WHO WE ARE Sichuan Zhongneng Environmental Protection Technology Co., Ltd. is a high-tech enterprise focusing on scientific research, design, production, installation and technical services of "vacuum toilets". With mature technology and rich design and construction experience, ZNZK has always been at the forefront of research of China's vacuum toilet system products. ZNZK has gone on to the largest supplier of vacuum toilet in China. With 500+ installations nationally, ZNZK design engineers and project managers have been involved in a large variety of projects of different environmental and engineering challenges. Our extensive experience is not limited to design, troubleshooting and maintenance of systems. We are always there for you from the beginning to the end, from design to operation . ZNZK follows ISO9001 and ISO14001. ZNZK provides professional training programs for customers purchasing and installing vacuum toilet systems, as well as periodic inspections during installation and excellent after-sale service.