Most people believe that if something costs more, it has to be better quality. In the case of generic drugs, this is not true, says Gary Buehler, Director of FDA's Office of Generic Drugs. The standards for quality are the same for brand name and generic products..uch of FDA's review of generic drugs and brand name drugs is the same, Buehler explains (See Same FDA Requirements for Brand-Name and Generic Drugs below).
Then evaluate tank water heaters on the same gph basis to determine how many gallons of storage are needed to meet this demand. While tankless water heaters do not run out of hot water, if not sized correctly, the flow rate of that water can be adversely impacted.
Volume Test This test is to determine if the water heater is supplying the correct amount of hot water. The test is based on 120 degree F. storage temperature and these amounts are approximate. Test Procedure: Do not use any hot water for two hours to ensure the accuracy of this test. Turn on the cold water at full flow using a double handle faucet and time how long it takes to fill a one-gallon jug. Calculate the flow rate as follows.