PERFORMING CALCULATIONS

Calculating the observed flow from one outlet is pretty straight forward but working the Hazen-Williams formula can be a bit intimidating. Then there is the additional variant which involves a different formula basis for low pressure hydrants. There are all sorts of pricey programs and calculators that one can purchase. In 1984 we addressed the problem using a simple but extremely durable and low cost portable computer known as the Tandy Model-100. These tough workhorses are still in service and have never seen the shop.

Reconditioned Model-100s are still available. They can be obtained, complete with a basic "shareware" hydrant calculation program for under $300.00 from the Club-100 User Group. For more information about our use of the Model-100, please click here.

RECORD KEEPING

In order for test data to be meaningful, records have to be complete and kept in order. Practical and complete test forms are handy tools with which to encourage complete gathering of important data. They should be filled out completely while on-site to ensure the information's validity. Here is the test sheet we use: We input the information into our data base, then send the flow test sheets to the water district for their records. (In locations where the water agency does not maintain permanent records, the fire agency should keep the test documents on all public hydrants.)