MN Special Boilers License Preparation Test Latest

MN Special Boilers License Preparation Test Latest Special (License Grade) - Work in any type of plant Grade C (License Grade) - Can operate low-pressure steam or hot water (no steam engines/turbines) Grade B (License Grade) - Can operate high-pressure or low-pressure steam or hot water (no steam engines/turbines) Grade A (License Grade) - Can operate any plant including plants with steam engines/turbines Special (License Class) - Take Charge (max 50 hpr) Shift Engineer (max 100 hpr) 2nd Class (License Class) - Take Charge (max 100 hpr) Shift Engineer (max 500 hpr) 1st Class (License Class) - Take Charge (max 500 hpr) Shift Engineer (unlimited hpr) Chief (License Class) - Take Charge (unlimited hpr) Shift engineer (unlimited hpr) Shift Engineer - Can operate and take responsibility for the plant while on duty Take Charge - You are the main person in charge of the plant. You supervise shift engineers. 1 boiler horsepower = - = 10 sq. Ft of heating surface 8.3 - 1 gallon of water weighs _____ pounds 10 kilowatts (for licensing) - _____ kilowatts = 1 horsepower 67,000 BTU/hr (for licensing) - __________ BTU/hr = 1 horsepower In the boiler room - Where should a boiler license be displayed? One BTU - What will raise one pound of water by one degree F Check water level - When entering a steam boiler room what is the first thing an operator should do? Above 15 psi, above 160 psi water, and temps above 250°F - A high pressure boiler is classified as such when what - ? A.S.M.E. Approved - What type of safety valve is required? Efficiency - When operating a boiler, what is most important? Shuts off fuel in case of low water - How does a low water fuel cut off (LWCO) protect a boiler? shut off the burner when a low water condition exists. - If you cannot determine water level what do you do? No - Can you compress a liquid? Cast Iron Sectional and Firebox - What boilers are low pressure only? Push nipples and Tie Rods - What holds cast iron sections together? At least as big as the largest incoming wire - On electric boilers, how large should the ground wire be? Baffle - Directs flow of combustion gasses, water, and/or steam Passes - Amount of times the heat moves through the tubes in a fire tube boiler Refractory - Hard surface insulation (brick, concrete,...) Stays - Helps keep shape and position of boiler Tubing - Measured by Outside Diameter (OD) Package Boiler - Comes completely assembled with its own feedwater pumps, fuel system & draft fans Firetube, Watertube, Cast Iron - The 3 basic types of boilers (per ASME) are: Pressure Controls - Steam boilers have __________ ___________ to control burner (turn burner on and off) Aquastat - Hydronic systems have a(n) ______________ to turn the burner on or off Low water cut off - What prevents thermal shock in a hydronic system? Cast iron section boiler - Inexpensive Corrosion resistance Brittle Low pressure only Comes in sections Firetube boilers - Used for small to medium plants Fire inside tubes, water outside Measure by amount of heat transfer surface Scotch Marine The HRT (horizontal return tubular) Locomotive Vertical firetube Firebox - What are five types of firetube boilers? Scotch Marine - Internal furnace Furnace made of corrugated tube (Morrison tube) Can be wetback or dryback Wetback - More efficient Water jacketed Harder to perform maintenance Dryback - Less efficient Refractory backed Easier to maintenance Gas flames - What flames are generally blue? Oil flames - What flames are white-ish/yellow? HRT (horizontal return tubular) - Externally fired Suspended by slings over furnace Locomotive - Portable and compact Single pass Vertical firetube - Single pass Turbulator Gas water heater Turbulator - Type of baffle that has three (3) twists Firebox - Two pass Low pressure only Uses stays They are expanded at the ends to support tube sheet then flared or beaded - How are firetubes held in place? Watertube boilers - Two (2) or more pressure vessels connected by tubes Water inside tubes A, D, O - What are the common types of watertube boilers? Removes sludge Control chemistry Control water level Can drain the boiler - What are reasons for a blowdown? Breeching - Connects boiler to the stack Economizer (preheats feed water) Air preheater (preheats combustion air) - What are two types of heat exchangers? Less than five (5) turns - How many turns equals a quick valve? Quick valve - Which valve do you open first and shut last? Two (2) valves - How many bottom blowdown valves are needed for pressures over 100 pounds? 150 degrees Fahrenheit - What is the max temperature you can send water down the sewer? Steam drum on top Mud drum on bottom - In a watertube boiler, which pressure drum is on top and which is on bottom? Adds sensible heat to steam - What is a superheater?