"During World War II," LeVan noted, "all cast iron pipe, whether cast iron water main or cast iron soil pipe, was statically cast as compared to centrifugally cast today. In an effort to save resources at that time, both cast iron water main and cast iron soil pipe were produced to a federal specification which called for emergency weight for water main and victory weight for soil pipe. I don't know what the new thicknesses were, but I suspect they were still very adequate. I occasionally see victory weight soil pipe still in service, as identified by the letter "V" on the hub. A building that I pass regularly in downtown Chattanooga still has victory weight main leaders exposed. I suspect there are still many other buildings in service with this weight pipe. I suspect the same is true with the water main weight."
It would be interesting to know how many other readers know of victory pipe that is still in use.
More is Not Always BetterInside the tank on low-flow water closets is a mark indicating the proper water level to which the tank should be filled. Many contractors, homeowners and even engineers believe that a better quality flush can be obtained by setting the water level above the fill mark. Their reasoning is, "The more water, the better the flush."
However, Ballanco noted, "The number one reason for a poor performing water closet is improper water level adjustment." Why is that? The answer is because today's water closets are designed for optimal flushing performance using an exact amount of water (usually 1.3 to 1.6 gpf). In many instances, additional water reduces the siphon action in the bowl and results in a poor quality flush.
Engineers questioned about "poor performing" water closets should always address the issue of water level. First, check to see that the water level is set to fill the tank to the water line indicated by the manufacturer. Second, check to see that the flapper is dropping at the point of maximum siphon. Third, check the rim jets for construction debris (today's water closets will not operate efficiently when even one or two rim jets are not operational).
Homework QuestionsHow much do you really know about plumbing engineering? To find out, see if you can answer the following homework questions given to students in the class (the answers can be found below):
- 1. What are the three types of water closets?
2. What does "dfu" stand for?
3. A bathroom group is generally assigned a dfu value of...?
4. What is the ANSI/ASME standard that regulates vitreous china fixtures?
5. Plumbing system drainage sizing is usually based on which type of flow: full, three-quarters, or half?
6. A drainage pipe pitched at 90N is referred to as what?
7. What is the minimum pitch for a 3-inch drainage pipe?
8. Roof drain strainers are required to extend how many inches above the roof deck?
- 1. Public, private and flushometer.
2. Drainage Fixture Unit.
4. ASME 112.19.2.
5. Half-full flow.
6. A stack.
7. 1/4-inch per foot.
8. 4 inches.