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OldFrog75 · 10-06-2016, 09:26

Can someone please post a photo/schematic of how older Y-valves open/close? Was on a 10 year old beneteau with a convoluted 2 y-valve system in the line between the head and holding tank/overboard and I got confused.

peghall · 10-06-2016, 12:05

Can someone please post a photo/schematic of how older Y-valves open/close?

The same way newer ones do...a lever either moves a 'gate' or rotates an internal barrel with holes in it to open or block the outgoing flow. The handle aligns with the direction of the flow. You can find exploded drawings of y-valves on the mfrs' websites.

As for any schematic of where y-valves may be located in the plumbing, that varies so much that there is no "has to be done this way" schematic. There may or may not be a y-valve in the toilet discharge line that offers a choice of flushing into the tank or directly overboard...if there is, it can be installed before or after any vented loop (there should be one if the toilet can flush overboard)...in the tank discharge line the y-valve MUST be installed between the tank and any overboard discharge pump.

Cheechako · 10-06-2016, 12:16

Some Y valves are confusing as heck for sure. The flow isn't in the handle direction like most valves.

peghall · 10-06-2016, 12:52

Which ones? Except for those on which the handle was misaligned when it had to be replaced or the valve disassembled to clean it out, I've never seen one that wasn't.

Cheechako · 10-06-2016, 12:56

Maybe it's just me! This one always leaves me wondering:

Cheechako · 10-06-2016, 12:59

Then this one has a pointer, but the handle kinda goes with a flow possibility too... "what do dat do?" Is the flow with the pointer and one end of the handle? Which end? Or with the handle only? If so, what is the pointer for?

savoir · 10-06-2016, 13:07

Y valves usually work opposite to the "follow the handle" rule. The handle generally indicates the closed pipe but no doubt there are some exceptions. Watch Mutt and Jeff explain Jabsco valves.

https://www.youtube.com/watch?v=650_NM2THhE

OldFrog75 · 10-06-2016, 14:42

Quote:

Originally Posted by Cheechako

Some Y valves are confusing as heck for sure. The flow isn't in the handle direction like most valves.

That's my problem. "Typically" the handle points in the direction of the blocked flow which is opposite of traditional single hose binary open/close through hull fittings but I wasn't certain it's 100% of the time and if the "handle" is short then who knows unless there is an owners manual on board.

OldFrog75 · 10-06-2016, 14:46

Quote:

Originally Posted by savoir

Y valves usually work opposite to the "follow the handle" rule. The handle generally indicates the closed pipe but no doubt there are some exceptions. Watch Mutt and Jeff explain Jabsco valves.

https://www.youtube.com/watch?v=650_NM2THhE

Thanks but I already watched that...didn't help. Although the hoses are a "Y", the handle is not and older fittings don't have arrows on them.

Cheechako · 10-06-2016, 14:52

Especially confusing when you didn't install but inherited it!

OldFrog75 · 10-06-2016, 15:09

Quote:

Originally Posted by peghall

Can someone please post a photo/schematic of how older Y-valves open/close?

..in the tank discharge line the y-valve MUST be installed between the tank and any overboard discharge pump.

If I'm reading this correctly then why install a "Y" valve? Why not just a single hose open/close valve? What's the additional hose for?

I get having one "Y" valve to choose overboard vs. holding tank but the second one had me wondering.

Wish I had a picture to post.

Cheechako · 10-06-2016, 15:14

Quote:

Originally Posted by OldFrog75

If I'm reading this correctly then why install a "Y" valve? Why not just a single hose open/close valve? What's the additional hose for?

I get having one "Y" valve to choose overboard vs. holding tank but the second one had me wondering.

Wish I had a picture to post.

Yep, just a T and a seacock works.

savoir · 10-06-2016, 15:42

Quote:

Originally Posted by OldFrog75

Thanks but I already watched that...didn't help. Although the hoses are a "Y", the handle is not and older fittings don't have arrows on them.

You don't need arrows. On most Y valves the handle will be sitting above the closed valve. If you are not sure fill the bowl with a bucket of salt water. Add some food dye and pump then look over the side and in the holding tank. The dye will have to be in one of them. Use milk if you have no dye.