Experimental studies of a ferrofluid ring in a valve mode

•Use of ferrofluid ring as in magnetic fluid seals as a valve.•Opening of the valve involves the formation of a channel in the liquid ring.•Valve without mechanical parts.•Valve that opens quickly and has features similar to a check valve. In this paper, a novel ferrofluid valve is proposed. The structure is free of mechanical moving parts and is based on a ferrofluid ring. The valve opening is created by a small leakage channel in the ferrofluid ring. The control of the valve is achieved through a magnetic field produced by an electromagnet. This type of valve can operate in a fast-opening mode and can also have characteristics similar to a check valve. It closes itself when the upstream and downstream pressure differential is below a critical value. The aim of the research is to determine the basic flow characteristics and the value of the current in the electromagnet at which the valve opens. The measured pressure/flow response was found to be linear up to the maximum pressure of 25 kPa and the flow rate of 0.87 L/min for all four different ferrofluids used in these experiments. The degree of valve opening was not higher than 2.5%. The overall analysis of the data shows that, in general, ferrofluids of high magnetization values and low viscosity are the preferred choice for the valve application.