The Piaggio has a sink. Cool, you say! I am trying to figure out how to get water into the sink faucet.

The system is a rectangular tank with two water sections (hot/cold) with outlet connectors and an electrical plug for hot water heater. Removable bung plugs on top to put water in.

This tank slides into a fairly snug cabinet box which aligns water inlet plumbing with the outlet connectors and an electric connector.

However, the outlet connectors of the tank are simply open. Water pours out as soon as you put it in. And the inlets are just tubes which fit in these connector holes with o-rings for a bit of seal.

But I can't figure out how to get the water tank in without all the water emptying itself all over the interior of the cabinet. It takes several seconds of aligning the tank to the cabinet to get it to slide, and then slide in and plug in place. During which time the water has streamed out over everything.

Has anyone seen tanks/connectors like these before? Should there be some kind of water seal/valve on the tank that keeps the water in until it's properly connected to the fittings?

Thanks!

My guess: Remove only for cleaning, sanitation, and inspection.

Fill when already in place using a hose.

Good thought, for sure! Had the same thought. But there is no access above it to get to the bung plugs for filling. I don’t mean tight access, I mean no access!

What’s the flight manual say? Or the maintenance manual? One of them has to have a description of how it operates and instructions for servicing it. Maybe the parts manual would indicate if you are missing a piece.

Great questions, thanks for the thought. In this case, the flight manual doesn’t seem to say much about interior servicing (it says plenty about “airworthiness” servicing like tires, fluids, etc), the parts manual only shows large cabinets as complete assemblies and doesn’t break out the detail parts, and the maintenance manual describes briefly how to remove the entire vanity assembly but doesn’t mention merely filling the water tank.

Still scratching my head a bit. I’m at a bit of a loss how they expected to get water in the thing.

Some other guy explaining how he did it:

Well, I like a puzzle.
After studying the pics I see the outlets on the tank are indexed so that something will only fit into them a certain way. The connections in the back of the cabinet do not appear to have any indexing design features. So, my conclusion is you are missing a small part that attaches to the outlets by aligning with the slot-like index and the small hole. The piece that’s missing likely incorporates a check valve which is opened when the outlets mesh with the fittings in the cabinet.
Or, perhaps you lay the acft on its side, so that the tank outlets are point up, thus avoiding spillage during servicing.

Yes, good eye, I kind of think so too.

So I’m fishing around to see if anyone has seen such a valve-thingy since I can’t seem to find any reference. Possibly not unique to Piaggio.

Jon
Is the OD of the pipes connected to the plane substantially equal to the ID of the fittings on the tank? I ask b/c while I like the "missing part" theory I ask why there are O rings if there is some missing part.

RAS

Correct, ID/OD of the fittings match such that the oring provides a seal. So any missing part would need to get itself out of the way as those fittings slide together.

It looks like a speed fit coupler, John Guest makes some, and others copy the design, you seem to be missing the shut-off feature of it which closes the valve and allows for quick removal

the aircraft side looks like the standard male fitting which should just be two o-rings

https://www.grainger.com/product/2YCU5

https://www.freshwatersystems.com/produ ... y-1-4-bspt

info here

https://assets.freshwatersystems.com/im ... h9eymo.pdf

That looks about right! I suspect we have a winner!

That said… how would I get that back off? Does the fitting lever need to be actuated in order to remove it? When installed, the tank gives no access to the back side where the fittings are, the cabinetry is closely fitted.

I will confirm fitting sizes, but that looks about right. Thank you!

I was going to comment that your tank appears to have one indexing pin at the bottom, one at the top, so you wouldn't depress both levers from the same direction to remove it, that is confusing to me too

But then I remembered your airplane has a tiny wing on the nose and the engines are facing backwards, so who knows what they were thinking!

They make several versions, I included a link to the PDF, I'm not sure if yours is welded in or threaded in, but I would suspect you are missing the "moving" parts of the coupler, the valve and the gate latch, you could likely swap these parts over from a good valve, but I'd try replacing all of the valves with new ones, this isn't an area you want a leak

Italian engineering… sometimes interesting solutions.

I will figure out in more detail exactly what I’ve got vs what’s needed, now that you’ve given me the basics, thanks!

I would think someone at a Service Center would know what you’re missing and how to get it, if it’s available.