When choosing a 3 - 15L water filling machine, several factors should be considered. Firstly, production capacity is crucial. You need to assess your plant's production requirements and choose a machine that can meet the daily or hourly output needs. Secondly, consider the functionality of the machine. If you produce water that requires aseptic conditions, make sure the machine supports aseptic filling. Also, check if the machine can handle different bottle sizes and shapes smoothly. The automation level is another important aspect. Fully automatic machines can improve production efficiency and reduce labor costs, but they also require a higher initial investment. Semi - automatic machines may be more suitable for small - to - medium - sized plants with limited budgets. Additionally, consider the reputation and after - sales service of the manufacturer. A reliable manufacturer like ZHANGJIAGANG CITY XINMAO DRINK MACHINERY CO., LTD. can provide high - quality products and timely technical support to ensure the normal operation of the machine.