How to Change a Separator Filter

Posted by ICS on Mar 29th 2018

So often, I get told by customers that they want to learn how to change a separator themselves. We have received multiple requests on the website for a “How to” on it as well. We decided to create a couple of videos that show how to change a basket type separator element on a rotary screw air compressor.

filter change

 Please note that we strongly advise that you be qualified by the manufacturer of the equipment before you perform work on it. Besides the links to the videos, I have also included some quick notes from each section. If you are changing a separator for the first time, watch the videos. The notes are meant to be quick reminders only. Don’t short yourself!

Part One- Remove all Piping and Tubing from the Separator Lid (CLICK HERE FOR THE VIDEO- PART ONE)

First and foremost, BE SAFE! Follow all appropriate lock out and tag out (LOTO) procedures. Remember that there is electrical tags as well as tagging out the isolation valves. Where the proper personal protective equipment (PPE) too!

Use the proper tools, and be safe. Remember to verify that there is no compressed air in any of the lines that you are removing. Carefully remove all of the lines on top of the sump lid.

Part Two- Remove the Separator Lid and the Separator Basket Filter (CLICK HERE FOR THE VIDEO- PART TWO)


If necessary, mark the lid and the sump so that you will remember the orientation when you put it back together. Ensure that you use the proper size wrenches. When you remove the lid, give a careful inspection of the seating surfaces as well as the filter and in to the sump.

Please note that with the sump open, it will be aery easy to accidentally drop foreign objects into the system. Be careful!

Part Three- Prepping the Work Site Before Installing the Filter (CLICK HERE FOR THE VIDEO- PART THREE)

We want to make sure that the contact surface on the lid and on the housing are clean. We want to apply anti-seize to both surfaces as well as to the bolts. We want to verify that the bolts and holes are clean.

Part Four- Installing the New Separator Filter and the Lid (CLICK HERE FOR THE VIDEO- PART FOUR)

Let’s do one more inspection before we carefully set the filter in place. Verify that the staples are in both sides if there are gaskets. Ensure that the bolt holes all line up.

When putting the lid back on, make sure that you are not overexerting yourself. Use a buddy, and/ or some rigging to carefully set the lid in place. Be careful not to pinch the gaskets or O-rings. Please note that on some units, the discharge pipe needs to be set in place at this point, otherwise, you will not be able to get it back on! Start all of the separator lid bolts. You should be able to run them down with your fingers until they touch the shoulder. If not, consider re-cleaning the bolts and holes.

Part Five- Reconnecting all of the Piping, Tubing, and the Scavenge Line (CLICK HERE FOR THE VIDEO- PART FIVE)

Be careful when reconnecting the scavenge line. It is very easy to puncture the filter, or not have it not touching the base of the separator filter at all. Both of these scenarios are wrong. I usually like to replace the scavenge line and the check valve (or orifice) when I replace the separator. Either way, install carefully, and tighten down carefully as well.

Reattach all of the piping and fittings. Make sure to use the proper fittings, and also that you back up your fittings with a second wrench. Follow mechanical best practices at all times.

Part Six- Reenergizing, Testing Your Work, and Running the Compressor (CLICK HERE FOR THE VIDEO- PART SIX)

After you remove all of your LOTO, carefully and slowly allow compressed air back into the pipe. This should allow air from the minimum pressure check valve all the way out of the unit. Verify that there are no leaks between the package discharge and the minimum pressure check valve. This is a good time to slowly remove the oil fill cap. If there is any air coming out of the cap, then their might be an issue with the minimum pressure check valve sealing off.

At this point, run the compressor for about 30 seconds and then shut it down. This will allow you to check for leaks as well as allow you to check the oil level. If there are any issues whatsoever, completely de-energize the unit. Reinstall your LOTO. Go back over your work, and find where you made your mistake. Otherwise, put the compressor back on line.

Thank you very much for coming to our website. I really hope that we were able to help you out. Please reach out to us HERE if we can help you any further. No matter what, do not try to change the separator filter, if there is any chance at all of you having to be unsafe. There is nothing in on your air compressor that is worth risking your safety.