Master Distributors of Oil Tools World Petroleum Supply, Inc.



World Petroleum Supply stocks National Oilwell Varco the top industry manufacturer Blow Out Preventers (BOP).

National Oilwell Varco Manual Lock Model SLX Ram BOP

The National Oilwell Varco manual lock Model SLX ram blowout preventer provides a rugged, reliable preventer that is easily serviced in the field. Special features include:

  • New door design is a lighter and shorter profile than earlier models. The simple SLX door design provides less stress and easy maintenance.
  • Doors on the BOP are interchangeable.
  • Booster assemblies can be added easily to the new design
  • Flat doors to simplify ram changes.
  • New design cartridge seal assembly employs a radial seal to pressure-assist a face seal and prevent extrusion. This feature allows reduced door bolt torque.
  • Hinge bracket redesign has added needle roller thrust bearings. The force required to move the door from open to close and vice versa has been reduced significantly.
  • Body design utilizes a space-saving ram cavity design. BOP heights and weights have been optimized using finite element analysis. Body to door interface surfaces are polymer coated to minimize corrosion.
  • Ram shafts are nickel plated for corrosion and improved wear characteristics. Standard internal H2S trim.
  • Lip-type ram shaft seals to hold the wellbore pressure and the opening hydraulic pressure.
  • Secondary ram shaft seals to permit injection of plastic packing if the primary liptype seal ever fails.

The manual lock SLX BOP is available in single and double models. (Contact World Petroleum Supply Sales for special configurations.) This manual provides the installation, operation, and maintenance procedures for the SLX BOP model with 15.25” manual locking cylinders. See Figure 2-1 on right

Shaffer® Manual Lock SL  Standard BOP Blowout Preventer buy at Oilfield Distributor - World Petroleum Supply.

These BOPs are designed for drilling and workover service. They are hydraulically operated and can be manually locked by turning handwheels. The standard trim unit is suitable for internal H2S environments. Units can be manufactured for Arctic (to -75° F or -59° C) and full H2S environmental services. Standard units can be retrofitted for full environmental H2S service. Shaffer preventers are manufactured in accordance with the American Petroleum Institute (API) specification 16A (third edition) and the National Association of Corrosion Engineers (NACE) document NACE Standard MR 01 75. Hydraulic pressure of 1,500 psi (103 bar) will close any model SLX ram BOP with its rated wellbore pressure or less. Maximum of 3,000 psi (207 bar) can be used. The specifications and dimensions given are for the 13 5/8” 10,000 psi manual lock SLX. The Shaffer model SLX ram BOP can be supplied with booster cylinders if required. See Figure 2-1 on Page 2-2.

Safety Precautions

Exposure to the daily hazards of drilling can lead rig crews and service personnel to disregard or overlook hidden hazards. The safety precautions listed below should be observed at all times.

Equipment Repairs or Adjustments

Turn off the system power and bleed all pressure prior to making any repairs or adjustments that do not require system power.

Hydraulic Lines

Hydraulic lines carrying fluids at high pressures can inflict potentially fatal injuries if the pressure escapes. Protect hydraulic lines from cutting, scraping, pinching, or other physical damage. Always wear hard hats and safety glasses when working around hydraulic lines. Bleed the pressure from any hydraulic line prior to disconnecting any fittings. Respect the prescribed ASME code minimum bend radius for hydraulic lines. Bending around too short a radius can rupture the line.

Welding and Cutting

Do not weld or operate acetylene-cutting torches near unprotected electrical cable, flexible hose, or hose bundles. Weld spatter can seriously damage the hose or cable. Ensure no slag or spatter enters the hydraulic system.

Replacement Parts

Many of the BOP components, though apparently similar to commercial hardware, are manufactured to system design specifications. To avoid possible hazardous failures, use only exact replacement parts or assemblies. Contact World Petroleum Supply for details.

View Packing Elements and Seal Kits from World Petroleum Supply.


World Petoleum Supply, Inc. stocks the top oilfield manufactures for the Rig Floor, Flow Control and Pressure Control products.