AFP inline fuel filter or gascolator?

[Bubblehead]

Thanks for the added info, Kahuna.

I checked for the fuel pump you mentioned Here is a like to one place that sells it. It looks like the one from Vans.

http://www.partsamerica.com/ProductD...tNumber=P74015

Their price is $72.99. Note that it is just the pump, not the other parts that come with it from Vans but if all you need is the pump, this might save a bunch of money.

The fuel pump system looks like it has three parts. I think the large cylinder is the pump itself. Then a smaller gold anodized part, and then a smaller still blue anodized part. Can someone fill me in on what the gold and blue parts are?

[JonJay]

Fuel Filter, pressure return valve.

[Bubblehead]

I thought the fuel filter was a separate unit. And which is which (gold, blue). By pressure return valve I assume that's a check valve?

[JonJay]

Yes, the filter is separate.

I am not sure which item is which by color as i am not at home to check, but there is a Relief Valve and a Bypass Swing Check Valve that are part of the assembly.

As with all of Vans pre-assembled parts, they are usually a pretty good value for the money. By the time you end up with the pump, valves, tubing, mount, and other supplies, plus your time to source and fiddle, you might be into this more than you think.

[Bubblehead]

I agree. I'm not trying to assemble a complete unit - I already have one working fine in my RV-8. I'm just trying to better understand the innards.

Here's a picture to help everyone's memory.

[rvermeland]

The blue part is a check valve. This keeps the high pressure fuel pump on the engine from pushing fuel back through the electric fuel pump. The gold part is a relief valve. It allow continuous flow through the pump when little on no flow is going through the firewall. The fuel just recirculates through the pump and a short amount of plumbing. The fuel filter in Van's setup is in a gold anodized cylinder nearly the size of the fuel pump. But it is not shown in your picture.

-rob

[Don at Airflow]

Originally Posted by rvermeland

The blue part is a check valve. This keeps the high pressure fuel pump on the engine from pushing fuel back through the electric fuel pump. The gold part is a relief valve. It allow continuous flow through the pump when little on no flow is going through the firewall. The fuel just recirculates through the pump and a short amount of plumbing. The fuel filter in Van's setup is in a gold anodized cylinder nearly the size of the fuel pump. But it is not shown in your picture.

-rob

If you describing the Airflow Performance pump, you need to get the correct information, which by the way, is with every pump we send to Van?s or provide with pumps that are shipped from our facility. The blue valve is the relief valve. This sets the pump out put pressure when the pump is running. Since the pump ?acts? like a positive displacement pump (it?s not really) the excess fuel that the engine is not using gets circulated back to the inlet of the pump. With out this valve the pump will generate around 125 PSI; also fuel is necessary to cool the motor so the re-circulating fuel accomplishes that. The gold valve on the assembly is a swing check valve. Its purpose is to allow free flow to the engine driven fuel pump when the boost pump is off. So when the pump is on the swing check valve closes to keep the pump output from short-circuiting back to the inlet of the pump. If you need the installation and operation manual for this pump assembly P/N 3090050 or the filter assembly P/N 1090079, contact me by email and I can send you a copy


Don

[erich weaver]

Don:

Do you have any comment regarding the previous recommendation (see post #11 on this thread) to change the filter element to a 25 micron screen?

thanks

erich

[Don at Airflow]

Originally Posted by erich weaver

Don:

Do you have any comment regarding the previous recommendation (see post #11 on this thread) to change the filter element to a 25 micron screen?

thanks

erich

I certainly don?t want to step on Kahuna?s toes, and everyone is entitled to their own opinion. We based the filtration size of the P/N 1090079 filter on flow capacity, and the partial size that would lock up the boost pump. Based on the filter area and the amount of debris that could be absorbed by this filter element and pass until it restricted the flow to a point that vapor was possible were the parameters that we used to come up with the filtration rating. Other factors were the filtration down stream in the fuel injection unit and in our case the flow divider. So when people arbitrarily install finer filters, they may get by with it if their fuel is always clean. If 25 microns is good, why not put in 5 microns to be sure. If you had unlimited filter area this would be the way to go. I don?t know what his issue was (may have been installation related that lunched the pump) but we have found that the filtration rating we designed for this filter works in 99.9% of the installations. It?s flown around the world in a Long EZ and has accumulated over thousands of hours without problems. So for what it?s worth that?s our story.

Don

[Kahuna]

Not stepping on my toes and Im glad you jumpped in. In my case for my rv-6 4 banger, I was burning up pumps ~250 hours. Pump would make strange noises for ~50 hours then stop working. I think I burnt up 3 pumps. Filter was part of the pump assembly right before the pump. At the recommendation of I cant remember who from the RV-List, I tried the 25 micron. It lasted 750 hours before I sold the plane.

With those limited data points, I put the 25 micron in my Super 8. It has been working fine for ~600 hours. Based on my data, if the 25 flows enough for the 6cyl lyco, then an even finer mesh would flow enough for the 4 cyl. I would say you would want the absolute finest mesh possible that still gives you the maximum flow needed and not a drop more, at some % of clogged up. Need to max flow with debris in there. Based on my limited experience over ther years cleaning fliters, that percentage would be less than 5% but thats a SWAG. Just my 2 cents.

Best,