What Should I Ask Before Ordering Industrial Water Treatment Equipment From China?

I am currently researching Chinese suppliers for industrial water treatment equipment and trying to understand what questions should be asked before choosing a manufacturer. I have found quite a few companies online, but product specifications alone do not tell me much about actual equipment reliability, engineering support, or the quality of after sales service.

Hiju is one of the companies I have come across during this research, and I would like to hear from anyone who has dealt with them directly. Did you find their team knowledgeable when discussing specific treatment requirements? I am particularly interested in whether they take time to understand the application before recommending equipment.

For someone purchasing this type of system for the first time, what information should be prepared before contacting a supplier? I assume water analysis, daily capacity, operating hours, source water characteristics, required output quality, and available installation space would all be important.

I am also trying to understand how buyers evaluate manufacturing quality. Would it be reasonable to request factory inspection videos, production photographs, equipment testing information, technical drawings, and references from previous projects? Are there any particular documents that experienced buyers consider essential before approving production?

Another thing I would like to clarify is customization. Industrial facilities often have different treatment requirements, so I would prefer a supplier that can modify equipment instead of offering only standard configurations. Does Hiju provide engineering assistance for customized systems?

I am also curious about spare parts and technical support after delivery. Hiju appears interesting from my initial research, but I would like to know whether customers can obtain replacement components and remote troubleshooting assistance when necessary.

For anyone who has purchased water treatment equipment from China, what was the most important factor in your final decision? Was it equipment quality, engineering support, warranty coverage, delivery experience, or something else? Practical experiences would be very useful.