When evaluating a screw press, the most critical factor is the moisture reduction efficiency. You must verify the compression ratio and the screw diameter/pitch design, as these determine the throughput capacity. For wastewater applications, ensure the machine features clog-free self-cleaning mechanisms (like moving rings). Material construction is equally vital; look for SUS304 or SUS316 stainless steel to prevent corrosion, especially when handling acidic or abrasive sludge. Additionally, check the motor power and gear reducer brand (e.g., SEW or Nord) to ensure long-term mechanical reliability under high torque.