Inline Silencer: Applications

TBS, CGS, refineries, petrochemicals, power plants, food industries, and other industries

In a gas flow path where a severe pressure drop occurs (such as regulators or valves with high-pressure drop), the sound level is about 100 decibels. This gas flow silencer is located downstream of the regulator or valve to reduce downstream sound and the environment. This silencer is designed using specialized calculation code. The acoustic performance of its components has been tested in a laboratory. This silencer is installed in the gas pressure-reducing station and reduces the noise by 15 to 21 decibels.

Properties of Inline Silencer

Fluid movement in gas and air transmission lines usually makes noise. This noise is produced in control valves, connections between lines, or sections that have cross-sectional changes. For example, the output from high-pressure compressors, pressure relief valves, gas movement inside the turbine, diversion in the branches, and also pressure drop in pressure relief valves can be mentioned.

For all these cases, a suitable inline silencer can be designed and installed in the flow path. Noise generated in stations (TBS) is related to the pressure drop created in the regulator. The silencer, after being placed after the regulator, controls the disturbances and sound.

The silencer usually has a pressure drop, But the regulator automatically compensates for this pressure drop; Because the regulator pressure sensor is after the silencer. The inline silencer can be installed after all pressure relief valves or control valves that make noise. The pressure drop in the silencer must be within acceptable limits and must not cause the regulator to malfunction. The silencers made by Sanat Prozheh Toos Company are passive types. In this type of silencer, both sound reflection and absorption cause the sound to be reduced. The two pieces of diffuser and cartridge in the silencer change the frequency of the sound and reduce it. These components are mounted inside the body of the silencer and are arranged in such a way as to have optimal acoustic performance.


Silencer function simulation

The gas pressure reducing station silencer is designed using specialized calculation code and some of its components have been tested in laboratory environments. Silencer design in specialized calculation code is based on the maximum acoustic gain; So it has the least negative impact on the mechanical performance and process of the equipment.

Body Design

The silencer body is designed for open or closed environmental conditions and temperature range of -30 to +60 degrees Celsius, the design method is based on the design standard. The choice of material used in the silencer is ASME according to the working conditions.

Audio frequency spectrum before and after installation

Sanat Prozheh Toos Company has done several researches in the field of silencers performance. The diagrams below show two examples of sound measurement results, before and after the silencer is installed.

In the above diagram, the amount of sound at different frequencies is plotted at the TBS pressure reducing stations before and after the silencer is installed. As can be seen, the volume of TBS sound level appears mostly in the frequencies of 1000 to 4000 Hz; That is the critical frequencies at the pressure reducing stations are in this range.

The line with circular markers corresponds to the station without silencer, which is at a higher level. As shown in the figure, with the installation of the silencer, the amount of sound is reduced to lower levels (line with square indicator). According to the diagram, it is clear that the silencer performed well in the critical frequency range and was able to cut the peak of the diagram. In this silencer sample, which was tested in Mashhad, the amount of sound was reduced by 21 decibels.

The next point in the silencer's performance is related to the flow rate changes and the amount of silencer noise reduction. In this experiment, the amount of sound at different flow rates before and after the silencer is installed is plotted, which can be seen in the diagram opposite. According to this diagram, it can be seen that with increasing flow, the silencer performance has not changed and still has an effective noise reduction.




Dimensional specifications of silencers

In the table below, the dimensional specifications of a number of silencers produced by Sanat Prozheh Toos Company are listed. The silencers mentioned in this table are widely used in Iran. It should be noted that the silencer in other dimensions can be made according to customer needs and orders.


Pressure drop in the silencer

The pressure drop in the silencers of TBS stations is compensated by the regulator itself due to the installation of the regulator sensor after the silencer. Sanat Prozheh Toos Company, by testing different silencer structures, has also reached models with lower pressure drop, which have larger dimensions and higher costs.

Product warranty

Silencers of Sanat Prozheh Toos Company have a warranty of up to 2 years and after-sales service is provided for up to 10 years. The noise reduction of the silencer is 15-20 decibels, which is the reason for the difference in different cases related to the structure and different dimensions of gas stations. In case of any defect or decrease in the performance of the silencer in terms of sound during the 2-year warranty, the desired problem will be solved free of charge by Sanat Prozheh Toos Company. During the after-sales service period, the company is obliged to provide only the consumer part of the silencer, namely the cartridge and other parts, at the request of the consumer.

Contact Us


Tel :051-35425513 ,  051-35425514

Fax: 051-35425513

Postal Code: 9185176935


Address :  Km12, Mashhad-Quchan Highway, Mashhad, IR Iran

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