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Andair gascolator in wing root?
- Thread starter 9erDriver
- Start date
Still building, but others who have Andair gascolators in the wingroot post that you can service them if the fuel tanks are less than half full. That's my plan.
I put a mini shut-off valve ( from Summit Racing) immediately upstream of each Andair gascolator. Safety wired in the open position.
Bevan
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Things to consider
Not to start a debate on the pros and cons of gascolators but what you are proposing makes no sense.
The purpose of a gascolator is to collect water and contaminants and should be installed in the lowest point of the fuel system.
By installing it in the wing root, you are effectively mounting it approx 4 inches above the lowest point in the system and right next to your fuel tank drains.
These drains are installed at the lowest point in the tank and collect/drain water and contaminants if any.
Mounting a gascolator in the wing root space is counter productive in more than one way. It is a tight space where elbows and sharp turns in the fuel line are needed to connect the in- and outlets of the gascolator. Such an installation on the suction side of the fuel system may contribute to future issues like vapor lock etc. Adding a shut off valve for serviceability is yet another couple of fittings that need space.
Not sure what your engine configuration will look like (carbureted or fuel injected). Consider an inline filter instead of a gascolator, there is simply no good place or good reason to install a gascolator on a low wing aircraft.
Not to start a debate on the pros and cons of gascolators but what you are proposing makes no sense.
The purpose of a gascolator is to collect water and contaminants and should be installed in the lowest point of the fuel system.
By installing it in the wing root, you are effectively mounting it approx 4 inches above the lowest point in the system and right next to your fuel tank drains.
These drains are installed at the lowest point in the tank and collect/drain water and contaminants if any.
Mounting a gascolator in the wing root space is counter productive in more than one way. It is a tight space where elbows and sharp turns in the fuel line are needed to connect the in- and outlets of the gascolator. Such an installation on the suction side of the fuel system may contribute to future issues like vapor lock etc. Adding a shut off valve for serviceability is yet another couple of fittings that need space.
Not sure what your engine configuration will look like (carbureted or fuel injected). Consider an inline filter instead of a gascolator, there is simply no good place or good reason to install a gascolator on a low wing aircraft.
rv7charlie
Well Known Member
What Ernst said.
Though I'm sure that Andair appreciates your business....
Though I'm sure that Andair appreciates your business....
We've plumbed quite a few wing root filter systems-
Tom
Tom
Wing Root Gascolator S-bend
Tom made my wing root flex lines from the tank to the gascolator. I made the hard lines from the gascolator onwards. The tough one was working out how to make the 90 degree S-bend as the line goes back through the fuselage side. I developed a method by making the outboard bend first using the normal procedure, then making the inboard bend by starting the bend at the 90 degree position and holding the assembly (lightly) in a wood jawed vice. This gives you something to push the tube against whilst you make the second half of the S-bend, per the photo below. I also had to place join in the line in front of the spar carrythrough, as there are just too many bends in everything to feed the line through otherwise.
Regarding whether to use gascolators or filters, it is like everything in this game, a personal choice. I wanted one filter for each tank, I did not want a fuel filter in the cockpit (for obvious reasons) nor did I want a gascolator on the firewall (for heatsoak reasons) and I wanted it easy to service, so this is the best setup I could find that met these criteria. My gascolator role is essentially used as filter, except it is easier to service than a filter, as you just have to unscrew the bowl. It has an almost identical mesh density as an inline filter, with very low pressure drop (and risk of causing vapor lock) and I've used large radius bends (i.e. no bulkhead right angle fittings) to again reduce the vapor lock risk.
Tom.
Tom made my wing root flex lines from the tank to the gascolator. I made the hard lines from the gascolator onwards. The tough one was working out how to make the 90 degree S-bend as the line goes back through the fuselage side. I developed a method by making the outboard bend first using the normal procedure, then making the inboard bend by starting the bend at the 90 degree position and holding the assembly (lightly) in a wood jawed vice. This gives you something to push the tube against whilst you make the second half of the S-bend, per the photo below. I also had to place join in the line in front of the spar carrythrough, as there are just too many bends in everything to feed the line through otherwise.
Regarding whether to use gascolators or filters, it is like everything in this game, a personal choice. I wanted one filter for each tank, I did not want a fuel filter in the cockpit (for obvious reasons) nor did I want a gascolator on the firewall (for heatsoak reasons) and I wanted it easy to service, so this is the best setup I could find that met these criteria. My gascolator role is essentially used as filter, except it is easier to service than a filter, as you just have to unscrew the bowl. It has an almost identical mesh density as an inline filter, with very low pressure drop (and risk of causing vapor lock) and I've used large radius bends (i.e. no bulkhead right angle fittings) to again reduce the vapor lock risk.
Tom.
Well, let's call the GAS375 a fuel filter instead. I didn't put these in my wing roots to be the low point for water removal, I put them there because the boost pump manufacturer recommended filtration upstream of the pump. They can still be inspected preflight to see if there is any water/contamination and remove it, but that is not their primary purpose. I investigated lots of inline fuel filters for my system, none of them met the filtration or servicing requirements.
Incidentally, Canadian regulations specifically require a "gascolator" in the system no matter high wing or low, carb or fuel injection.
1, In Canada, you will not get a final inspection pass without a gascolator installed, carbureted or injected.
2, Since I must have a gascolator, I chose the Andair because it also has a great filter (cleanable mesh) which is sufficiently fine (7O micron) for my fuel injection pump.
3, The gascolator works good in the wing root because:
A, it must be upstream of the aux boost pump and this location this also eliminates the need for the big heavy filter normally installed inside the cockpit where it is more difficult to get at for cleaning.
B, It is in a cooler environment than in the engine compartment where slow moving fuel can pick up heat.
C, The tank sumps are the lowest point in the fuel system and this is where the majority of water will collected and be removed, not at the gascolator.
D, The Andair gascolator does not need to be at the low point to collect water in a system of tubes where the fuel is constantly flowing. It collects water due to its design.
E, it is easy to make the gascolator sump-able in the wing root. In Some FWF installations, the lower cowl needs to be removed to sump the gascolator.
F. If one gascolator/filter is good, two are better. If one was to get contaminated, I can switch to the other tank complete with its own filter.
So far it works great for me. 120+hrs. YMMV
Bevan.
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