What Is a Wet Line Kit on a Semi Truck?

A wet line kit on a semi truck is a set of components that allow the vehicle to transport liquid cargo such as oil, fuel, and other petroleum products. This system is an essential component of any long-haul trucking operation, as it provides the means to safely and efficiently move large amounts of liquid cargo. The wet line system consists of several elements, each of which must be properly maintained for optimal performance.

The first component of the wet line system is the hydraulic pump. This is a device that uses hydraulic pressure to force liquid through a hose or pipe.

The pump can be powered by either an electric motor or an onboard engine, depending on the type of truck being used. The pump typically has two intake ports – one for supplying pressurized liquid from the tank and another for returning unused material.

The second component is the filter. This element prevents contamination from entering the tank or being pumped out into the environment. It typically consists of several layers of fine mesh screens that block contaminants while allowing clean liquids to pass through.

The third component is the hoses and fittings. These elements are used to connect various components in the wet line system together, allowing them to function correctly and without leakage. Hoses are typically made out of rubber or plastic, while fittings are made out of metal.

The fourth component is the control valve. This device regulates how much liquid can flow through the system by controlling pressure levels in different parts of it. It also helps maintain a constant flow rate regardless of any changes in pressure levels.


In conclusion, a wet line kit on a semi truck contains four essential components – hydraulic pump, filter, hoses and fittings, and control valve – which must all be properly maintained for optimal performance when transporting liquid cargo like oil and fuel. Without these components working together in harmony, it would be impossible for trucks to safely transport large amounts of liquids over long distances.

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Stephen Dunn