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Dry bay question


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So I have seen a butterfly type valve on the number one and four dry bays that is located on the aft wing beam. It is right next to where the refuel de fuel manifold exits the dry bay. Does anyone know it's purpose? I fly the KC130T however it is not rigged for IFR ie no pods mounted it does have the plumbing. I have been told it has something to do with IFR but I cannot find it in my pubs. Any help is appreciated.

*edit I have found it in the IPB it calls it a flapper valve.

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Hello NavyHercs

The butterfly types are three identical valves with having butter drill passage, thermal relief valve i.e one each outer dry bay for dump shutoff valve,open auto inflight or some aircraft manual SW,The First valves are uses for inflight dumping & close during ground rapid defueling is required on ground ie Dump pumps are online.One center dry bay offload valve use for quick refuel/defueling shutoff and also to isolate right side SPR to center dry line during inflight dumping to avoid fuel hazard when Aircraft is to be land emergency like gears are up stuck.The Plumbings are litter different KC-130 ,SMK1-130 C-130E,C-130B and L-382B. Different inboard dump valves.I hope you can easily under stand

Regards

Munir Abbasi Retired

Home hercules pakistan

us

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it is not a motorized butterfly valve for the fuel system it has nothing connected on either side i will try and upload a picture later. and arent all the fuel valves in the dry bay gate type valves?

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There really is no info on it that I can find. Given it is just a spring loaded flapper that opens into the dry bay from the rear beam, I would think it is some sort of atmospheric pressure relief system, but I can't find anything on it. It is visible from the flap area, correct?

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I'm gusseing here so here goes:on a rapid decent from altitude the pressure in the dry bays would be lower than outside amb.The check valve opens allowing the dry bay press. to equalize with outside press.Question is why only in bay 1 and 4?

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TinyClark 3308418-1 is the PN. if you didnt see it in my previous post. I havent found anything on it either yet.

Munir: it is not a motorized valve it nothing to do with fuel i hope i didnt confuse you when i said butterfly valve. on the other side of the dry bay it looks just like it does on the outboard. also this is aft of the rear wing beam so anti icing should have nothing to do with it either.

GVS: I thought the same thing however when you are descending wouldnt pressure want to enter the dry bay and not exit it? just like when a soda bottle is opened in flight you put the cap back on and when you land its crushed.

I was told that it is for pressure equalization my problem with that is that its one way. also what about pressure in the inboard drybays and center drybay. Someone also told me that the inboards vent through the wing attachment area and out the rainbow panels but the rainbow panels are sealed up so im left with more questions than answers. i will say this i do agree that it has to do with pressure relief somehow

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Looking at the valve,and we are seeing it from inside the bay,the flapers opening into the bay would allow the higher outside pressure to enter the bay equalizing the pressure.Another question is how is the pressure equalized on climbout to altitude?I don't remember seeing that valve on A models.Dosen't Lockeed have tech reps somewhere near you?

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that picture is from the flapwell outside of the drybay it opens to the atmosphere

I did talk to my tech rep and he said he thought it was for pressurization.

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Munirabbasi: can you explain how this would be related to anti-icing? anti-icing runs through the leading edge and the horsecollar area right? To be clearer since I may have not been with everyone. it is located in the in the flap well on the aft or rear wing beam or spar if you will. it opens outward into the flapwell and the atmosphere. it has no lines attaching to it in the drybay or in the flap well.

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http://www.lockheedmartin.com/content/dam/lockheed/data/aero/documents/global-sustainment/product-support/Service-News/V10N4.pdf

Here is the online version of the other issues... http://www.lockheedmartin.com/us/aeronautics/eoc/service-news-magazine-archive.html

"The flapper doors close any time the leading edge anti-icing system is not operating."

"Flapper valves were incorporated on new production aircraft beginning with LAC 4542 to block the passage of contaminants through the dry bays."

I knew about the Anti-icing connection but unaware (or forgot) the exhaust connection...

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Thanks So much all of you guys for helping me out! You have no idea how much this has been bugging me i completely forgot about those holes in the dry bays!

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