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Posted

This question has been discussed before, I wanted some more up to date info. My age & fitness precludes climbing a ladder with either a 10 or 20 litre container. I need to carry collapsible plastic fuel bladders (20 litres each) & refuel (Mogas 95-98) from them in generally somewhat remote locations. The aircraft is an LSA, high wing, combination of carbon & GRP. What is available in well earthed electric fuel pump or, again, well earthed manual pump. Ideally I'd like to use something like a Mr Funnel as the final stage, however a built in filter, of similar capability would be easier to use. The aircraft capacity is 110 litres, so I'm unlikely to be refilling more than 60 litres at a time, 30 litres per wing. I've looked at Facet, McNaught, Polarn, FillRite, Flo Fast & Jroc.

 

Some of these are only suitable for pumping from a 200 litre drum, some are OK for jerry cans, very few are portable in that they will fit in the small cargo area in an LSA. Many don't seem to adequately address my concerns about earthing, particularly with a plastic plane.

 

Any ideas or experience please?

 

 

Posted

"This question has been discussed before" -  it certainly has and a range of options arrived at. It's all there in the Forums "history". A factory unit will cost you an arm/leg and your first born child, be very heavy & clunky.

 

I made a cost effective  & I think efficient fueling/transfer system, using a Asian copy of a Holly petrol transfer pump. The pump itself is a vane pump (look it up) it has good lift, self priming and volume delivery (L/Min) (pressure is not a significant factor in what you are trying to achieve).

 

The pump itself can be purchased online from a number of suppliers - mine cost me $70 but I have seen them for less & more. The pump is a genuine petrol transfer pump fully sealed against arking/flash

 

The variose "bits" to make it useful for pumping out of a jerry can probably took the overall cost to a bit under $100. 

 

The picture below is the Mk1 variation - since this I have replaced the suction hose with a rigid  black poly pipe "riser" & deleted the foot/one way valve & the filter.

 

The deletion of the one way valve was because the unit is self priming from a 20L jerry can and thein line  filter went because I use a filter (not a Mr Filter) funnel so no point in using two filters.

 

The substitution of the poly pipe riser (comes threred) for the suction hose was to make the unit hands free/self standing particularly when I am using 20 l collapsible bladders when away from home. It has also had the added benefit of increasing flow rate.

 

The three electrical leads are:

 

Anderson plug power supply from under instrument panel in aircraft

 

Switch for on /off

 

Ground with "alligator clamp" for connecting to aircraft earth point

 

Leads must be long enough to facilitate your particular situation.

 

I think I have been using mine for well over 12 months and found it to be most satisfactory - no more strained muscles or spilt fuel

 

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  • Like 1
Posted

The first pump in the eBay links is only an oil, kerosene or diesel pump. It is NOT rated, nor recommended for use with petrol. Using one of these pumps to pump petrol is asking for trouble.

 

The second (battery-operated) pump in the eBay links has some pretty pathetic level of output (LPM) once you try to lift fuel any height. It is really only good for liquid transfer at approximately the same level as the pump.

 

Neither is there any indication this battery-operated pump is safe for use with petrol. There certainly is no mention by the seller that it is compatible for use with petrol.

 

For a pump to be used for pumping petrol, it must be made of materials (including seals) that are 100% petrol-resistant, and the electrics must be fully sealed against any fumes getting into the motor area.

 

As most Chinese pumps use low-quality seals, I would not be using this pump to pump petrol, either.

 

The pump in the link below is compatible with petrol, alcohol and methanol fuels, and it pumps 8.3 LPM, and only draws 4 amps.

 

It appears to be very similar to Skippys pump, but I couldn't be sure what the difference is.

 

https://www.scintex.com.au/collections/12v-pumps/products/high-flow-fuel-pump

 

 

Posted
How does your vane pump handle suction?

 

Well it's almost instant self priming at the hight of a jerry can (about .5 m) so it does what I want - other "suction" (vacuum) applications I would have no idea

 

 

Posted

Photos of the latest & last, modifications of my 12 volt portable refueling pump.

 

Powered from, always live, Anderson plug secured below instrument panel. This plug also doubles as my easy battery charge/jump access.

 

Black poly fittings from local irrigation shop - one riser with female thread one end and reducer nipple to connect to pump. Length to suit jerry can or fuel bladder. Polly fitting unscrews for a more compact system to fly away.

 

Have never tested "lift hight" but in theory a vane pump, being positive displacement, should have no difficulty lifting several metres, with little additional power requirement.

 

I have made up removable  "plugs" for the delivery & suction pipe to prevent dust/insect contamination when not in use.

 

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  • Like 2
Posted

Skippy, how do you determine when a tank is full, and when/how to shut off the pump? Splash from overflow (along with vapour fumes), poses the greatest risk of fire.

 

You need to ensure there is not the slightest possibility of any sparking in the electrics and connections - how do you manage this? (after seeing a basic toggle switch, which is probably not rated as spark-proof).

 

Anderson plugs are not spark proof, and I can envision that accidental disconnection of the Anderson plug whilst fueling (such as tripping over or stepping on a cable), presents a real ignition-source problem.

 

Personally, I would prefer to see a power connection that is spark-protected, and unable to be accidentally disconnected with just a jerk - such as a twist-lock design connection with a rubber boot.

 

I've had a petrol fire caused by shorting of battery terminals when a metal article was accidentally dropped onto a battery terminal, causing arcing.

 

So, I'm fully aware of how easily fire can start, and how you must ensure that even the slightest possibility of creating an ignition source is countered, when there's open petrol containers, or petrol fumes about.

 

 

Posted

Hi Onetrack - NON OF MY home made FUEL TRANSFER SYSTEM is certified or rated in any way. YOU USE IT AT YOUR OWN RISK. 

 

Okay having got that out of the way I will give you my view:

 

Potential Spark Generators

 

Jerry can (I use plastic ones from Bunnings Aerospace) should alway be in contact with/on ground to minimise static build up.

 

System earthed to aircraft ground point - if an alligator clip can transmit sufficient current to charge a battery, surely it can provide an effective connection to reduce the chance of a spark - low risk

 

The pump itself - not rated but a copy of a well respected unit (Holly) that has been used in the automotive environment for a squillion years - so pretty safe.

 

The switch - automotive style - fully encased but should be held in the hand opposite to the one holding the delivery hose - so switch ls well  away from fumes in "clean" air very low risk of ignition.

 

Delivery hose should be held well into funnel or fuel tank  - unlikely spark generator but if occured fuel oxygen/air ratio  too high in fuel/low in O2 - will not support combustion.

 

Anderson plug - connected/disconnected befor/after fueling never during -  inside cockpit well away from fuel - accidental disconnect unlikely, if sufficient cable used for application (ie cable should never be tight) - low risk

 

On the example you gave - my battery is "buried" behind the instrument panel - nil risk of spark being caused by inadvertent connection of terminals. In your situation (??) why did the positive terminal not have a protective cover ?

 

Your concern about the Anderson plug coming out, are reasonable but if you dont use enough cable or are down right clumsy/unlucky not even a screw in plug is going to prevent damage to the cable which may in turn cause a spark.

 

As for determining full fuel - I guess it's a sight/sound thing - the pump stops delivering fuel the instant it is turned off (so no flow on). I also use a piece of old towel (nice & absorbent) to catch any minor spills - dont like petrol staines on my paint work.

 

To sum up - Yes my home made system probably has a higher risk of fire generation - we all must make these assessment for ourselves. In my case the risk with the alternative/what I used to do, lifting 20 L cans to the hight necessary to transfer fuel, of serious skeletal/muscular damage,  of dermatitis and fire from spilt fuel,  caused by my aged muscles shaking with the effort, is significantly higher (in fact a given).

 

 

  • Like 1
Posted

Looks to me to be a good setup. The only thing you might like to consider is using an aluminium suction side tube instead of plastic - less chance of spark production. If you are using a recognized fuel hose (ASTM - something) that should have enough conductivity to prevent static build up. Assuming your aircraft battery is earthed to the airframe and the pump frame is also earthed to negative, then you shouldn’t have a spark generating issue - except that poly pipe.

 

If your switch breaks the positive wire, then everything stays connected after switch is off as long as you remove hose from tank before removing the Anderson plug.

 

 

Posted
Looks to me to be a good setup. The only thing you might like to consider is using an aluminium suction side tube instead of plastic - less chance of spark production. If you are using a recognized fuel hose (ASTM - something) that should have enough conductivity to prevent static build up. Assuming your aircraft battery is earthed to the airframe and the pump frame is also earthed to negative, then you shouldn’t have a spark generating issue - except that poly pipe.

 

If your switch breaks the positive wire, then everything stays connected after switch is off as long as you remove hose from tank before removing the Anderson plug.

 

Hi Walrus - All true & good advice .

 

The poly pipe "riser:  is readily available in a range of lengths & diameters, comes  threaded, there are lots of matching plumbing fittings, it is robust (won't crack/bend/squash or corrode)  and last but not least, its relativly cheap (as am I). 

 

In my installation, the poly pipe is pretty well completely within the fuel container and the little that is above is still in a fuel rich atmosphere, so a spark unlikely to cause ignition.

 

Will have to double check but I am fairly sure the switch "brakes" the positive connection - this would be my normal practice in most 12 V wiring.

 

The fuel hose is 1/2 in Gates fuel hose. Length should be determined by individual application.

 

Fueling my aircraft is now a "doddle" - I have a custom modified funnel with internal filter, (not a Mr Funnel)  so all my fuel is filtered as it goes into the tank - its taken quite a while but the filter medium is coming close to needing replacement amazing what it catches.

 

 

  • Like 1
Posted

Thanks for all the input, some innovative ideas. I've decided to go with a commercial product, www.flofast.com.au. Hand operated, high volume pump. Different length intake legs available, pump disassembles into small components. I've found it difficult to source reels of static earthing straps, commercial ones range $800-1500 that I've found, I'll have to make some up.

 

As I have a 'plastic' plane I'm really concerned with static, so I'm going to connect hanger (or similar) to engine, engine to pump (it has a earth point on it), pump to fuel tank inlet.

 

I'll post on how it works, or not, in the new year.

 

 

  • Like 1
Posted

Hi Peter - All good.

 

Tried to get some info on the product you have decided on - computer must be on the go slow, so unable to get performance , weight etc.

 

One point - this type of pump in a jerry can or bladder will probably require both hands - one to steddy/ one to turn the handle - you will have to come up with a way to secure the delivery hose to the aircraft fill point or grow a third arm/hand.

 

 

  • Like 1
  • Agree 1
Posted

The USA site contains more info than the Oz site, go to www.flofast.com.

 

The original design was for the racing car world.

 

The delivery hose is fitted with a clamp that allegedly holds the delivery pipe in position.

 

The pump fits into a container, that electrically bonds the pump to the container. I'm hoping that I can mod the pump, if needed, to change the input pipe to a flex pipe for pumping out of flexible bladders.

 

When I get to use it, I'll let the world know if it works or not.

 

Thanks for sharing your ideas Skippy,

 

Peter

 

 

  • Like 1
Posted

Great!

 

Ref the fueling from bladder - I found it much easier to have a rigid pipe. My Mk1 variation was a fuel suction/delivery hose (see first pic). In the final modification its rigid suction poly pipe. I found it easy to rest the bladder against my leg with the rigid pipe holding the pump in place leaving one hand for filler hose and one for the on/of switch.

 

 

Posted

Hi,

 

I did occur to me that a rigid intake pipe might work better on a bladder. The company can supply a range of different length intake pipes, all can be fitted with a decent filter at the bottom.

 

It's a trade off, as you've mentioned. Keeping the pipe in the tank, supporting the bladder & winding the pump, all at the same time.

 

I'll report back when I've tried it out in the various configurations.

 

My next issue is trying to find some decent static charge discharge cable reels, the price of these is shocking. I'm thinking of exploring the use of electric fencing reels, the wire & tape wind out reels that horse owners use for temporary fencing. I'll have to look into their electrical properties, they may have much too high resistance.

 

If you happen to know of a supplier, I'd appreciate a lead,

 

regards,

 

Peter

 

 

Posted

This is a topic I have never really thaight about. I dont actually know what makes a conductor good for static - I assume that static is high voltage low current, I may be wrong. I also assume nearly any good quality electrical cable (automotive) will do as a static conductor. My single static line pump to aircraft common earth/ground point is just a length of 12 volt automotive wire. I have no connection from aircraft to ground eg frame of hanger. I have always assumed that if the pump & aircraft have a common earth and the fuel containe is left on the ground the chances of a static spark is very low - could all be wrong ?

 

You seem to be looking for a very long length of flexible conductor - if you want electric fence "wire"  you best bet is the nearest agricultural merchandising outlet. Electric fence wire comes in several configurations - there is a thin & a thick string like product  and then there are at least two tape types again a narrow tape & a broad ribbon like one. The conductor is usually multiple strands of, what to me looks like, thin stainless steel but may actually be something else. Electric fence "wire" is designed to conduct high voltahe/low current over long distances to give the receiving creature a good but sub lethal zap.

 

 

Posted

Skippy,

 

I'm relying on my RAAF training of 50 years ago for my static design.

 

Your tank may be sitting on the ground, the aircraft is on rubber tyres. Just because something is sitting on the ground, doesn't mean it's at the same electrical potential as something nearby.

 

A hangar or other building frame may not be providing you with a good earth. Best to get an electrical ground stake, about 3 meters long, made of copper, driven into the wettest patch of ground around your hanger. (Most commercial static earthing systems specify a maximum resistance between the aircraft fuel tank earth point & final earth point as no more than 10 ohms).

 

From there a 2mm or so, galvanised or SS multi strand wire, fitted with a strong clamp is run to your exhaust pipe. The line to the aircraft may have a Y fitting on it so that the second arm of the Y is clamped to the discharge tank & pump. If you don't have a Y type, a second wire is clamped  to the exhaust, the other end to the discharge vessel & pump.

 

Finally a third wire is clamped to the discharge vessel /pump & clamped to an earthing tag at the fuel filler on the aircraft.

 

If you really want to complete the job, the refueller wears a wrist strap connected to any of the points being used.

 

I haven't seen any LSA type aircraft that have earthing tags at the tank fill holes, so the best you can do in those circumstance is to ensure the filling hose is touching the neck of the tank before you start filling. You can buy filler hose that is constructed with some carbon in it, so that it has some degree of conductivity.

 

If you wonder why I'm a lot anal about static, ask your local Rural Fire Brigade to run a community demo. Pour a 20 litre can of petrol on the ground & ignite, don't be standing any closer than 50 metres when they do it!

 

An initial setup of fencing wire or building construction wire may do the job, however the constant movement will eventually cause issues. I think you'll find commercial fuelling setups, such as at airports, have to run a series of tests on the static earthing setup every six months.

 

You'll remember that my aircraft is a 'plastic' plane, so there is little likelihood of an electrical earth connection between the exhaust pipe & the tank filling point, even more reason to be careful.

 

I'm still searching for a commercial retractable reel setup at a reasonable price, when I find one (if I do) I'll let you know.

 

Please feel free to  poke holes in my thinking!

 

Peter

 

 

Posted

Wow! I have been flying for about 25 years and other than attaching a single earth clip/cable to the designated point on the aircraft, I have somehow missed all of this. Oh! and bye the way my own  aircraft is also a largely plastic fantastic.

 

On the alternative retractable reel  - certainly electric fence reels would do the job but they are much larger (I should think designed to carry 100 + metres) than anything I have seen for aircraft .

 

 

Posted

Peter, I do think you're being excessively anal about the risk of static spark igniting fuel. I know it can happen - but how many aircraft are on record, as having been burnt as a result of a static-induced fire, in the last 50 years?

 

Not any more than a very low single number, I'll wager. I reckon you probably stand a much higher chance of being hit by lightning whilst refuelling.

 

Now, I know that fuel companies, aircraft refuellers, and the military, take static discharge when refuelling, very seriously. But they have millions and multiple millions of dollars of assets at risk when refuelling.

 

They believe in ensuring any risk is reduced to as close to zero as possible.

 

But the average manual (or home-made electric pump) refueller of a light aircraft is at greater risk from fuel spill caused by tank overflow, couplings detachment, or petrol fumes coming into contact with an ignition source, than the risk from static spark igniting fuel. 

 

Static buildup on your body is caused by clothing and upholstery rubbing across each other. Synthetic fibres are notorious for creating static buildup and releasing as a "ZAP" when you touch the body of the machine, and the ground.

 

My missus' Toyota Camry is one of the worst machines I have ever encountered for static buildup, it zaps you with a ferocious zap every single time you get out, and you place your hand on the door frame.

 

I've even fitted a permanent static body strap - but this does precisely nothing to counter the static zap as you climb out - thus proving that static straps are not necessarily the answer to static buildup.

 

The static buildup from the Camry is generated on my body by sliding across the seat to get out, and then released when I touch the car door.

 

Obviously, I'm a shorter path to the ground, than the static body strap is (which is located near the rear axle).

 

I've never yet set fire to the Camry, but in theory, it should be at great risk during refuelling operations. Yet millions of vehicles are refuelled daily (without refuelling static straps being attached), and the number of vehicle refuelling fires barely registers on the records. What about the people refuelling petrol-powered fibreglass boats with inbuilt tanks, in service stations? Never seen a single one of them connect a static strap yet, when they refuel.

 

I see no reason why an aircraft should pose any greater risk than a road vehicle in the case of potential fire from static.

 

If there is a fuel fire when refuelling, the cause is generally a reason other than static. Smoking, fumes entering areas where there are gas appliance flames, unsealed electric motors, etc.

 

Even despite the dire warnings against mobile phone use near bowsers, they appear to have caused no recorded fires.

 

It's the perception that a fire may result from radio wave energy from a phone near a bowser, that drives the oil companys to be anal about mobile phone use at bowsers.

 

The commercial refuelling operations involve power sources (electric motors, engines driving pumps) that all offer a potential and increased likelihood of an ignition source, rather than just fuel-movement static alone.

 

But if you really want to go to the commercial/military level of static protection, the following website provides a wide range of equipment for refuelling and refuelling protection.

 

Page 52 of the catalogue lists several anti-static cables and clamps that may satisfy your need for 100% static protection.

 

https://www.liquipvictoria.com.au/liquipvictoria.com.au/pdfs/liquip-aviation-parts-catalogue.pdf

 

 

Posted
My missus' Toyota Camry is one of the worst machines I have ever encountered for static buildup, it zaps you with a ferocious zap every single time you get out, and you place your hand on the door frame.

 

Onetrack , try holding onto the bodywork of the car (roof panel) as you exit before you put your feet on the ground. This seems to keep you grounded to the car and prevents discharge after you exit when you close the car door.

 

Worked for me on an old Magna we had, I would have to kick the door shut so I wouldn't get zapped!

 

 

  • Like 1
  • Agree 1
Posted
Peter, I do think you're being excessively anal about the risk of static spark igniting fuel..............................................................................................................................................................................................................................................................................................................................................................................................................................................

 

Page 52 of the catalogue lists several anti-static cables and clamps that may satisfy your need for 100% static protection.

 

https://www.liquipvictoria.com.au/liquipvictoria.com.au/pdfs/liquip-aviation-parts-catalogue.pdf

 

You sound like an exceedingly well "grounded" individual . Thank you for your very well constructed comments on this topic.

 

 

Posted

onetrack, thanks for your thoughts. I think it could be argued that car static straps don't work precisely because they are not truly grounded. Just as a post in a hanger is unlikely to represent true ground, a car static strap touching the ground is very unlikely to be truly grounded. Which is why you get zapped, your body is doing a better job of discharging the static built up than the strap.

 

Your comment about mobile phones I agree with. The RF output of a mobile phone is miniscule, the potential energy in a static discharge is hugh by comparison. The fuel companies are covering their asses with their insurers.

 

I'm over zealous because I have been very close to an aircraft oxygen refilling incident, where the rules were short cut, blew the nose off the aircraft & killed someone.

 

The link you provided to liquip victoria was really useful. I hadn't contacted them, they turned out to be really responsive & helpful, unlike some others. Must be the onset of Xmas when sales depts don't return calls.

 

Thanks for you contribution,

 

Peter

 

 

  • Like 1
Posted

Peter & Skippy - Thanks for the appreciation, I try to provide useful information, as well as an opinion, when a subject is being "kicked around".

 

I've found the refuelling suppliers are generally very good - in W.A., we have PAMS, and they are very reasonable as regards pricing, as well.

 

Arron - I believe the oil companies fear as regards phones is that a user might drop their phone, and thereby create a spark if it suffers damage. Still a long shot, by any measure.

 

Here's three service station videos of static fires - the first one supposedly caused by using the phone whilst refuelling.

 

As one commentator pointed out, the action of sliding a hand into a pocket in synthetic clothing, then sliding the phone out, was more likely where the large level of static electricity built up.

 

Once he touched the refuelling nozzle, it released the static buildup on his body, caused by the sliding actions, in and out of his pocket.

 

https://www.youtube.com/watch?v=P_gAsmWYe44

 

 

 

Posted

Jet fuel is a very good insulator and that means it is a great source of static electricity- much more than petrol - which is often “dirty” so conducts. Several explosions and fires have been caused by “switch loading” - filling an empty tank that had petrol in it with diesel or jet fuel. Petrol leaves an explosive vapor and the diesel provides the spark. But back on topic, to get an explosion from fuel vapor you need to have the concentration between the upper and lower explosive limits and then supply a spark of a high energy. Fuel proof phones and radios are termed “intrinsically safe” if they can’t produce a spark of sufficient energy. All you are trying to do with bonding and earthing is to get all the gear at the same potential.

 

 

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