| HS Code | Official Doc | Tariff Rate | Origin | Destination | Effective Date |
|---|---|---|---|---|---|
| 8414596540 | Doc | 57.3% | CN | US | 2025-05-12 |
| 8414901080 | Doc | 59.7% | CN | US | 2025-05-12 |
| 8479899599 | Doc | 57.5% | CN | US | 2025-05-12 |
| 8479899599 | Doc | 57.5% | CN | US | 2025-05-12 |
| 8543708000 | Doc | 55.0% | CN | US | 2025-05-12 |
| 8543906800 | Doc | 55.0% | CN | US | 2025-05-12 |
Fan Governor
A fan governor, also known as a centrifugal governor or Watt governor, is a mechanical device used to automatically regulate the speed of an engine, typically a steam engine, by controlling the fuel or steam supply. It maintains a nearly constant speed despite variations in load.
Material
Fan governors are primarily constructed from:
- Metal: Typically cast iron, steel, or brass for the frame, weights, and linkages due to their durability and ability to withstand mechanical stress.
- Linkages: Steel or brass rods and pivots connecting the components.
- Sleeve/Spindle: Steel, providing a smooth rotating surface.
- Springs: Steel coil springs used for tension and responsiveness.
Purpose
The primary purpose of a fan governor is to:
- Speed Regulation: Maintain a consistent engine speed under varying loads.
- Prevent Overspeeding: Protect the engine from damage caused by excessive speed.
- Automated Control: Reduce the need for manual intervention in engine speed control.
Function
The governor operates based on the principle of centrifugal force. Here’s a breakdown of the process:
- Rotating Weights: Two or more weights are attached to a rotating spindle driven by the engine.
- Centrifugal Force: As the engine speed increases, the weights move outwards due to centrifugal force.
- Sleeve Movement: The outward movement of the weights is translated into a vertical movement of a sleeve connected to them via linkages.
- Linkage Control: The sleeve’s movement is connected to a control mechanism (e.g., a throttle valve or steam valve).
- Feedback Loop:
- Increased Speed: Higher speed causes the sleeve to rise, reducing the fuel/steam supply, thereby slowing down the engine.
- Decreased Speed: Lower speed causes the sleeve to fall, increasing the fuel/steam supply, thereby speeding up the engine.
This creates a negative feedback loop that automatically adjusts the fuel/steam supply to maintain a desired speed.
Usage Scenarios
Fan governors were historically crucial in:
- Steam Engines: Used extensively in locomotives, stationary engines, and steam turbines.
- Water Pumps: Maintaining consistent pumping rates.
- Mills & Factories: Regulating the speed of machinery powered by steam engines.
- Early Internal Combustion Engines: Though less common now, early gasoline engines utilized governor principles.
Common Types
- Watt Governor: The original and most recognizable type, employing two rotating weights.
- Porter Governor: An improvement over the Watt governor, using adjustable weights for more precise control.
- Proell Governor: Designed for higher speeds and greater sensitivity.
- Governors with Dashpots: Incorporate damping mechanisms (dashpots) to reduce oscillations and improve stability.
Based on the provided information, the following HS codes may be relevant to “fan governor”:
- 8414596540: This HS code falls under Chapter 84, which covers “Air or vacuum pumps, air or other gas compressors and fans”. Specifically, it covers “Fans: Other: Other Suitable for use with motor vehicles”. A fan governor is a component used with fans, and if it's designed for use in motor vehicles, this code may apply. The total tax rate is 57.3%, comprised of a 2.3% base tariff, a 25.0% additional tariff, and a 30.0% additional tariff effective April 2, 2025.
- 8414901080: Also within Chapter 84, this code covers “Parts: Of fans (including blowers) and ventilating or recycling hoods Other”. Since a fan governor is a part of a fan, this code is potentially applicable. The total tax rate is 59.7%, consisting of a 4.7% base tariff, a 25.0% additional tariff, and a 30.0% additional tariff effective April 2, 2025.
- 8479899599: This HS code is under Chapter 84, covering “Machines and mechanical appliances having individual functions, not specified or included elsewhere in this chapter; parts thereof: Other machines and mechanical appliances: Other: Other Other”. If the fan governor is considered a machine with an individual function not specifically covered elsewhere, this code could be relevant. The total tax rate is 57.5%, with a 2.5% base tariff, a 0.0% additional tariff, and a 30.0% additional tariff effective April 2, 2025, plus a 25% additional tariff for steel or aluminum products.
According to the provided reference material, the HS code options related to 'fan governor' are limited, with only the following 3 found.
Regarding HS code 8479899599, please note the need to verify if the product is made of steel or aluminum, as there is an additional 25% tariff for those materials.