) is available. All units are packed in export-grade plywood crates
with moisture protection for ocean transit.
Why Source from Us?
We are a specialist supplier of API 16A certified wellhead and pressure control equipment, serving
E&P operators, drilling contractors, and oilfield service companies across six continents.
- Certified Quality: All BOPs carry API Monogram and ISO 9001 certification, with full documentation packages provided at delivery.
- Global Inventory: Stock units and fast-track production available to meet urgent rig requirements worldwide.
- Technical Support: In-house application engineering team for specification review, stack-up configuration assistance, and HAZID documentation.
- Aftermarket Spares: Full range of OEM-compatible ram rubbers, seal kits, piston seals, and bonnet assemblies available ex-stock.
- Competitive Pricing: Factory-direct sourcing and lean production practices deliver significant cost savings versus legacy brand pricing.
- Proven Track Record: Deployed on active rigs across the Middle East, Southeast Asia, Central Asia, Africa, and the Americas.
