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SurfLung
Master Diver
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Joined: Sat Jan 01, 2011 2:03 pm
First Name: Eben
Location: Alexandria, MN
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Lawrence Factor Filters

Tue Feb 07, 2017 12:14 pm

Lawrence Factor Filters
- I used re-packable filters the first year with my RIX compressor. And when I checked the indicator strip on filter #1, it was light blue. I repacked the filters the second year anyway but it was always on the back of my mind that I might not be using fresh enough filter media and indicator strip. So last year, I ordered brand new Pre-Packed Lawrence Factor filters. I use three:
#1 and #2 are all 13X Molecular Sieve for Drying Air
#3 is 3-Part with 13X Molecular Sieve, Hopcalite, and Activated Carbon. It Removes: H2O, CO, Hydrocarbons, Oil, Taste & Odor, Particles
Image
- The pre-packs are about $30 apiece thru Filtertech... So roughly $100 to replace the set.
Image
- (Above) These are filters 3, 2, and 1 after removal just recently. Air travels thru them from 1-3 (right to left above)... #1 being the first filter and #3 the last filter. You can see the #1 indicator strip has lost it's bright blue color... So, the set is just reaching it's "Used Up" condition and it's time to replace them.

Removing Lawrence Factor Filters - The Lawrence factor filters fit my filter tubes perfectly and seal with their own O-Ring. I lubed the O-Ring with high pressure breathing air grease before inserting. BUT, the ends of the filter tubes only have one grasping hole and I could NOT pull them out with the usual tool. So, I hooked up a scuba tank to the inlet and used air pressure to pop the filters out. After watching the first one go shooting across the floor, I held a sock over each of the other filter tubes and that caught the shooting filters like a catchers mitt! :)
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

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antique diver
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Re: Lawrence Factor Filters

Tue Feb 07, 2017 12:46 pm

I am a little embarrassed that I did not check on availability of those filter cartridges when I sent you the filter system! Especially since I am in the breathing air business and often use Lawrence Factor cartridges myself. :oops:

Most filter suppliers recommend changing all the cartridges at once, and typically at least annually... but with multiple filter systems, I have been known to just replace the first cartridge when the subsequent ones look as perfect as yours in the photo, with bright blue strip and no discoloration of the media. On the next change time I go ahead and change them all because the media can lose some effectiveness due to time, and not just due to volume and condition of the air passed through them. I keep a close visual watch on condition of my filter cartridges, and that has worked well for me for many years, having been validated by my air test results. Saves a few $ here and there, but not always has the blessing of filter cartridge manufacturers.

BTW, your filter extraction technique sounds fun. How far can you shoot one? :lol:
The older I get the better I was.

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SurfLung
Master Diver
Posts: 1763
Joined: Sat Jan 01, 2011 2:03 pm
First Name: Eben
Location: Alexandria, MN
Contact: Website

Re: Lawrence Factor Filters

Tue Feb 07, 2017 2:54 pm

antique diver wrote:...media can lose some effectiveness due to time, and not just due to volume and condition of the air passed through them... :

- That's exactly what I was concerned with. I hadn't stored my re-pack media very well.

- Thanks for the advice on this... I re-read the Lawrence Factor instructions and the indicator strip goes from blue to pink to white. So, my light blue #1 wasn't totally shot yet. I'm thinking next time I should shift the #2 to #1 and put a new one in #2 position.
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

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antique diver
Master Diver
Posts: 2210
Joined: Sun Dec 10, 2006 12:50 pm
First Name: Bill
Location: North-Central Texas

Re: Lawrence Factor Filters

Tue Feb 07, 2017 11:38 pm

SurfLung wrote:
antique diver wrote:...media can lose some effectiveness due to time, and not just due to volume and condition of the air passed through them... :

- That's exactly what I was concerned with. I hadn't stored my re-pack media very well.

- Thanks for the advice on this... I re-read the Lawrence Factor instructions and the indicator strip goes from blue to pink to white. So, my light blue #1 wasn't totally shot yet. I'm thinking next time I should shift the #2 to #1 and put a new one in #2 position.
Shifting the cartridges as you mentioned is considered the best way to go. Good call.

I can't do that with some of the fire department equipment since many have the second cartridge with electronics at the top end. It shuts down the compressor at a given moisture level. The two cartridges aren't interchangeable. I used to have a trailered 15 cfm compressor with three tall filter towers, and replaced filters on it just like you described. Now both my compressors just have single filters.
The older I get the better I was.

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SurfLung
Master Diver
Posts: 1763
Joined: Sat Jan 01, 2011 2:03 pm
First Name: Eben
Location: Alexandria, MN
Contact: Website

Re: Lawrence Factor Filters

Mon Feb 26, 2018 10:58 am

Year 2 Filter Results
Filters012018.jpg
- I changed my compressor filters last weekend and I can see they are a bit more used up than when I changed them last year. Notice the first 13X sieve is completely pink and the second one has just begun to become a lighter shade of blue. (Deep blue is new and un-used).
- I think this is about what I want... I don't want to find them all used up because that would mean they're aren't absorbing moisture anymore.
- One Bad Thing: The new replacement for the shorter multi-filter (13X, Hopcalite, and Carbon) was about an 1/8th of an inch too long. When I installed it in the filter tube, the screw on cap got real tight before it was completely closed. So, I took the filter back out and compared the length with the old one... Sure enough the new one was a little too long. Fortunately the overlength portion is just like an extension... There's no filter components in it. So, I just sawed off 1/8th inch and then it fit fine. Hopefully next year the new one will be the right length! (followup: I contacted Filtertech about this and they handled it promptly and responsibly... I have no complaints)
Filters022018.jpg
- I did all of the scheduled lube service a week ago and now the changing of the filters puts my compressor in the full ready state for this upcoming Summer dive season. I'm going to do one other thing (I think) to assure optimum moisture separation... I'm going to rebuild the back pressure valve with the handy dandy back pressure re-build kit from August Industries. AntiqueDiver sent me the instructions earlier and I think that will be a worthwhile project! https://www.augustindustries.com/back-p ... .asp?bc=no
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SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

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