Fuel strainer (fuel drain) replacements

[BlakeinAlabama]

Is there a certain fuel strainer that goes under the infs or are there a couple of styles to pick from. I am needing 2 and wanted to know what seems to work good for others.

[GAHorn]

Is there a certain fuel strainer that goes under the infs or are there a couple of styles to pick from. I am needing 2 and wanted to know what seems to work good for others.

The only strainer I know of that goes under infants are Pampers.

[Bruce Fenstermacher]

Is there a certain fuel strainer that goes under the infs or are there a couple of styles to pick from. I am needing 2 and wanted to know what seems to work good for others.

Blake, I'm sorry, I can't quite figure out what your talking about. And it's obvious George was operating at the same loss.

There are two fuel strainers (are there any in the tank pick up I don't remember?) which is the gascolator and the finger strainer in the carb.

What is an infs? Knowing this might help us.

[GAHorn]

[...fuel strainers (are there any in the tank pick up I don't remember?) .....

Yes, finger strainers exist in the tank exits.

[johneeb]

..................

What is an infs? Knowing this might help us.

maybe "in fuel system"

[BlakeinAlabama]

Sorry, I didn't proofread. I was referring to the fuel check valve under the wing.

[FredMa]

If you mean the fuel drain, no. A filter would hold contaminants in the tank. Why would you want that?

[FredMa]

I meant strainer.

[BlakeinAlabama]

The fuel drain valve that you check the fuel for water. What is the part number? There a many sizes etc.

[lowNslow]

Here is what you want for the underwing fuel drain.
http://www.aircraftspruce.com/search/se ... ?s=Cav-170

[Bruce Fenstermacher]

Karl has the right part.

Be advised however more than one 170 has had the wrong valve put into the thank with the wrong thread. Might have been done accidentally or might have been done on purpose because the threads had become buggered up. The point is replace what your take out if threads are different.

[GAHorn]

This back-and-forth/confusing discussion-thread might have been* an excellent example of why it is important to have an Illustrated Parts Catalog to specifically identify items in question. The simple picture of the item....would have resolved exactly the part in question and the fact it has no strainer....and the exact part-number (or would lead to the superceded pn.)

*(might have been...but hopefully you get the idea) if the IPC hadn't had such a poor relationship to actual practice. In this case the A and B model IPC's get it awfully-wrong, showing a short pipe (never existed in A/B models) and a "plug" which most folks have replaced with a drain-valve.

Of course, the straight-170(ragwing) IPC (which is actualy illustrated as above in the A and B IPC's) had no illustration at all.
Perhaps THIS confusing IPC situation on THIS particular part is what prompted this particular crazy thread!

The exact model aircraft needs to be properly identified.... Not all of us have (170 / 170A / 170B)(select your model) aircraft, and often the parts are not the same.

To top that off: The CAV-170 part number supplied is a SAF-AIR item number. Curtis also makes these things, as does certain other mfr's.

Then (just for bluElder) there's the matter of legality. Since Cessna only made the airplanes with ordinary pipe-plugs for drains, what is the basis of approval for installing quick-drains? (And, when that topic is exhausted...., WHY is it necessary to have an STC if one wishes to install a drain valve on the fuel selector valve?)

Ain't this fun?

[Bruce Fenstermacher]

Interesting piece of trivia. I never noticed our planes came with An AN 814-4D plug, NOT and ordinary pipe plug or a quick drain.

Then (just for bluElder) there's the matter of legality. Since Cessna only made the airplanes with ordinary pipe-plugs for drains, what is the basis of approval for installing quick-drains? (And, when that topic is exhausted...., WHY is it necessary to have an STC if one wishes to install a drain valve on the fuel selector valve?)

Ain't this fun?

OK without doing research I'll stab at the answers. (the answers are guesses and not necessarily correct until substantiated)

Since Cessna only made the airplanes with ordinary pipe-plugs for drains, what is the basis of approval for installing quick-drains?

• Since there is no AD that I can think of I'd venture to say there is a Cessna Service Bulletin which allows this.

Why is it necessary to have an STC if one wishes to install a drain valve on the fuel selector valve?

• Because the approval which is the answer for the first question did not cover the fuel valve location and any change to the fuel system would be a Major alteration requiring an approval of some sort, not necessarily an STC.

There is BTW an STC to install a quick drain in the fuel selectors of B models but no other models. A problem with this STC if you have one of the first 18 B models you have the A model fuel valve. A quick drain can still be added but it won't line up with the hole as provided in later B models. When I queried the owner of the STC wondering why he limited the STC to B models he said because they had different fuel selectors. When I pointed out 18 B models had the early valve and would be covered by his STC and therefor all the A models should or could also be included, he didn't care.

[GAHorn]

.... When I queried the owner of the STC wondering why he limited the STC to B models he said because they had different fuel selectors. When I pointed out 18 B models had the early valve and would be covered by his STC and therefor all the A models should or could also be included, he didn't care.

I'll bet he realizes that his STC isn't req'd in order to install a quick-drain...where an ordinary plug-drain exists. (And BTW, the STC-Owner/Seller supported our Assoc'n with donations of his products at the Tehachapi convention. That, and at least his packaging includes the correct drain for the intended-purpose (fuel selector drain.)

In the case of the latter, machined-alum block selector-valve, it is a 1/8" pipe plug thread. Don't overtighten or you'll crack that multi-thou$and-dollar valve.... Remember...it's only GRAVITY pressure at that point, no need for heavy-handed tightening....and never never never never use Teflon-Tape in a fuel system!

[hilltop170]

No matter what fuel tank drain is used under the wing fuel tanks, it must be thin enough so the door does not hang up on it.