HEAT EXCHANGER INSPECTION METHODS - （热交换器检验方法-）.pdf

HEAT EXCHANGER INSPECTION METHODS Inspecting furnace heat exchangers is sometimes not an easy task. Each heating season someone here at HVAC-Talk will ask “ Which is the best method?” Everyone is looking for am inspection method or test equipment that will find cracks or leaks 100 percent of the time. There isn’t anyone method or tool that can be used on every style of heat exchanger. There are many areas on a heat exchanger that you can not get to for visual inspections while the heat exchanger is in the furnace. There are a variety of methods of inspecting or testing heat exchangers. Searching documents and internet sources the following is what I found on heat exchanger inspection methods and sources of information and training. Refrigeration Service Engineer’s Society’s Service Application Manual (SAM) titled Residential Gas Furnace Heat Exchanger Testing Douglas DeWerth, P.E. American Gas Association (AGA) Laboratories under SAM number 630-92 9/86. The manual outlines and explains the many test methods that are used and have been used to inspect and test heat exchangers. This manual also goes into detail about the test equipment used in the 3 step method that the AGA developed. RSES members can view the SAM minus the photographs and diagrams at . If you are not a member or want to purchase a complete copy call RSES (800)297-5660 for availability and cost. The American Gas Association developed a 3 step FURNACE HEAT EXCHANGER LEAKAGE TEST. Step 1 Visual inspection. Step 2 Burner flame deviation test. Step 3 injecting a nitrogen/methane gas mixture into the burner chamber. The heat exchanger outlet of the heat exchanger is plugged and a combustible gas detector is used to check for gas leakage on the exterior of the heat exchanger. A detailed fact sheet on the AGA test procedure is available at /NR/rdonlyres/A156C36A-9324-4978-91B4- E78DB63DAD7D/0/8612FURNHEATEXCHNGLEAKTEST.pdf