# A Self-Powered Density-Based Device for Automatic Mixed-Oil Cutting in Field Pipelines

## TL;DR

A self-powered device detects oil mixtures in pipelines using gravity, enabling automatic separation without external power.

## Contribution

A novel self-powered, gravity-based device for automatic mixed-oil interface detection and cutting in remote pipelines is introduced.

## Key findings

- The device achieves a 10 kg/m³ resolution for density changes using a float-based mechanism.
- Switching times range from 61 to 395 seconds for density differences between 760 and 835 kg/m³.
- The design supports blending ratios of 20–90% and includes a vent to mitigate gas effects.

## Abstract

Efficient oil transportation in field-deployed mobile pipelines is critical, but mixed-oil zones at interfaces reduce quality and increase waste, necessitating effective interface detection and cutting. Existing online densitometers, such as vibrating tube or high-accuracy magnetic suspension types, typically require external power, limiting their use in remote or emergency/temporary field operations. A self-powered device is presented that leverages gravitational force variations acting on a float to detect density changes and trigger automatic cutting. Validated with gasoline, diesel, kerosene, and water, it achieves a 10 kg/m3 resolution, deemed sufficient for functional batch separation in its target application, with switching times of 61–395 s for density differences (760–835 kg/m3). It supports 20–90% blending ratios, with a vent mitigating gas effects. The modular, robust, self-powered design suits emergency operations, offering a practical alternative to powered systems. Future work targets improved resolution and environmental testing.