Prist
03-28-2008, 06:54 PM
#31
Chief Jeppesen Updater
Joined APC: Oct 2005
Position: Executive Transport Driver
Posts: 3,080
Just to clarify it's not an oil filter bypass light, but a FUEL FILTER BYPASS issue on the Encore that would be the issue here (at least where prist is concerned).
We add prist to the tanks of our Encore about ever other fueling (or at the very least every third).
The main reason is because of its supposed anti-microbial properties. It's supposed to help keep gunk from growing in the tanks.
We add prist to the tanks of our Encore about ever other fueling (or at the very least every third).
The main reason is because of its supposed anti-microbial properties. It's supposed to help keep gunk from growing in the tanks.
03-30-2008, 12:27 AM
#32
New Hire
Joined APC: May 2007
Position: C560 (Ultra) PIC / KingAir SIC
Posts: 8
Josh - thanks for the clarification on that.
The point was - its may be a good idea to add Prist because of the possibility of the heat exchanger getting left out in the event of a specific inflight emergency (as you pointed out).
The point was - its may be a good idea to add Prist because of the possibility of the heat exchanger getting left out in the event of a specific inflight emergency (as you pointed out).
03-30-2008, 05:29 AM
#33
Chief Jeppesen Updater
Joined APC: Oct 2005
Position: Executive Transport Driver
Posts: 3,080
Originally Posted by gordo282
Josh - thanks for the clarification on that.
The point was - its may be a good idea to add Prist because of the possibility of the heat exchanger getting left out in the event of a specific inflight emergency (as you pointed out).
The point was - its may be a good idea to add Prist because of the possibility of the heat exchanger getting left out in the event of a specific inflight emergency (as you pointed out).
Aside from being foul and rather disgusting ooze, it could definitely clog fuel lines/filters.
Even with a fuel filter bypass, you should have enough time to get on the ground (pronto) without any other further incident.
03-30-2008, 06:48 AM
#34
Gets Weekends Off
Joined APC: Aug 2007
Position: Corporate Captain
Posts: 164
For the record...
Retrieved from http://www.csdinc.org/prist/faq2.html#Q2
Note the final paragraph.
Our product is certified to MIL-DTL-85470B for the chemical diethylene glycol monomethyl ether (DEGMME). The primary purpose of this chemical is to prevent freezing of water in the fuel system of aircraft. It is this property that is covered in Military and ASTM specifications. These specifications contain no biocide requirements.
Prior to 1994, Prist additive was made to MIL-I-27686(E), which specified ethylene glycol monomethyl ether (EGMME). We paid to have this product certified as a pesticide with the EPA. This allowed us to advertise the ability of Prist additive to retard growth of microbes in aviation fuels. The correct term is microbiostat, not microbiocide (-stat means it controls or retards growth, -cide means it kills microbes). With all of the new EPA requirements, it became economically prohibitive to certify the new DEGMME based additive as a pesticide.
Summarizing the above, it is widely believed that DEGMME does have a retarding effect on microbial growth, however, we no longer officially claim this property for the Prist additive.
If you truly want to add a biocide/biostat, you need to add Biobor JF.
Retrieved from http://www.csdinc.org/prist/faq2.html#Q2
Note the final paragraph.
Our product is certified to MIL-DTL-85470B for the chemical diethylene glycol monomethyl ether (DEGMME). The primary purpose of this chemical is to prevent freezing of water in the fuel system of aircraft. It is this property that is covered in Military and ASTM specifications. These specifications contain no biocide requirements.
Prior to 1994, Prist additive was made to MIL-I-27686(E), which specified ethylene glycol monomethyl ether (EGMME). We paid to have this product certified as a pesticide with the EPA. This allowed us to advertise the ability of Prist additive to retard growth of microbes in aviation fuels. The correct term is microbiostat, not microbiocide (-stat means it controls or retards growth, -cide means it kills microbes). With all of the new EPA requirements, it became economically prohibitive to certify the new DEGMME based additive as a pesticide.
Summarizing the above, it is widely believed that DEGMME does have a retarding effect on microbial growth, however, we no longer officially claim this property for the Prist additive.
If you truly want to add a biocide/biostat, you need to add Biobor JF.
Last edited by geosynchronous; 03-30-2008 at 06:53 AM.
03-30-2008, 07:41 AM
#35
Chief Jeppesen Updater
Joined APC: Oct 2005
Position: Executive Transport Driver
Posts: 3,080
Geo,
In speaking with a rep from the company that manufactures Prist at NBAA, they still hold by the arguement that it will help prevent microbial growth, however due to the cost requirements to certify it, they simply no longer advertise it as such.
At least that's my understanding. We also run Biobor through our tanks every couple of months at regular mx intervals. The only difference there is that you can't purchase biobor premixed like you can prist. (It's a mx function for us).
In speaking with a rep from the company that manufactures Prist at NBAA, they still hold by the arguement that it will help prevent microbial growth, however due to the cost requirements to certify it, they simply no longer advertise it as such.
At least that's my understanding. We also run Biobor through our tanks every couple of months at regular mx intervals. The only difference there is that you can't purchase biobor premixed like you can prist. (It's a mx function for us).
03-30-2008, 08:31 AM
#37
Gets Weekends Off
Joined APC: Aug 2007
Position: Corporate Captain
Posts: 164
That's pretty much the assertion from the Prist web site mentioned above, the MIL-Spec/ASTM formula missing one ether atom circa 1994-present does not guarantee bio-static qualities.
We are fortunate that our fuel vendor is Phillips, which has a quasi-Biobor JF formulated in to the fuel.
Another assertion or subjective argument for using Prist can be...less water = less of a growth medium= less corrosion possibilities.
I know that Bombardier likes to blame fuel additives to the problems associated with their fuel compensation probes vs. blaming the vendor who makes their parts...subject of a completely different thread...
We are fortunate that our fuel vendor is Phillips, which has a quasi-Biobor JF formulated in to the fuel.
Another assertion or subjective argument for using Prist can be...less water = less of a growth medium= less corrosion possibilities.
I know that Bombardier likes to blame fuel additives to the problems associated with their fuel compensation probes vs. blaming the vendor who makes their parts...subject of a completely different thread...
10-14-2010, 07:00 AM
#39
New Hire
Joined APC: Oct 2010
Posts: 2
Prist is no longer an anti-microbial agent
Originally Posted by Tgaug6300
Prist is also Anti-microbial agent. Therefore it helps to keep sludge from forming in the fuel systems. This is important if the airplane rarely flys. We fly our aircraft Mon-Fri, so it is not sitting for very long, so we very seldom add it. Many times it is already pre-mixed, so it is not an option.
TG
TG
The most recent data from the IATA fuel microbiology community indicates that under the very best of circumstances, DiEGME (diethylene glycol monomethyl ether) can only slow the growth of microorganisms by about 40%. Again, that's best case scenario.
Regardless of how often you operate, its important to regularly perform fuel system analysis. The test kits we recommend are from Conidia Bioscience. They are by far the most popular, accurate and easy to use. These kits are sold through Satair. Based on what you find, treat with an approved biocide.
There are only 2 biocides approved for use in aviation globally - Biobor JF and Kathon FP 1.5. Biobor JF has been the standard for many years. Its safe and easy to use. Kathon FP 1.5 is an oxidizer and is highly corrosive. I would discourage anyone from putting this product into an aircraft fuel system.
www.pristaerospace.com
www.conidia.com
www.satair.com
08-22-2012, 10:09 AM
#40
New Hire
Joined APC: Aug 2012
Posts: 1
Originally Posted by FlyerJosh
Just to clarify it's not an oil filter bypass light, but a FUEL FILTER BYPASS issue on the Encore that would be the issue here (at least where prist is concerned).
We add prist to the tanks of our Encore about ever other fueling (or at the very least every third).
The main reason is because of its supposed anti-microbial properties. It's supposed to help keep gunk from growing in the tanks.
We add prist to the tanks of our Encore about ever other fueling (or at the very least every third).
The main reason is because of its supposed anti-microbial properties. It's supposed to help keep gunk from growing in the tanks.
Thanks to years of eroneous claims by marketers of pre-blended fuels with fuel system icing inhibor, referred to by most as "Prist", DiEGME, sometimes referred to as FSII, is not a fuel biocide. Because the chemical isolates water molecule in fuel, FSII will, if used continuously partially act as a fuel "biostat", but it does not and will not kill the microbe. Microbial growth found in hydrocarbon fuels require three elements to grow and multiply; fuel for food, water to hydrate and a temperature above 70'F. Without any of the three, the bug can live dormant indefinately, but is NOT killed. Since the FSII will act to at least partially isolate the water, the microbe may be dormant or inactive, but it is not eliminated. Fuel that is treated irregularly will have little if any preventative measure against microbial contamination. Microbial activity can not only obstruct fuel flow, but if left untreated can cause major damage to an aircraft since waste from the bugs is highly corrosive. I admit to being prejudiced to Biobor JF. It was the first biocide approved for aviation and remains the most popular since it poses the least hazards to aircraft, equipment and personnel. Someone suggested that Phillips uses a "quasi-Biobor JF" additive. Let me assure you, that is not true. Phillips uses DiEGME and it is NOT a biocide.
