Dosing Valve with High CIP Flow Capacity

1000:1 flow rate ratio allows for process simplification

  • schematic showing Equilibar flow control valve in dosing application, capable of high CIP flow rates
BioPharma and other sanitary process have unique requirements for control valves because of Clean-In-Place (CIP) flow requirements. This application page describes a flow control valve that can dose at low and medium flow rates while also accommodating very high CIP flow rates.

Clean-In-Place Velocity Requirements

Standard CIP requirements are to achieve 5 ft/sec of fluid velocity during the cleaning process to assure good flushing and rinsing. Sanitary processes are typically designed such that several serial components are rinsed at a time; for example, a pump, filter, transfer line, and several valves might all be part of a cleaning loop. If 2” (DN50) tubing is used, for example, then a CIP cleaning and rinsing flow rate of nearly 50 GPM is required. For many dosing, blending, and injection processes, the pumps and valves are sized too small to achieve the required pipe velocity. Typical dosing valves control well within a 20:1 or 30:1 flow rate range, making it difficult for process engineers to specify such components for both minimum dosing flow rates and maximum CIP flow rates.

CIP ByPass Valves

One typical solution is to install a CIP bypass valve around the dosing valve. Some of these bypass valves are capable of holding minimum pressure drops during the CIP process (they are effectively an engagable pressure relief valve). In other applications, such as depicted in the schematic below, diaphragm block valves are used to open up and engage a pressure relief valve or back pressure regulator. Each of these solutions adds additional complexity and testing requirements to the process design. In some cases this solution may leave small sections of the tubing without the benefit of the required flushing velocities.schematic showing CIP bypass circuit around a dosing control valve

Alternative Solution: Very Wide Range Metering Valve

The Equilibar flow control valve functions in a unique way compared to other sanitary metering valves. Instead of using a globe-style valve seat with limited flow range, it uses a direct sealing diaphragm and 1:1 dome air loading to modulate the flow rate. The interaction of the flexible diaphragm and the dozens of parallel orifices allows for a 1000:1 flow rate turn-down ratio. This exceptionally broad flow range allows the process engineer to specify a single valve to control dosing and blending flow rates while also opening up during the Clean-In-Place process to facilitate robust process flushing.schematic showing Equilibar flow control valve in dosing application, capable of high CIP flow rates

 

Learn more about how the Equilibar dosing control valve works.

Contact an Equilibar engineer to discuss your flow control application in more detail.


NOTE: This sanitary flow control valve is an adaptation of Equilibar’s established back pressure regulator product line. It is not right for every application. It has has three primary requirements: a) a flow sensor must be present in the dosing system, b) a closed loop PID loop is required to pilot the valve, and c) the upstream process pressure must be relatively stable.

Learn how Equilibar back pressure valves work

dosing control valve for sanitary process with electronic pressure regulator

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