Purpose of our test

In order to be able to provide our clients with comple- te information, our technical division has designed and used a special test desk for the testing of com- pressed air silencers and sinterised filters which we produce.
Following ISO 9001 certification, the test phase is a very important procedure in our quality control manual, especially for new products.
We were assisted in our purchase of measuring instruments by the technical unit of ASA, Sesto S. Giovanni (MI).
The noise tests were performed in work environments where pneumatic equipment is normally used.
The purpose of our tests was to assist designers in the choice of the best compromise between carrying capacity and noise reduction.


The report is thus divided into the following:
1) flow tests
2) noise tests
3) flow diagrams
4) comparative flow diagrams


instruments description
The carrying capacity and noise tests were performed with the following instruments:

1) flowmeter asa model e5 2800
serial number 117026 max flow 16000 nl/h

2) flowmeter asa modello e5 3000
serial number 121021 max flow 125000 nl/h

3) flowmeter asa modello e5 3100
serial number 122021 max flow 240.000 nl/h

4) flowmeter asa modello e5 3100
serial number 122023 max flow 400.000 nl/h
the values scale on the flowmeters
was calibrated to a pressure of 1013 mbar

5) pressure regulator nuova insert
model with attachments of 2”

6) ferrari manometer

7) noice measurer model sl-4001
lutron model with liquid crystals display. resolution of 0,1 db and reading range:
30 – 80 dB
50 – 100 dB
80 – 130 dB


The test was performed by altering the origi- nal pressure through the pressure regulator. This took place during the open circuit, while the air flowed from the silencers.
The related pressure was measured using a manometer.
Subsequently the values of the related flow- meters were checked using the data shown on the flowmeter scale multiplied by a factor K which varies depending on the pressure pre- sent in the flowmeter at the time of its reading. The test was performed on all silencer models using the same pressure range, beginning from 1/8” to 1”, in order that we could prepare com- parative diagrams of thread sizes given that the operating conditions of each model were the same.

The carrying capacity has been calculated as follows:

K= 1,414 pressure for 1bar
K= 1,732 pressure for 2bar
K= 2,000 pressure for 3bar
K= 2,236 pressure for 4bar
K= 2,449 pressure for 5bar