7/8" hose fitting

[Sefuller]

Our boat has 7/8" heater hose from the heat exchanger to the water heater. I need to replace them as I am installing a new water heater, and I am having difficulty finding 7/8" hose barb fittings. Ideally I'd like to go from 7/8" hose to 1/2" male npt, but I could come up with other solutions if I could find any 7/8" barb connections. Anyone know of a source?

Thanks

 

[capta]

Google is your friend; 7/8" hose barb

 

[Ralph Johnstone]

I am having difficulty finding 7/8" hose barb fittings.

NOTE: hoses are measured by inside diameter (ID) not outside diameter (OD). Does this solve the problem ?

I don't think you'll have a whole lot of luck as 7/8" doesn't exist. Barbed fitting sizes (from 1/2" to 1") are 1/2", 5/8", 3/4", 1". Here's a list of NPT X hose adapters from Groco Marine:

If 7/8" barbed fittings don't exist, neither does the hose. If your hose is 7/8" OD, I would estimate the ID to be 5/8".

You don't need to go with expensive bronze fittings as brass will do fine in your treated water/glycol internal and DHW external systems.

 

[dlochner]

You don't need to go with expensive bronze fittings as brass will do fine in your treated water/glycol internal and DHW external systems.

Actually, in a potable water system avoid bronze as it may contain lead.

 

[Peggie Hall HeadMistress]

NOTE: hoses are measured by inside diameter (ID) not outside diameter (OD).

Ralph is correct. If you measure the INSIDE diameter of that hose I'm pretty sure you'll find that what you really need is a 3/4" hose. But you can double check that if you check the specs in the installation instructions that surely must have come with the new water heater.

--Peggie

 

[Mark Maulden]

Reuse the current fittings?

 

[Sefuller]

Google is your friend; 7/8" hose barb

I have spent quite a bit of time using Google and Duck Duck Go on this quest. If you are able to find an actual viable result, please forward to me.

 

[Sefuller]

Folks, I appreciate all the replies, but I have spent quite a bit of time using search engines and checking online marine chandleries as well as McMasterCarr, Grainger and many others. The Universal diesels use a heat exchanger with 7/8" hose connections. The hoses are Shields 250-0780 which is a wired heater hose with an ID of 7/8". It is hard to find but is available. I actually just went to the Toad Marine Supply website to look at the schematic of the heat exchanger to verify that it is 7/8" and stumbled across a Westerbeke nipple that goes from 7/8" hose to 3/4" NPT which I can easily adapt to the 1/2" I need. At $45 each they are a little spendy, but looks like this will solve the problem!

I am surprised others have not run into this issue, and given the scarcity of 7/8" ID hose, I am curious why Catalina Direct or whoever is making the new heat exchangers doesn't change the nipples to 3/4"? Looking at the Catalina Direct website, they have the pre-formed hose which is clearly labeled 7/8".

 

[Ralph Johnstone]

Google is your friend; 7/8" hose barb

Which goes to prove, given enough time, you can find ANYTHING on Google. I once found a perpetual motion machine !

But aside from that insanity, @Sefuller , is quite right. Shields does make a 7/8" ID hose:

The Toad Marine Supply price for the adpter reflects the rarity of this specimen.

@Sefuller congratulations on finding the correct part and best of luck with this nightmare . This is probably the most infuriating conundrum I have heard of, to date.

 

[dLj]

Sometimes I find it easier to design a custom piece to go between what exists and what is desired. If you don't have the ability to do the custom work yourself, a good machinist is good to find.

Just a thought.

dj

 

[Ralph Johnstone]

Just a thought.

More than just a thought. Sound advice in many cases ............................. after all, this IS a boat.

 

[Mark Maulden]

Call Sure Marine in Seattle