Water fill and vent hoses

Jul 27, 2017
44
Catalina 30 5167 Texas
Our hoses from the water deck fills to the fresh water tanks along with their respective vent hoses are both likely original are almost black inside from gunk. I measured the OD of these hoses and found they were 1.25 inches for the fill hoses and .75 inches for the vent hoses. However, I failed to take into consideration the inside diameter.

By any chance does anyone happen to know the inside diameter of these hoses?

I have replaced our water pump, added an accumulator tank, and have my new water heater ready install now, so these hoses are the final bit left between our avoiding the water like the plague and being able to drink it and use it without worrying.
 
Sep 29, 2015
97
Catalina 30 2188 St. Petersburg
My boat did not come with a vent hose for the water tanks. Where are yalls located?
 
Dec 2, 1997
8,708
- - LIttle Rock
I'll start with "hoses 101:" The inside diameter (ID) is the nominal size for all hoses. And the outer diameter (OD) is the nominal size for all hose fittings. That's because wall thicknesses of hoses and fittings can create a wide difference in the outer diameters of hoses.

Now to answer your question: The standard size for all water fill hoses is 1.5" ID The standard size for all vent lines is 1/58" (ID)...water tank and fuel tank fill and vent lines are always the standard size. This is not always true of sanitation system plumbing.
these hoses are the final bit left between our avoiding the water like the plague and being able to drink it and use it without worrying.
To make sure this will always be true requires recommissioning your fresh water system annually as part of spring recommissioning.

(You'll find complete explanations if you click on the link in my signature).
 
Jul 27, 2017
44
Catalina 30 5167 Texas
lpbosch, our vents are on top of the tanks, and the hoses go into the bottom of a stanchion. I will attach a picture from when I was measuring the hoses.
measuring hoses.JPG



Thanks for the info Peggy. I have read tons of your information. You are the reason I bought a new water heater and an anode to go in it. I am still a little confused in regards to the hose size though. I used a caliper to measure the diameter of the pipe and it was 1-1/4" OD. If the standard size for fill hoses is 1-1/2" ID, then I must conclude that my hoses are not standard. But I think the information you provided gives me the answer. Thanks!
 
Dec 2, 1997
8,708
- - LIttle Rock
If it's 1.25 OD, it has to be 1" ID....which isn't the standard size for a fill hose. Neither is the clear nylon hose shown in your photo...although the fresh water plumbing can often be clear nylon hose, tank fills and vent lines are flex PVC #148 on every boat I've ever seen. So I have a strong suspicion a PO has replaced the water tank and spec'd non-standard hose sizes AND type. What's more, the hose that appears to be the vent line is running DOWN and--assuming the tank is in a settee lying against the hull-- away from the hull. If that's where it is, it should go up to a stanchion. How old is the boat? What does the writing in red on the tank say?
 
Jul 27, 2017
44
Catalina 30 5167 Texas
Thanks Peggie, the boat is a 1988. The writing on the tank says C-30, then under it says 8/10/87 (which is the production year if I remember correctly). Here is a closer look at the writing. I am happy to learn that the standard is flex PVC #148. I will surely replace this with that.

The pictures are a bit misleading in terms of where the hoses go. This tank is in the v-berth and the picture is taken from aft, so the hoses go horizontally, and then turn up towards the fill and the stanchion as soon as they 'leave' the picture.

red-writing.JPG
 
Dec 2, 1997
8,708
- - LIttle Rock
Ok...it's an OEM tank, almost certain to have been made by Ronco...they've supplied all the water and waste tanks to Catalina for at least that long. It's highly unlikely that those clear water hoses are original though...I suspect a PO replaced 'em and went as cheap as possible 'cuz clear water hose is about half the price of #148. But I'm baffled by the 1" fill...I've never seen one before--water, waste or fuel--that wasn't 1.5", but that tank fitting is obviously original and Catalina has always done some unique plumbing...for instance, they're the only production builder (US anyway) who runs vents into stanchions (took 'em 20 years to realize that's a good idea for water and fuel, but not for waste and start running holding tank vents to a thru-hull). What size is the deckfill fitting--1", or is there an "adapter" at that end to make it fit a standard 1.5" deckfill?

I just googled 1" deck fill fittings and came up empty...they're all 1.5"
 
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Jul 27, 2017
44
Catalina 30 5167 Texas
My research also discovered no 1" deck fills. I have not gotten to the underside of the deck fill yet. Hopefully I can get to it today or tomorrow. I will take some pictures of what I find. Should be interesting.
 
Jul 7, 2004
8,402
Hunter 30T Cheney, KS
Practical Sailor had an article about adding an inline filter to the vent hose to keep the crawlies from getting into the tank. It's still on my to-do list. Amazon has the Shurflo
 
Aug 13, 2012
533
Catalina 270 Ottawa
I think it has to breathe both ways. Air out when you fill the tank; air in when you use the water.
 
Jul 7, 2004
8,402
Hunter 30T Cheney, KS
I think it has to breathe both ways. Air out when you fill the tank; air in when you use the water.
I think this is correct. Otherwise you'll create a vacuum and not be able to draw freely from the tank
 
Oct 22, 2014
20,989
CAL 35 Cruiser #21 moored EVERETT WA
@Smunkey the comment by @dziedzicmj is right on. If you do not have the system neutral the air pressure you will either blow up or deflate the tank. Neither of these results is desirable.

I learned about the blocked vent tube while filling my port water tank. The water was flowing in from the hose till the pressure had built up, then there was what sounded like a burp and a geyser of water shot back out of the fill tube drenching me and a couple of friends standing on the dock. Fortunately you don't cry over spilt water.
 
Dec 2, 1997
8,708
- - LIttle Rock
I have not gotten to the underside of the deck fill yet. Hopefully I can get to it today or tomorrow. I will take some pictures of what I find. Should be interesting.
Start by looking at the outside of the deck fill...the size will be obvious. Remove the cap and measure the threaded ID of the fitting (or the OD of the threaded part of the cap)... .on a 1.5" fill, it's most likely 1.25". The hose barb will be 1.5" OD...to fit a 1.5" hose.
 
Jul 27, 2017
44
Catalina 30 5167 Texas
I braved the chilly 26 degree wind and precipitation (that's pretty cold for Texas) to go measure. I wasn't able to get a good measurement on the top of the fill under the cap, but I could see there was no adapter or anything. Here is a picture of that:
fill-1.JPG

(you can sort of see the hole is 1", the threads on the cap seemed 2")

Anyway, since I will be replacing all associated hoses anyway, I took off the panel to access the underside of the fill, and it was in fact a 1" fill tube somehow. Here is a picture of that:
fill-2.JPG


I also grabbed a pic of the model number that was on the tank:
tank-1.JPG


as well as a close up of the elbow part that the fill hose connects to:
elbo-1.JPG


There did not appear to be any adapters on this end either, that elbow goes directly into the tank.

Now that know the sizes for certain, I can source some flex PVC #148 and make it right, or as close to right as I can. I plan to add a filter inline on the vent as well.

Thanks a bunch to everyone who pitched in!
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
Nothing wrong with a 1" fill hose. The garden hose to fill it is no more than 3/4. My 2 cents is to take the chain off that links to the cap. you'd be able to get a hose in there and not have to hold it. While you're at it, chamfer the outside of the deck fitting to make getting on the hose that much easier.
 
Dec 2, 1997
8,708
- - LIttle Rock
In 30 years, this is the first 1" deck fill I've ever seen. Now that I have, owners of older boats that have 'em will prob'ly start coming out of the woodwork!

I'd do some homework on water tank vent filters if I were you...'cuz it's important that nothing block the vent. How much maintenance is required? How often should they be cleaned or replaced? Will getting wet ruin 'em and block the vent as it does to holding tank vent filters?

My 2 cents is to take the chain off that links to the cap. you'd be able to get a hose in there and not have to hold it.
If he does, sooner or later he's guaranteed to lose the cap overboard, which will require replacing the deck fitting,,,'cuz we've already determined, 1" deck fills are no longer available, which means replacement caps aren't either. The hose will stay put if you just stick it down the hose far enough.
 
Dec 2, 1997
8,708
- - LIttle Rock
This is a system- Input-tank-and vent.
All tank "systems"--waste, water and fuel--are input, tank, vent and discharge. A"failed"/blocked vent would only allow a few gallons to be added to the tank, so unless you're paying -0- attention while filling, there shouldn't be much of a geyser...and besides, it's only water. The worst thing that SHOULD happen is water out the vent, which isn't a bad thing 'cuz it rinses out the vent line.
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
...If he does, sooner or later he's guaranteed to lose the cap overboard, which will require replacing the deck fitting,,,'cuz we've already determined, 1" deck fills are no longer available, which means replacement caps aren't either. The hose will stay put if you just stick it down the hose far enough.
Not so sure about that, Peggy. It's hard to tell from his picture, but if he measured the THREADED cap, he might find it the same size as 1.5-hose deck fittings. His one-inch caliper reading suggest the pipe throat is,say, 7/8? I don't think a garden hose with a metal fitting will fit in there enough to allow it to sit on it's own so the crew can go do other stuff while the tank fills. If he keeps stuffing the hose into the fill, sooner or later the chain will break- trust me on that one. My waste cap- and I'm sure others- do not have the chain because the pumpout hose has to either screw in or form a seal around the fitting. Other readers, does you waste have a chain on it? My waste cap does not even have a screw-hole for a chain. In 10 years I've not lost the waster or water caps, even with bi-weekly fills and pumpouts. It's just common sense to put the cap down on the seat, not on the deck.