Fitting large hose to small barb

[Akka]

A friend has a problem with his head intake water hose: The fitting on the head is 1" but the barb on the seacock is 3/4". I suggested he slip a piece of 3/4" ID hose onto the barb, put 1" hose over the outside of that, and then clamp it down tight. He said, "Below the waterline? Is that fix ABS or ABYC approved?"

Does anybody have an answer to that?

[David M]

Below the waterline?....absolutely not. Tell him to cough up the big money for an adapter and do it correctly. Don't Mickey Mouse around with below the waterline plumbing that has the potential of sinking the boat if it fails.

Chances are there is a NPT pipe thread (tapered thread) on the head that can be changed out from a 3/4 barb to a 1 inch barb. That would be the cleanest way of doing it. The less elegant way would be to find a 3/4 barb to 1 inch barb adapter.

Do not go down to Home Depot and buy brass...it will corrode away before you know it. You want silicon bronze, bronze or some sort of non-brittle plastic. Silicon bronze would be best if you can find it.

Use 3M 4200 and not Teflon tape to seal the threads.

Looks like this...


or this...

[Target9000]

Regardless of ABS or ABYC standards... Its a bad idea to clamp over doubled hoses like that. I second David's suggestions.

[sanibel sailor]

Originally Posted by David M

Below the waterline?....absolutely not.

Unless you don't mind sinking!

[Cheechako]

cant he just replace the fitting on the seacock?

[delmarrey]

One can always go with bronze thread to hose reducers with a coupler between. A good bronze hose to hose reducer is hard to find. Personally as a Machinist I'd make my own.

But yeah! Changing the seacock fitting would be the simplest and go with a larger hose.

[David M]

Originally Posted by Cheechako

cant he just replace the fitting on the seacock?

He could put a 1 inch adapter on the seacock at the thru-hull. That would work as well.

[delmarrey]

Originally Posted by David M

He could put a one inch adapter on the seacock at the thru-hull, but then he would need to buy a length of one inch hose. I was just trying to save him the trouble and put the adapter at the head inlet.

Can he change the fitting at the head?

[motion30]

[QUOTE=David M;1200760]Below the waterline?....absolutely not. Tell him to cough up the big money for an adapter and do it correctly. Don't Mickey Mouse around with below the waterline plumbing that has the potential of sinking the boat if it fails.

Chances are there is a NPT pipe thread (tapered thread) on the head that can be changed out from a 3/4 barb to a 1 inch barb. That would be the cleanest way of doing it. The less elegant way would be to find a 3/4 barb to 1 inch barb adapter.

Do not go down to Home Depot and buy brass...it will corrode away before you know it. You want silicon bronze, bronze oUr some sort of non-brittle plastic. Silicon bronze would be best if you can find it.

Use 3M 4200 and not Teflon tape to seal the thread
I am curious as to why you favor 4200 over teflon or regular pipe dope

[s/v Jedi]

I wonder if this is a discharge of the head?

[Bash]

Originally Posted by delmarrey

Can he change the fitting at the head?

That's the way I'd try doing it--put the adapter there rather than at the seacock.

[perchance]

3/4"nipple on the seacock 3/4" x 1" reducing coupling and a 1" barb.