Find HS Code and trade information for expansion & overflow tanks&caps

Expansion & Overflow Tanks & Caps

Expansion and overflow tanks, often used in conjunction with radiator caps, are crucial components in liquid-cooled systems, primarily found in internal combustion engines, but also utilized in hydronic heating systems and other applications requiring fluid volume management. They serve to accommodate changes in fluid volume due to temperature fluctuations and maintain system pressure.

Purpose

The primary purpose of these components is to prevent damage to the cooling system caused by expansion and contraction of the coolant. Coolant volume increases as it heats up and decreases as it cools. Without accommodation for this change, excessive pressure could build up, leading to burst hoses, radiator damage, or leaks. Conversely, a vacuum can form as the coolant cools, potentially causing cavitation and reducing cooling efficiency.

Function

• Expansion Tank: This tank provides a reservoir for the expanding coolant. As the coolant heats up, it flows into the expansion tank, preventing pressure buildup. When the engine cools, the coolant contracts, and the tank allows fluid to be drawn back into the radiator to maintain the correct coolant level.
• Overflow Tank: Similar to expansion tanks, overflow tanks collect excess coolant. However, they are typically simpler in design and often vented to atmosphere or to a recovery system.
• Radiator Cap: The radiator cap seals the cooling system, maintaining pressure. It incorporates a pressure relief valve to vent excess pressure to the overflow tank and a vacuum valve to allow fluid return. The cap’s pressure rating is critical for system operation.

Usage Scenarios

• Automotive Cooling Systems: The most common application. Expansion/overflow tanks are found in gasoline, diesel, and hybrid vehicles.
• Hydronic Heating Systems: Used in boilers and hot water systems to accommodate thermal expansion and contraction of the water.
• Industrial Cooling Systems: Used in machinery and equipment requiring liquid cooling.
• Solar Water Heating Systems: Manage fluid volume changes due to temperature variations in solar collectors.

Common Types

• Pressurized Expansion Tanks: These tanks are sealed and maintain a specific pressure within the cooling system. They are typically used in automotive applications. Subtypes include:
  • Diaphragm Expansion Tanks: Feature a rubber diaphragm separating the coolant from compressed air. This prevents direct contact between the coolant and the air, reducing corrosion.
  • Bladder Expansion Tanks: Similar to diaphragm tanks, but utilize a bladder instead of a diaphragm.
• Non-Pressurized Overflow Tanks: These tanks are vented to atmosphere and are often used in older vehicles or simpler systems.
• Translucent/Opaque Tanks: Translucent tanks allow visual inspection of coolant level and condition. Opaque tanks require level sensors or dipsticks.
• Radiator Caps:
  • Standard Pressure Caps: Designed for specific pressure ratings (e.g., 13 psi, 16 psi).
  • High-Performance Caps: Offer higher pressure ratings for modified cooling systems.
  • Stant Caps: A common brand known for quality and reliability.

Expansion and overflow tanks and caps can be classified under several HS codes based on their material and capacity, as detailed below:

• 7309000030: This HS code covers reservoirs, tanks, vats, and similar containers for any material (other than compressed or liquefied gas), made of iron or steel, with a capacity exceeding 300 liters. These containers are not fitted with mechanical or thermal equipment and may or may not be lined or heat insulated. Example: Large steel tanks used for storing liquids in industrial settings. The total tax rate is 80.0%, comprising a basic tariff of 0.0% and an additional tariff of 25.0%, increasing to 30.0% after April 2, 2025, plus a 25% additional tariff on steel/aluminum products.

• 7309000090: This HS code applies to reservoirs, tanks, vats, and similar containers made of iron or steel, exceeding 300 liters in capacity, not equipped with mechanical or thermal equipment, and regardless of lining or insulation. Example: Steel storage tanks. The total tax rate is 80.0%, consisting of a basic tariff of 0.0% and an additional tariff of 25.0%, rising to 30.0% after April 2, 2025, with a 25% additional tariff on steel/aluminum products.

• 7310100090: This HS code covers tanks, casks, drums, cans, boxes, and similar containers made of iron or steel, with a capacity of 50 liters or more, not fitted with mechanical or thermal equipment. Example: Steel drums used for transporting chemicals. The total tax rate is 80.0%, including a basic tariff of 0.0% and an additional tariff of 25.0%, increasing to 30.0% after April 2, 2025, plus a 25% additional tariff on steel/aluminum products.

• 7310290065: This HS code applies to tanks, casks, drums, cans, boxes, and similar containers made of iron or steel, with a capacity of less than 50 liters, not equipped with mechanical or thermal equipment. Example: Small steel containers used for storing liquids. The total tax rate is 80.0%, comprising a basic tariff of 0.0% and an additional tariff of 25.0%, increasing to 30.0% after April 2, 2025, plus a 25% additional tariff on steel/aluminum products.

• 3923300090: This HS code covers carboys, bottles, flasks, and similar articles made of plastics. Example: Plastic bottles used for storing liquids. The total tax rate is 58.0%, consisting of a basic tariff of 3.0% and an additional tariff of 25.0%, increasing to 30.0% after April 2, 2025.

• 3923500000: This HS code covers stoppers, lids, caps, and other closures made of plastics. Example: Plastic caps used to seal bottles. The total tax rate is 60.3%, consisting of a basic tariff of 5.3% and an additional tariff of 25.0%, increasing to 30.0% after April 2, 2025.

Regarding HS codes 7309000030, 7309000090, 7310100090, and 7310290065, please note the need to verify the material (steel or aluminum) and be aware of the additional 25% tariff applicable to steel/aluminum products.