250 LBS plus the weight of the tank
Modern ones weigh about 80 pounds
yes and when it breaks your water heater will leak when the steel tank rust.
10,771.2 gallons with a weight of 89,724 pounds NOT including the tank
No, an expansion tank is not required.
Put it in a tank with water. Then total weight of tank + water + stingray, then take out stingray and weigh tank + water. The difference is the weight of the stingray.
expansion tank
Condensation Or the tank rusted out
The number of Kilowatts needed will vary according to the stock tank heater itself and how much use it receives.
yes
Circulation
Water expands when it is heated, this expansion increases the pressure. The bladder tank absorbs the extra pressure, protecting the hot water heater.
The part that generates heat... depending if it is a gas / electric heater
Personally I would not, as the cold water could thermo-shock the heater. And if you have a glass-lined tank, it will crack it and shorten the life of the tank. I would follow the manufacturer's instructions.