Test Method for Compressed Air System

Perform monitoring of the following parameters for consecutive three days:

1. Particle count test
2. Dew Point Temperature/ Moisture Content
3. Oil Content Measurement Test
4. Microbiological Test (Air Sampling)

AIRBORNE PARTICLE COUNT

OBJECTIVE

Determining user point’s particulate cleanliness is lying within the limit.

TEST EQUIPMENT

Air Borne Particle counter

METHODOLOGY

• Set up the particle counter in accordance with the EOP of the particle counter. Confirm the Location & Room name or sampling point, sampling time, counter model no, and volume flow rate. The calibration date/ calibration due date must be on the print screen.
• Set up the particle counter with High-Pressure Diffuser (HPD) for Measuring solid particles. To setup with a high-pressure diffuser, first set the HPD with the main supply line of the compressed air so that the main supply of compressed air will be attached to the inlet of the HPD. Now, connect the particle counter at the outlet of the diffuser with the help of a tubing system.

• Take at least 3 sampling data from each user point.
• 100 LPM capacity particle counter will be used and the sampling time will be 60 seconds.
• Record the result in Appendix.

DEW POINT TEMPERATURE/ MOISTURE CONTENT

OBJECTIVE

Determinate user point’s compressed air cleanliness for moisture content condition is lying within the limit.

TESTING EQUIPMENT

Use a water/moisture measuring instrument (dragger tube/RH Probe along with psychometric chart) to test this parameter. Ensure that the instrument is calibrated/certified/within a valid date range.

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METHODOLOGY

• Set up the dragger instrument as per the Standard Operating Procedure (SOP) of the dragger instrument for moisture content measurement.
• Set the Air pressure to 3 bar using a pressure regulator and take a sample for 2.5 minutes. Measure the moisture content and note for documentation.
• Repeat the test for moisture content another two times.
• Record the result in Appendix.

OIL CONTENT MEASUREMENT

OBJECTIVE

Determinate user point’s compressed air cleanliness for oil content condition is lying within the limit.

TESTING EQUIPMENT

• Use an oil measuring instrument (dragger tube for oil measurements) to test this parameter.
• Ensure that the equipment is calibrated/certified/ Valid Date Range.

METHODOLOGY

• Set up the dragger instrument as per the Equipment Operating Procedure (EOP) of the dragger instrument for oil content measurement.
• Set the Air pressure to 3 bar using a pressure regulator and take a sample for 5 minutes.
• Measure the oil content and note it for documentation.
• Repeat the test for moisture content another two times.
• Record the result in Appendix.

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MICROBIOLOGICAL TEST

OBJECTIVE

This test is to demonstrate that classified areas are capable to maintain viable microbial load within the acceptable limit.

MEDIA TO BE USED

Tryptone soya Agar (TSA).

Sabouraud Chloramphenicol Agar (SCA).

Tryptone Soya Broth(TSB)

Fluid Thio-glycollate Medium(FTM)

METHODOLOGY

A.  Sterility test of Compressed Air in Grade A area

• Take 1×100 ml of sterile TSB and 1×100 ml of sterile FTM for each compressed air Outlet (Sampling Point).
• Label outlet number or sampling point name and room number and date.
• Wipe the sampling point with a sterile duster soaked with filtered 70% IPA and allow it to dry.
• Open the valve of the compressed air sampling point and allow it to pass out compressed air for 2-3 minutes to come out water if any.
• Connect collecting tubes with the sampling point. Carefully remove the cap from the sterile TSB and FTM media and insert the gassing needles below the level of the liquid medium.
• Perform the sampling activity under the laminar airflow cabinet.
• Allow the compressed air to “bubble” through each medium for about 10 minutes (the air flow must be on a low setting to prevent the solution from over the top of the bottle) to collect about 1000 L volumes of compressed air.

• After sampling, carefully remove the sampling bottle and replace the cap immediately.
• Transfer this collected sample to the microbiology laboratory for incubation as per SOP for 14 days and after incubation observes the growth and keep the record in the Appendix.

B.  Microbial Count of Compressed Air by MAS-100NT Air sampler

• Wipe the sampling point with a sterile duster soaked with filtered 70% IPA and allow it to dry.
• Open the valve of the Compressed air system and allow passing out compressed air for 2-3 minutes to come out water if any. Connect collecting tubes with the sampling point, if required.
• Place the prepared TSA plate on the plate holder of the Air sampler.
• Open the lid of the plate carefully.
• Set and operate the machine according to EOP and collect the sample.
• Carry out the same procedure by using SCA plates.
• After sampling transfers the plates to the microbiology laboratory for incubation.
• Incubate the TSA plates at 30-35ºC and SCA plates at 20-25ºC for 05 days.
• The test is to be performed according to SOP.
• Record the result in an appendix.

ACCEPTANCE CRITERIA

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