Resurrecting old topic--short center tubes

[ekpolk]

I guess what it boils down to for me is the fact that there are plenty of other outstanding choices that do have a full length tube. I can have one of those, and not have to worry about whether the unsupported media might collapse. Of course, there is still the matter of full tube collapse, as shown above. . .

 

[kanling]

Center tube could collapse from too much pressure on it, which might occur when there aren't enough holes in the center tube for the required flow.

That's why this short center tube is kind of ridiculous. If the element is fine with a 1/2" section unsupported, why can't I have center tube supports every half inch instead of tiny holes in the rest of it. As is, I get (theoretically) poorer flow through the center-tubed part of the element and a (theoretical) spot for element collapse in the open section.

They might as well provide an e-core type of cage, with wide open spaces for the entire element. If I am taking a higher risk of element-blowthrough, I might as well get the best flow restriction over the entire element.

 

[Filter guy]

It can be crushed by hand..Done it myself plenty of times.

The core that has a straight lock seam like the one in the picture is the easiest to collapse by using your hand.

If you see a "spiral" core, those are harder to collapse with your hand. Or in some case darn near impossible depending on your hand strenght. Spiral lock cores are more prevalent in heavy duty truck engine filters.

Purolator can handle their own responces as to their testing on any "short" center tubes.

However, the basic element and center tube collapse spec for an automotive car filter is generally 90psid. The straight lock seam core passes that. Your grip exceeds 90psid..

The spiral lock cores generally collapses at 150psid or more.

If you take your filter off, look down the center area. As long as it is in tact, the filter did not "collapse".

If it not, then it has collapsed. During a collapse you have had a major pressure spike in which the by-pass valve could not open quick enough to handle the pressure. The more the pressure the more it could look like the one in Dave's hand above. Rarely, extremely rare, is it the filters fault. But the lab will need to see the filter in tact to determine.

 

[Big O Dave]

I guess I ought to get out all my filters and see which center tubes have a straight "lock" seam and which have spiral seams... whaddaya think?

 

[D$]

Sounds good to me Big O Dave!

Straight CT's tend to collapse a lot easier than spiral CT's. If you look, I bet most racing and heavy duty filters will have spiral CT's for sure. Most others, ie. 3387, 8A and so on will have a straight CT. If you think about it, spiral seems like it would be harder to make, so thats probably why most are straight. Don't have any idea about cost.

 

[Beaker74]

What exactly are we looking at in the top picture from Big O Dave? Is that a center tube that collapsed while in use or just proof that it can be crushed by hand?

 

[Jonny Z]

Sorry to dig this old one up...

Just tossed on a PL14477 on my Camry. Before I installed it, I shook it and something was moving inside. Turns out the short center tube is not secured to either of the end cap. I used the filter anyway, but it sure does not make me feel warm and fuzzy inside.

What do you guys think? Does this pose an issue?

 

[Drew99GT]

I doubt it. Run it the full interval, take it off and cut it open. Look at the bright side of the short center tube: less restriction.