Which multi-turn valve is used on sludge lines or wastewater with high TSS?

• A. Pinch valve
• B. Gate valve
• C. Diaphragm valve
• D. Globe valve

Answer: (A)

When sludge lines or wastewater with high solids are involved, you need a valve that seals without the slurry scoring a seating surface. A pinch valve does this by pinching a flexible elastomer sleeve to close the flow path. Because the slurry never contacts a rigid valve seat or stem, there’s far less wear and clogging from gritty or fibrous material. The sleeve is the wear item and is replaceable, making maintenance practical in harsh sludge conditions. This design handles high solids and abrasive slurries well and provides reliable shutoff without the leakage issues that can plague valves with seats. In contrast, gates and globes rely on rigid seats that are easily damaged or clogged by solids, and diaphragms can be damaged by grit and may not perform as reliably with very high TSS. That’s why the pinch valve is the best choice for sludge lines with high total suspended solids.