Vetus Flexible Water Tank

[Brent Headberg]

The aluminum water tank in my 1990 33.5 finally gave in to corrosion, there wasn't a bonding strap to the tank and the welds finally split. I have just removed it and purchased a Vetus flexible water tank as a replacement ($95 vs. $350 for plastic). The bladder comes shipped from the factory with a 5/8" supply and 1-1/2" filler connection. I have 2 questions:1. Will the 5/8" supply fitting work with it mounted on top of the bladder?2. Does a bladder need to be vented?I am going to install this bladder under the v-berth and secure it to the old fiberglass tabs that use to hold down the top of the old aluminum tank. I cut the tabs along the edge of the old tank, so there's a short tab still attached to the side of the hull on both sides. This will be a temporary water tank until I can have a custom plastic tank made to fit the space under the v-berth. I'm not sure how many gallons the old aluminum tank held, but I would guess around 40 gal. The new Vetus flexible bladder holds 42 gallons.If anyone has any input, I'd appreciate it.Brent HeadbergS/V Elena Luahttp://www.elenalua.homestead.com

 

[Richard]

No and No

Brent, I recently replaced the water bladder in my Hunter. It's recommended that the 1 1/2" fill hose be on top and the 5/8" outlet hose be positioned at the bottom. Theoretically, by placing the outlet hose at the bottom any sediment which might accumulate will be pumped out. But the main reason for placing the outlet at the lowest point of gravity is so that you will pump water, not air. That brings us to your second question. No, a flexible water bladder doesn't have to be vented because it collapses as water is pumped out, thus avoiding a vacuum. However, most water systems are not perfectly air tight. And any air which leaks into it will rise to the top, which is why you don't want to place outlet tube there. I hope this has helped and good luck.Richard BaldwinS/V Weezie B

 

[Peggie Hall/Head Mistress]

Fittings...

1.5" is the standard size for the fill, but the smaller 5/8" fitting on the top isn't a supply fitting, it's a vent. Supply fitting on a water tank is 1/2"...plus it has to be at the bottom of the tank. As for whether a water tank has to be vented, some bladders do, some don't. It depends upon whether it's made to collapse enough as water is drawn out. Apparently yours is.Don't give up on a reasonably priced rigid plastic tank yet. Check Ronco Plastics (link below) ...top quality, more than 400 shapes and sizes...and prices are VERY reasonable.

 

[Steve Dion]

I don't like these tanks

Brent:I personally do not like these tanks. There are several things to consider here. First is where you are going to mount the tank. In theory, they should be mounted in a compartment so the tank is supported. The surface should be smooth, if it is not you need to line it with some felt or foam. These tanks abrade easily and it will wear holes in the tank. They are suppose to be removed for cold winter storage (don't think you need to worry about that in West Palm).You are correct about the fitting sizes. The 5/8" line is for your pump side and IS mounted on the top of the tank. There is not a vent on these tanks, as the water is consumed, the tank will collapse. You also need to be aware of over-filling the tank. Without a vent where is the water to go.My advice is to look into a poly tank and forget this. But if you must do it to save money NOW be sure to do it properly. I would guess you will get a few years out of one of these tanks and you will be replacing it soon. It is sort of like, "pay me now or pay me later".