Water separator effectiveness

[NT5224]

Hi folks, 

 

I just splashed out on an inline water separator for my  refuelling handpump.

 

The separator is the standard filter and bowl type with a tap on the bottom. It is rated to 10 Microns.

 

My question. Is 10 microns enough to filter avgas safely? I know some state-of-the-art CR diesels now  require much finer filtration, but a 1940s designed Lycoming?

 

I pump out of  44 gallon drums.

 

Cheers

 

Alan

 

[skippydiesel]

No idea as to what level of filtration you might need however I have two (x2) unused, still in box, Ryco Z980's (check with Ryco for specification) you can have for the price of one $30, plus delivery at your cost.

[Thruster88]

10 microns is plenty. Your aircraft most likely has a fuel strainer with stainless mesh rather than a filter. The idea being small contaminants pass thru rather than blocking the supply.  

[NT5224]

Thanks Thruster

 

Obviously the Lycoming has its own filter which (im guessing) is finer.

 

But refuelling out of drums through the wet season (drums are  theoretically under shelter) I want to be sure I'm not sucking in moisture... Hence the water separator. Of course I fuel drain as well.

 

 

[Thruster88]

The drum pump paper filter will not let water thru. Easy to keep an eye on the bowl while pumping.

 

The type of fuel strainer/ filter fitted to your aircraft will depend on what the builder used. My RV has a common Cessna type. There is a small strainer in the Inlet of most carburetors used by Lycoming. It can be overlooked during maintenance,  ask your LAME at the next annual.  

[skippydiesel]

You all seem to be getting hung up on the particulate filtration when the most likely contaminate , from partially empty, drums is water.

 

NT is right "on the money" wanting to prevent this contaminate from entering his air craft fuel system - why challenge the aircrafts filtration, if you can prevent water from entering in the first instance?

 

NT you are probably already know the following:

 

Water, mainly from water vapour condensing inside a partially empty drum, is the most likely source of water contamination.

 

Tilt the full drum, you are going to be taking fuel from, to create a "sump" away from the pick up tube/spike.

 

Let the drum contents settle for few hours (24 would be good) before starting to remove fuel - this will allow for any dispersed water droplets to descend  & collect in the sump you have created.

 

Best to use all the fuel, from a freshly opened drum, within a very short period, as it is the empty space above the fuel where water vapour will condense out over time (mainly night day cycles)

 

Try not to agitate contents when removing fuel - sloshing/swirling in the drum may disperse water droplets through the fuel, increasing the chance of picking it up with the outgoing fuel.

 

Do not try to get all the fuel out of the drum, as again this is when water is most likely to be drawn out with the fuel. If you want to use all the fuel - use the last few litres in the mower or some other land based engine, that wont cause a catastrophe if it stops.

 

 

About water separating filters:

 

I am no expert but it seems to me that a long, vertically mounted, filter casing is likely to have a better chance of separating water from fuel, than a short dumpy one (both are available). 

 

Probably the best water separators use a combination of centrifugal swirl, vanes and containment chamber (usually where the sight bowl is) and a sump tap (to remove any build up of water)

 

The filter part may help, a little, its main job is to remove solids eg dust/insects/paint flakes /etc.

 

[facthunter]

Letting fuel settle and then  draining from various low points in the system in the right sequence is the usual way of getting rid of  water in fuel . Moisture will condense in the tanks moreso if they are left part full in areas of humidity. Paper type filters can fail when they get a lot of water through them and you certainly don't want a blockage. I would filter all contents from a drum once the seal has been broken prior to it being available to you but strictly speaking an aviation fuel such as avtur or avgas is only "certified" for use from a new sealed drum. What you leave is not supposed to be used in a certified aircraft.. Nothing to stop you putting it into a second plane though if it's concurrent with your refuelling.. It's an anti tamper process and each drum has a release number. This process ensures you are GETTING what you should be. With Mogas no such process is in place. Nev

[kgwilson]

You could use the tilt and wait method for most of the fuel and then for the last 10 or 20 litres put it through a large Mr Funnel. That will filter all of the water out.