API SPEC 16C Choke and Kill Hose


API SPEC 16C Choke and Kill Hose

API SPEC 16C is a flexible choke and kill hose. It is suitable for connection at locations where the drill platform, semi-submersible drilling vessel and installation dimensions of the drilling rig move relatively.

It is made up of inner core, double cross wireline layer, heat-insulation layer, fire resistance layer, buffering and sealing layers.

Pressure Range

M-I SWACO’s 15,000-psi VERSA-CHOKE technology was engineered for advanced well control applications. The flexible hose handles extreme temperatures and pressure ratings with a maximum choke pressure loss of 5 psi over a one-hour hold period.

- Heavy-duty, diamond-lapped tungsten carbide plates are honed to near-perfect flatness and rotated by the actuator fork for finite regulation of opening size from full-open to closed. A 17deg dead band overlap beyond the full-close position ensures closure against abrasive solids flow and pressure surges.

Extended-wear tungsten carbide sleeves increase in-service life, reduce the effects of abrasive solids and protect the API ring gasket from debris in the fluid return stream. A hardfaced shuttle nut and internal removable body sleeve stand up to the high-pressure abrasive conditions of frac operations.


Choke and kill systems are used in a variety of service conditions. Therefore, specific requirements cannot be specified for all applications. However, products conforming to this specification should be suitable for use in sour, moderately corrosive environments. When severe corrosion, abrasion, high temperatures or fluid compatibility problems are expected, the equipment manufacturer and end user should jointly determine an appropriate product selection to address these issues.

This specification uses decimal inch units for dimensions. Fractions are shown as well, but are also converted to decimal equivalents in Annex A. This specification incorporates by reference other API, industry and government standards. These referenced standards are essential for the functional interchangeability of the equipment produced.

Application Methods

In critical well kill applications, the ability to achieve a quick, reliable kill in one circulation reduces drillpipe schedule, boosts rig productivity, and eliminates costly pressure fluctuations. M-I SWACO’s SUPERCHOKE choke and kill system is designed to withstand severe service conditions with a dynamic shuttle, hardfaced wear sleeve, and tungsten carbide downstream sleeves that stand up to abrasive proppant flow.

Gage and test port connections are holes drilled and tapped into API equipment for internal pressure measurements or to test the sealing mechanisms. Typical test ports are located in the body and sleeve assemblies.

Hose Structure

4.1 General

Ring gaskets must be joined to API equipment with a minimum of positive interference to assure that the rings will seal in the flange grooves. Gaskets may not be reused.

The body, bonnet and stems of API equipment that contain well bore pressure shall be fabricated from materials listed in this section. These components must pass a Charpy V-notch impact test at a minimum of 20 ft-lb of impact force and be free of cracks and other imperfections.

All assembled equipment must have an API certificate of compliance with this specification. It must state the product specification level (PSL), material class and temperature rating selected from Table 4.

Material Advantages

API 16C choke and kill systems provide a way for operators to monitor well control system analog pressure gauges and hydraulic set-point regulators from the choke console. This removes the need for joystick adjustments during a kill operation, saving significant rig time and allowing crews to focus on critical well-control functions such as maintaining stand pipe pressure, monitoring casing pressure, and adjusting pump strokes.

Designed, manufactured and monogrammed in accordance with API Spec 6A and NACE MR0175. Optional third-party ABS CDS, DNV and CE marked certification available. High-capacity 3-in [76 mm] choke bore improves flow characteristics at the throttle point. Tungsten carbide downstream sleeves increase in-service life, reducing the effects of abrasive sand flow.

Precautions for Use

API 16C CHOKE AND KILL hose is used for flexible connection between the riser and manifold system of oilfield choke and kill manifold systems. It features armored, thermal insulation, high pressure resistance, anti-flaming and fire resistant inner wall and stainless steel jacket.

Its inner tube is made of oil resistant, acid and alkali resistance and wear-resistant neoprene rubber. Its reinforcement is made of 2-8 layers of single high strength steel wire winding. The outer protective layer is made of aging-resistant, weather proof and oil resistant stainless steel sheath/armor.

Applicable Fitings

Choke manifold (well control choke manifold) consists of choke valve, gate valve and pipeline etc. This device is adopted to execute the new drilling-wells technique of balance pressure, so it can make sure the well kick successfully.

Designed for air, oils, fats, gasoline and petroleum products. Also handles mild chemicals and water. Use push-on fittings and no clamps or special tools required. Non-conductive and MSHA approved.

Coflexip hose is armored with thermal insulation, high-pressure resistance, anti-flaming and fire resistant inner wall. Suitable for connection at locations when drill platform, semi-submersible drilling vessel or drilling vessel moves relatively and the installation dimensions of the drill rig subsequently change, to delivery oil, gas and mud.

Leave a Message