The small size makes it easy to handle. With its simple structure, it is also highly durable. As a relief valve to pumps, there is no noise or vibration, while operation is reliable. The balanced structure of the piston ensures there is minimal change in the emission pressure even when there is change to the back pressure. The open piping allows it to be used as a valve to prevent water from falling on the side of the equipment when the pump is stopped. Maintenance and inspection can be done by simply disassembling the top part.