Steel Tank

[John]

To be quite honest I hadn't met this. Can you quote the reference for this particular requirement? There isn't any mention in the other references I have sourced.

[Rick]

I have not worked out these bunded plastic tanks. To me it seems its the outer one that will take all the ware & tare, so will likely fail first, but you won't ever find that out till the inner one fails.

Rick

[Steve Firth]

Or get a stud mounted anode which uses a through-tank fixing. Drill a small hole, usually 8 or 10 mm throught he tank and push the stud on the anode through the tank, fix with two nuts and shakeproof washers to the outside. Anodes nead annual inspection and replacing every year to every five years depending on actual wastage of the anode.

Cheapest place to get them is a ships chandler. About £15 a pop. The biggest UK supplier is M G Duff.

And no, I'm not making that up.

[Steve Firth]

Heh, that tank has gone up to £100.

[Aidan]

Good one, hadn't thought of that, noted for future reference. The rate of erosion of the anode depends on the surface area of the steel it's protecting and the acidity of the water. The little ones supplied for water heaters would probably last a few months. The ones I've seen used on steel water tanks were the about the volume of a football and probably weighed 40 lbs.

[John]

200 Gallons is a pretty small tank. "Standard" sizes are 250 gallon 2ftW x 5ftL x 4ftH or 300gallon 2ft x 6ft x 4ft.

Possibly because of a preference for do it in a day swap jobs.

I wouldn't like to quote a price as this can vary wildly in different parts of the country but you need to work on a concrete base which can support the weight of the tank, masonary walls either block or brick with a render lining and an epoxy paint type proofing coat. The volume of the bund should be such that it can hold a minimum of 110% of the contents of the tank and this may need to take account of any piers within the bund to support the tank. The 110% is to take allowance for accumulated rain (NO drain valve is allowed as someone will surely leave it open The OFTEC standard books show outline plans for suitable constructions based on a concrete base about 150mm thick. If you are in a position to do the work yourself (this is a d-i-y group after all) the material costs should be minimal based on sand and gravel, concrete blocks, rendering sand, cement, and epoxy paint. I'd be surprised if materials for a bund for a 300 gallon tank including base and piers came to more than £150. plus whatever you pay yourself? A single skin steel tank from a supplier in Hull would be IRO £140 collected. a double skin plastic tank would be around £700.

[Peter Stockdale]

Thanks for that , John . There seems to be differing opinon on the best course of action. I am now currently exploring the regs. to see if I can go unbunded using a smaller tank.

Pete

[bigcat]

Probably cheaper to use a steel sacrificial anode and connect to a wall wart, or possibly even mains via a high enough impedance. A reasonable lump of steel should last long time. I dont know offhand how much current is needed, but we're talking microamps/milliamps, so nothing noticeable. Might cost a penny a decade or something.

NT