It is used in heat pumps type systems such as central, unit and room air conditioners to convert the refrigeration systems and the heating systems by switching the flows way of Stable operate under low pressure difference, and it has low pressure dropping and internal leakage The electromagnetic coil is make of thermosetting water resistance, and excellent insulation Excellent sealing high energy efficiency, light weight, good vibrations resistance More energy-saving, low temperature rise, low noise and good anti-vibrations