The material is not suspended in the conveying air stream in dense phase systems. Dense phase conveying occurs when the conveying air stream is between 1,200 and 2,000 feet per minute or below the minimum saltation value. Our continuous dense phase approach uses a vacuum-throttling valve that accurately maintains a constant ratio of material-to-air mass flow. As a result, the system minimizes breakage and fines – all with less energy consumption compared to other pneumatic conveying system designs. These systems are typically used with materials that are susceptible to sliding or rolling degradation where material segregation is a concern or for abrasive materials.