Where to purchase a secondary filter tower and priority valve?

[frogman62]

Jim, What pressure are you going to be pumping into the bank? I have filters and moisture trap shown on my website which will provide Grade E breathing air. Two chambers will cost you less than the Bauer if you are going to pump less than 4000PSI if you are pumping over 4000PSI the august industries chamber is excellant and at a good cost.
Jim Shelden
sheldensportinggoods.com

 

[frogman62]

Hoosier, the accumulator you show is the same unit. I believe the cartridge (repackable or purchased) saves the cylinder from corrosion and I also use the plunger to create a better moisture trap . I drill 4 holes in the plunger which acts as a moisture diffuser and the drain system is very effective.
Jim

 

[pescador775]

ASME recommends a 4 X 1 factor for appliances such as valves, tubes, fittings, etc. The reason, it appears, is that these devices are either small in size, or large but not weight sensitive, are subject to abuse and other factors, or are made of materials which are difficult to test or verify long term health. However, there are many high pressure containers such as SCUBA tanks which are manufactured to 2.5 X 1 minimum. There are practical reasons for this such as weight, ease of manufacturing and cost. However, this latter category are made of materials for which excellent data are available for strength, durability and service life. Hydrostatic tests and inspections are mandated by DOT of approved containers made to known specifications to monitor their integrity over time.

Some materials for which cycle life (fatigue) are difficult to quantify include some stainless steels and some aluminum alloys. Hydraulic accumulators are often made of these materials. Aircraft aluminum, a typical material for accumulators, is very strong in tension and gives fantastic numbers when tested to destruction. However, this material does not hold up well to repeated pressure cycles due to its low ductility. This is one reason why a 4 X 1 factor is used, to minimize flexing when pressurized and to ensure a long life. Manufacturers probably apply this safety factor to yield which is about 12,000 psi for an ASME spec'ed aluminum vessel rated at 3000 psi.

 

[frogman62]

Hoosier, Pescador775, I agree with your comments. That is the reason I only purchase new ,unused hydraulic accumulators. I also worked for Beech Aircraft/Raytheon for 36 plus years and managed the Target Missile division in Wichita Ks for the last 12 years of my career. I am well aware of the fatigue issues with aluminum structures and accumulators. There are significant differences in the usage of these cylinders for filters vs accumulators. In the accumulator normal usage these would be subjected to a minimum of 25,000 cycles with high surge pressures ranging from 1500 to 3000psi over many years. Fatigue will become a major factor in the later work cycle of the cylinder. In a filter application they will not be subjected to surge pressure at any time and certainly will never see 25,000 pressure cycles. This would translate to filling a scuba cylinder 365 days every year for 68 years. The bigger issue is cleaning the cylinder every time chemical change occurs and disposing of the chamber if major corrosion or pitting of the stainless steel side walls occur. One of my engineers (Structural engineer for 30 plus years and a diver) also, with a quick analysis, informed me that fatigue would never be an issue.
Jim Shelden

 

[Hoosier]

I am not suspicious about your hydraulic accumulator application. This application has been used by many people. Even, Oxyhacker's book addressed DIY filtration system by using a hydraulic accumulator as I recall.

I just want to know your design in more detail. I think your filtration product is the most competitive option in the market. But, I prefer two chambers instead of one, so the first chamber is dedicated for MS and second for MS-AC.

What is a re-packable tube size, height and diameter?
How many grams of MS can be packed in your re-packable tube?

More spec. information will be great for a potential buyer.

Thanks,

 

[frogman62]

Hoosier, Lets look at both options which I have provided to a few customers,
1. The tube for a combination moisture trap and filter is 2 inches in diameter and 6 inches for chemical pack, Filling is for paint ball applications is the full 6 inches of Linde 13X - providing about 25 hours of compressor run time before a change is necessary. Oil and water penetration is about 75% visible in the chemical column.
2. The tube for breathing air is packed 3 inches of Linde 13x, compressed foam separator, 1/2 inch of Hopcalyte, compressed foam, and 2 inches of activated carbon.
3. The other option offered is using the Lawrence Factor equivalent of American Bristol 42XCAC which has less chemical quantity than my re-packable cartridge.
4. For compressors delivering 6 to 12 cfm, I recommend two chambers. The moisture trap with the same configuration as the paint ball chamber and the filter utilizing a 9 inch tube with 1 1/2 inches of Hopcalyte and the remainder filled with activated carbon. I recommend changing the moisture trap (Linde 13X) every 20 hours which is is a little on the safe side and changing the filter chamber every 50 hours. I did some air quality testing on this procedure and found that I was still getting E grade breathing air from the filter after 75 hours of run time - but the Linde 13X was changed at 20 hour intervals.
I also recommend anyone in a dive shop application to only use replacement filters from a manufacturer and change them as recommended for liability purposes.
Do you have any other questions. I appreciate the questions as they provide better answers to air quality issues and may assure future customers of air quality from my filters.
I have incorporated one other safety feature in my automatic system compressors -- an auto drain timer which dumps the moisture from the "trap" for about 10 seconds on 15 minute intervals.
Some shops desire this feature because they sometimes forget to manually operate the moisture drain during long run periods. For the individual diver who does not have a storage bank - he usually changes tanks every 15 minutes so draining is done when he changes to fill another tank.
Frogman62 Jim Shelden
sheldensportinggoods.com