Minnesota Special Engineer Boiler License Exam 2025

For the purpose of rating boiler horsepower for an Engineers License only, how many square feet of boiler surface shall be equivalent to one boiler horsepower on a boiler? - 10 Sq. Ft. Heating Surface What is meant by the term "Low Pressure Boiler"? - -Boilers operating at a steam or other vapor pressure of 15psig or less, or a hot water or other liquid boiler in which the pressure does not exceed 160 psig or a temperature of 250 degrees F. A person holding a current State of Minnesota Special Engineers License could be in charge of, or a shift engineer in what size plant(s)? - -High and Low pressure boilers not to exceed a total of 50 boiler horsepower, or a shift engineer in a 100 horsepower plant. Special Engineer may serve as an apprentice of what size water/liquid or steam/vapor boiler? - -In any plant regardless of size under the direct supervision of a properly licensed engineer. The purpose of low water cut out on a steam or hot water boiler is to what? - -Shut off the burner when a low water condition exists. The valve or valves that must relieve all excess pressure on a steam or hot water boiler are what? - -Safety valve and/or an ASME approved safety relief valve. A Tri indicator could be found on a: - -Hot water boiler A tri indicator would inform the boiler operator of what? - -The TEMPERATURE of the water, the PRESSURE of the water in PSIG, and the ALTITUDE of water in feet. What is the destructive force in a steam or hot water boiler explosion? - -The instant release of energy stored in the water as heat. An ASME approved safety relieve calve used on a hot water boiler is tested at the factory on what? - -Steam first then hot water. Some of the things you could find on a steam boiler (or hot water boiler) are what? - Low water cut off, safety valve or safety relief valve, pressure gauge. What devices would only be found on a steam boiler? - -Steam pressure gauge, tricocks, Pressuretrols An expansion tank or compression tank would be used in what? - -Hot water boiler BOILERS BOILERS What is the purpose of the expansion tank? - -To provide for expansion and contraction of the water volume as its temperature varies. On a hot water boiler, what is the purpose of the vent valve? - -To make sure there is water inside the boiler and to vent any trapped air. If the safety valve or ASME safety relief valve leaks you would do what? - -Have the valve repaired or replaced. Tri cocks or gauge cocks are sued on a steam boiler to indicate? - -The true water level inside the boiler. On a steam or hot water boiler, the safety valve or safety relief valve could be tested by? - -When the boiler is running lifting the lever on the valve or raising the pressure until they operate. Before starting a steam or hot water boiler you should check for what? - -Water in the boiler. True or False: Bottom blow down valves are used for both steam and hot water. - -True Safety valves or safety relief valves should be manually tested at least...? - -Monthly The low water cut out is one of the most important electrical/mechanical devices on your boiler. How often should you test it? - -Daily What device must be located between a hot water boiler and the expansion tank? - -A shut off valve so the expansion can be isolated and drained during operation of the boiler. On a hot water boiler, every time the burner operates the safety relief valve opens. Why? - -The expansion tank is water logged, or the isolating valve for the expansion tank is closed. An Aquastat is used on a...? - -Hot water boiler To reduce thermal shock on hot water boilers, what devices are used? - -Low limit or low fire hold control, three way valve, run around pump. On a steam boiler the control named operator will... - -On pressure decrease: Start. On pressure increase: Stop. On a hot water boiler the control called the operator will... - -On temperature decrease: Start. On temperature increase: Stop. BOILERS BOILERS On a steam boiler what is a siphon or pigtail used for? - -To protect the steam gauge from too high of temperature. What is one reason causing the expansion tank to fill with water? - -Air leaks from the gauge glass fitting. What would you do if you cam into a boiler room and found no water in the boiler? - Shut off the burner and allow boiler to cool. What is the purpose of the bottom blow down on a steam boiler? - -To remove sludge and sediment and to drain the boiler. When blowing down the water column the water should do what? - -Refill the gauge glass quickly. When doing the annual boiler inspection the boiler should... - -Water and fire side cleaned and inspection ports open. Purging is part of what cycle? - -Firing cycle All steam traps will prevent steam from passing through them but will allow what to pass through them? - -Dirt, air, and condensate. How do we know if we are using and approved safety valve for a steam boiler or a safety relief valve for a hot water boiler? - -A spring loaded direct acting safety valve or safety relief valve. Before testing a low water fuel cut-out what must be done? - -The burner must be on. Heat can be transferred in how many ways? - -Three. Aqua stats work by sensing: - -Temperature. Name the different ways heat can be transferred and give a definition of each way. - Radiation, Conduction, Convection How many types of boilers are there? - -Three: Fire tube, Water tube, Cast iron sectional What type of boiler can be made larger? - -Cast Iron sectional What type of boiler has the water surrounding the tubes? - -Fire tube What type of boiler has the water running through the tubes? - -Water tube BOILERS BOILERS Boiler room log books area state of Minnesota requirement for ever boiler room, what are some of the things you should be writing down in the book? - -The log entry should start out with today's date NEXT what you did you do in the boiler room NEXT sign your name What is condensate? - -Condensed steam A firing cycle consists of events that safely controls the burning of a fuel. What even occur first? - -Safety controls must be in the circuit. After blowing down the water column and gauge glass you are looking for the: - -Water reentering the gauge glass to rise promptly. Give an example of cold water start for a hot water boiler. - -XXX Two low water fuel cut-outs are required when the BTU input of the burner exceeds: - 750,000 A boiler equipped with the two low water fuel cut-outs must have _______________ on the secondary low water fuel cut-out. - -A manual reset. A boiler with a new burner OR a new boiler room must have: - -A kill switch by each door leaving the boiler room. The low water fuel cut off should be tested: - -At least once a day when the boiler is in operation. What is the purpose of a check valve used in a feed water line going to a steam boiler? - -To restrict the flow in one direction only. Where would you expect to locate pyrometer? - -In the exhaust gases leaving the boiler What would the pyrometer tell you? - -The temperature An aqua state would be used on what type of boiler? - -A hot water boiler Globe valves are used when you need to: - -Thr