NCCER HVAC Level 1, Module 8 - Soldering Brazing 2023/2024 verified to pass

NCCER HVAC Level 1, Module 8 - Soldering BrazingWhat is a neutral flame? Equal parts oxygen and acetylene What is a carburizing flame? A cooler flame used for light brazing. At what PSI does Acetylene become unstable? 15 psi What do you use to light a torch? Cup Striker Why is it dangerous to use a lighter to light a torch? The flame may travel back into the lighter and cause it to explode. How far do you open the acetylene valve on the tank when brazing? 1/2 turn to a full turn What is an alloy? Any substance made up of two or more metals. What did the Federal Safe Drinking Water Act do? It banned solders containing more than 0.2% of lead in piping for use in potable (drinking) water systems. What is the most common solder used on low pressure applications and water lines? 95% tin/5% antimony What is 50/50 tin/antimony alloy used for? Suitable for low/non pressure applications. Provides limited strength. NOT suitable for water lines. Oxygen is supplied in cylinders at pressures of about _______________ psig. 2,000 psig Acetylene cylinders are pressurized to about _______________ psig. 250 psig In an oxy/acetylene setup, the oxygen hose is ______________ and the acetylene hose is _______________________. Oxygen-Green Acetylene - Red To be effective, flashback arrestors must be installed with the flow arrow pointing ____________________ the torch handle. Toward _________________________________ are used for large tubing and heating large surfaces. Rose-bud torch tip What size steel wool is used to clean copper fittings? #00 steel wool What temperature is soldering done below and brazing done above? 842 degrees Joints that have been fluxed shouldn't be left for long periods of time or overnight. True When you solder, where do you apply the flux? Apply the flux to the fitting and the pipe. What type of PPE do you need for soldering and brazing? 1. Eye protection 2. Non-Synthetic Fabrics 3. Long pants and sleeves The distance that a tube inserts into a fitting. Usually determined by a stop inside the fitting. Cup depth A chemical substance that prevents oxides from forming on the surface of metals as they are heated for soldering, brazing or welding. Flux A process that reduces the surface tension so that liquid solder flows evenly throughout the joint. Wetting When is flux needed for brazing? When phosphorus alloys are used with metals other than copper. Filler metals that are used to join copper tubing are of what two groups? Alloys that contain 8-60% silver (BAg series) and Copper Phosphorus (BCuP) alloys. BAg-1 and BAg-2 contain what element which, when heated, can produced toxic fumes? Cadmium