G2 Gas Technician Module 15 A Revised Already Passed

G2 Gas Technician Module 15 A Revised Already Passed What are the two main purposes of gas pressure regulators? To reduce and maintain the downstream pressure and to provide pressure to appliances or burners What are the four categories of a gas pressure regulators? First stage/Service Regulator, Line Pressure Regulator, Appliance Regulator What is lock up pressure and how do you check it? The pressure under which downstream pressure will stabilize after burner shuts down, Check it by closing shut-off valve and measure downstream pressure Where is the hydro-static relief valve used? Liquid Propane between two shut off valves What must the size of the vent piping from a relief device be? Same size as the opening What are the four elements of a direct-operated regulator? Loading Element, Measuring Element, Restricting Element, Atmospheric Vent When flow rate increases through a regulator, what happens to the downstream pressure? Increases What is the maximum allowed propane pressure in a building? 20 Psig What controls the downstream pressure in a regulator? The Loading Element What type of regulator arrangement is required in all permanent propane installations? Two Stage Regulators Will gas flow be interrupted by changing a propane cylinder if an automatic changeover regulator is used on the installation? No What five factors need to be considered before selecting a regulator? Rate of Flow, The Type of Gas, Inlet Gas Pressure, Outlet Gas Pressure and Pipe size What is the purpose of the leak limiter? To allow gas to escape if the diaphram is ruptured Under what conditions can a leak limiter be used? In the event the line regulator doesn't have an internal leak limiter indoors. What is the maximum allowed leakage rate for a leak limiter installed on a natural gas regulator? 2.5 cu ft/hr What is the maximum allowed leakage rate for a leak limiter installed on a propane regulator? 1 cu ft/hr Should the arrow on a regulator body point upstream? No, It should face the direction of flow, downstream What is the minimum clearance allowed between the vent termination of a natural gas regulator and a building opening? 36'' Does a relief valve decrease a regulator's capacity? No What measures the system pressure when using a regulator? Diaphram What types of over-pressure protection incorporate a restricting element? Internal Relief Valves If the type of system and the pressure ranges safely handled by the system are known, how should a relief valve be chosen? By Consulting Manufacturers Tables Does an over-pressure shut-off automatically reset? No What would happen if a regulator vent became blocked with the regulator in the open position? Over pressure situation Name two types of displacement meters. Diaphram & Rotary Which meter corrects for temperature and pressure? Bellows Name the three functions of a diaphragm meter. Consumption, Flow Rate, Leak Test If the smallest test dial moves during a leak test using a meter, what does this indicate? Leak in the gas piping system downstream If the temperature of a gas trapped in a container is increased, what happens to the pressure? Increases If the temperature of a gas decreases in a flexible container, what happens to the volume? It decreases What are the test dials on a meter used for? To calculate the input rating of an appliance, Leak in Gas pipe At what pressure are correction factors used when clocking the meter? When pressure exceeds 1/2 psig Write the standard clocking formula for determining flow rate through a meter for natural gas pressure less than 0.5 psig. 3600 X Dial Size X 1000 /#sec/revolution How long may a 100lb propane cylinder be in used before it must be reinspected and marked? 10 Years If an appliance rating plate is missing, how can the input be determined? Manufacturers/ Orifice Size Table Where is the information on installation clearances for tanks and cylinders? B149.2 What is the defining difference between propane cylinders and tanks? Cylinders are Regulated by Transport Canada, Tanks are Boiler and Pressure Vessel Act What is the size of the largest Cylinder? 1000 Ibs W.C and 420 Ibs Propane What is the relief valve setting of a propane cylinder? 375 psig What is the relief valve setting for a propane tank? 250 psig If a leak occurs in the propane line between the first and second stage regulator, what is the first action that must be taken? Shut off the valve at the outlet of Tank If the relief valve on a refillable propane container opens, what is the first action that must be taken? Apply cold water to the container, it reduces pressure within the container.