Function:

Marine sounding pipe caps are primarily used as sealing devices for sounding tubes. They keep the tube opening sealed under normal conditions; during measurements, the threaded cover is unscrewed, and a sounding rod is inserted to read the liquid level. They directly affect the liquid’s containment within the tank, preventing oil and gas leaks and the entry of foreign objects.

System:

A shipboard sounding system is a marine system used to measure the liquid level in ship compartments and liquid tanks. Its piping system is sealed via copper caps to ensure a closed-loop design. The lower end of the system’s piping must be positioned at the lowest point of the ship’s hold to ensure measurement accuracy; straight piping is preferred, and where bends are necessary, the angle of curvature must not exceed 25°. Pipe surface treatment varies by tank type: galvanized for water tanks and acid-washed for oil tanks. During measurement operations, the copper cap seal must be opened, and the sounding rod must be inserted vertically into the sounding pipe to the tank bottom; the liquid depth within the tank is then calculated based on the position of the moisture mark on the sounding rod upon retrieval.