Platform Tensioner Cylinder Assembly

Hydraulic tensioner cylinders maintain constant tension on offshore drilling risers to compensate for vessel heave motion on floating platforms (HTS 8431.43.40.00). Integral to 8430.41/8430.49 boring machinery for deepwater operations. Classified as parts solely for offshore oil and gas production platforms.

Import Duty Rates by Country of Origin

Origin CountryMFN RateCh.99 SurchargesTotal Effective Rate
🇨🇳ChinaFree+35.0%35%
🇲🇽MexicoFree+10.0%10%
🇨🇦CanadaFree+10.0%10%
🇩🇪GermanyFree+10.0%10%
🇯🇵JapanFree+10.0%10%

Alternative Classifications

This product could be classified differently depending on its characteristics or intended use.

8412.21.00Same rate: 35%

If imported as general industrial hydraulic cylinders

Pneumatic/hydraulic linear cylinders default to 8412 when not specifically adapted as principal parts of offshore drilling platforms.

8431.43.80.40Same rate: 35%

If for tensioners of other offshore machinery

Other offshore boring parts not tensioners go to 8431.43.8040/8060 subheadings.

Not sure which classification is right?

Our AI classifier can analyze your specific product and recommend the correct HTS code with confidence.

Import Tips & Compliance

Include stroke length and tension capacity specs (e.g

1M lbs/line); require DNV-GL or ABS type approval for marine use; avoid bulk hydraulic cylinder imports under 8412

Related Products under HTS 8431.43.40.00

BOP Stack Assembly for Offshore Platforms

A blowout preventer (BOP) stack assembly is a critical safety component designed specifically for offshore oil and natural gas drilling platforms under HTS 8431.43.40.00. It consists of multiple ram and annular preventers mounted on a manifold to seal the wellbore during drilling operations on floating or fixed platforms. Classified here as a part solely for boring machinery of subheading 8430.41 or 8430.49 used offshore.

Offshore Drilling Riser Joint

A marine riser joint connects sections of the riser string used in offshore drilling platforms to convey drilling fluid and guide tools between the rig and subsea wellhead (HTS 8431.43.40.00). These high-pressure, corrosion-resistant pipes are engineered for deepwater environments on platforms using 8430.41/8430.49 boring machinery. Essential for maintaining well control during offshore operations.

Subsea Wellhead Connector

A high-pressure subsea wellhead connector mates the offshore platform's blowout preventer stack to the subsea wellhead in oil and gas drilling operations (HTS 8431.43.40.00). Designed for extreme deepwater pressures and remote operation via ROVs on 8430.41/8430.49 platforms. Classified as a principal part for offshore boring machinery.

Offshore Derrick Crown Block

The crown block is the fixed sheave assembly at the top of an offshore drilling derrick/platform, guiding the drilling line for hoisting operations (HTS 8431.43.40.00). Built to withstand extreme loads on floating production platforms using 8430.41/8430.49 boring equipment. A principal mechanical part for offshore oil/gas drilling rigs.

Top Drive Gearbox Module

The gearbox module within an offshore top drive system transmits power to rotate the drill string on oil/gas platforms (HTS 8431.43.40.00). Designed for harsh marine environments and high-torque requirements of 8430.41/8430.49 boring rigs. A key power transmission part solely for offshore drilling.

Mud Pump Fluid End Section

The fluid end section of high-pressure mud pumps circulates drilling fluid through offshore platform systems for 8430.41/8430.49 boring machinery (HTS 8431.43.40.00). Contains pistons, valves, and liners exposed to abrasive drilling mud at 5,000+ psi. Exclusive to offshore oil/gas drilling platforms.