Well, this stinks.
I received my big expansion tank today, but ... the top of the internal overflow tube ends ends 2.25 inches below the top of the tank.
Attachment 5728
That is two inches lower than it should be. That means that this tank only holds 33 oz before overflowing, not the advertised 45 oz. The return policy says that I pay the return postage plus a 20% re-stocking fee. Before doing that, I e-mailed Speedmaster and asked "Are all of these tanks made the same way? I would like to get a correctly made unit, but it would not do me any good to return this one if you send me another incorrect unit just like it."
I suppose that I could try to push a two-inch piece of rubber hose onto the overflow tube and it would correct the deficiency, but I should not have to do that. Dang it.
Here is my math to calculate the actual volume:
The barrel of the tank measures 10 3/4". The internal overflow tube ends 2 1/4" below the top of the tank, so the tube is 8 1/2" long. Area = pi * R squared = 3.14 * (1.5" * 1.5") = 7.07 sq in. 7.07 sq in * 8.5" = 60.1 cu in * (1 pint /28.875 cu in) = 2.08 pints. The actual volume of the tank is 2.08 pint *(16 oz/pint) = 33.28 oz, not the advertised 45 oz. The missing 2" of overflow tube = 0.49 pints, or 8 oz.