Valves, Actuators & Pump Control


Controlling valve noise

October 2015 Valves, Actuators & Pump Control

Control valve noise is generated by high pressure drops across the valve and by the subsequent turbulence downstream. As a result, noise is radiated to the surrounding area by the downstream piping system. In situations where equipment damage or personal injury could be caused by a noise source, noise reduction is not only desired, it is mandatory.

A diffuser plate is a pressure reducing device that is installed downstream from a control valve. The total pressure drop needed for flow control of a flow control loop is divided between the valve and diffuser. This enables the valve to operate at a lower pressure ratio and greatly reduces the control valve noise level generated by steam, gas or vapour flow. A properly selected diffuser valve combination can result in a noise reduction of up to 40 dBA. The diffuser plate must be designed for each unique installation so that the noise levels generated by the valve and diffuser are equal.

Mitech’s locally manufactured diffuser plates are designed for use with its globe control valve on high pressure drop applications for gases and vapours. It significantly reduces the control valve noise level generated by the gas or vapour flow. The diffuser plates are installed downstream from the valve to create a back pressure. On high pressure drop gas applications, the valve size is selected to maintain the velocity at the outlet within the limit of Mach 0.33 (1/3rd of sonic). By creating a back pressure, the gas or vapour is compressed to a greater degree, and therefore a smaller valve can be selected while still keeping the velocity within acceptable limits.

Special trims are still often required inside the valve as the downstream plate is not effective at creating back pressure at low flow rates. In these conditions, the valve sees the full pressure drop. However, the velocity in the smaller valve is still acceptable due to the lower flow rate.

For more information contact Pieter Badenhorst, Mitech, +27 (0)11 927 4850, enquiries@mitech.co.za, www.mitech.co.za





Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

Protect your pump and keep it longer
July 2021, Elemental Analytics , Valves, Actuators & Pump Control
Unexpectedly losing a pump is often an expensive or even a dangerous problem in a chemical plant.

Read more...
Locally valves manufactured for tailings pipeline
June 2021 , Valves, Actuators & Pump Control
The AFS manufacturing plant in Benoni is equipped with advanced equipment and is supported by specialists who offer dependable technical support to ensure the optimum safety, efficiency and extended service life of every system.

Read more...
New flange monoblock with shut-off valve
March 2021, WIKA Instruments , Valves, Actuators & Pump Control
WIKA’s new monoblock with flange design integrates a shut-off valve to separate the process from the instrument side.

Read more...
The Stafsjö HX story – greater demand calls for action
February 2021, Valve & Automation , Valves, Actuators & Pump Control
As a knife gate valve supplier, Stafsjö supplies product solutions to realise efficiency and production goals in pulp and paper applications.

Read more...
Drives for solar-powered pump systems
February 2021, Bearing Man Group t/a BMG , Valves, Actuators & Pump Control
BMG advises on how to optimise efficiency and extend the service life of solar-powered pumping systems by selecting the correct drives.

Read more...
Optimise fermentation in alcoholic beverage manufacturing through proper valve selection
February 2021, ASCO , Valves, Actuators & Pump Control
Emerson can help select the right fluid automation products to meet all unique requirements.

Read more...
Smart positioners of the future
January 2021, SMC Corporation South Africa , Valves, Actuators & Pump Control
SMC’s new range of Smart Positioners was designed to pair perfectly with a variety of process control valves and actuators.

Read more...
Robust control valve proves itself in the construction materials industry
November 2020, Macsteel Fluid Control , Valves, Actuators & Pump Control
Ball sector valves from Schubert & Salzer excel in abrasive slurry applications.

Read more...
Check valve with redundant sealing
September 2020, WIKA Instruments , Valves, Actuators & Pump Control
The new model CV check valve from WIKA is designed for a wide range of applications in the process industry. Its sealing system reliably prevents backflow of liquid and gaseous media.

Read more...
Sustainability through packaging efficiency
August 2020, Valve & Automation , Valves, Actuators & Pump Control
There is probably no other term that has been used and interpreted in recent years in so many ways as the term ‘sustainability’. Originating from forestry, today the principle of sustainability is comprehensively ...

Read more...