Chem_processengineering

Why suction line diameter is bigger than discharge line diameter?

Choked flow and cavitation Cavitation occurs when the pressure drops below the vapour pressure of the fluid but then recovers above the vapour pressure as it exits the valve. This pressure recovery results in the collapse or implosion of vapour bubbles that have formed, leading to significant noise emission and erosion of the valve trim. For flashing, the downstream pressure remains at or below the vapour pressure so a mixture of liquid and vapour travel downstream of the valve. This can result in vibration due to the imbalance between the liquid and vapour phases and can lead to erosion from jet droplet impact. Choked flow in liquid occurs when enough vapour has formed within the valve where no further increase in flow rate can be achieved by increasing the differential pressure. This condition is usually avoided as cavitation intensity in the valve will be severe.