A Fourth Class operator wants the Third Class license. How much experience as a Fourth Class Boiler Operator does the rule ask for?OAC 380:25-19-1(k)(3)(B)
An applicant for the Fourth Class license has worked only under a qualified boiler operator. How long must that supervised experience be?OAC 380:25-19-1(k)(4)(B)
An applicant holds a stationary engineer license from another jurisdiction. Under Oklahoma's rule, what may it do?OAC 380:25-19-1(e)
An Oklahoma Boiler Operator License was not renewed within 90 days of its expiration date. What follows?OAC 380:25-19-1(g)
Before an Oklahoma Boiler Operator License is suspended, what is the licensee entitled to?OAC 380:25-19-1(j)
Besides experience, what else can qualify a person to sit for Oklahoma's Fourth Class examination?OAC 380:25-19-1(k)(4)(B)
Besides the Chief or a Deputy Boiler Inspector, who may give the Oklahoma Boiler Operator License test?OAC 380:25-17-4(c)
Does Oklahoma law require every person who runs a boiler to hold the state Boiler Operator License?OAC 380:25-19-1(c)
Does the Oklahoma Boiler Operator License let its holder repair boilers for other companies?OAC 380:25-19-1(h)
How long is an Oklahoma Boiler Operator License valid?OAC 380:25-19-1(g)
How many classes of Boiler Operator License do Oklahoma's rules set out?OAC 380:25-19-1(k)
Show all 120 questions (109 more)
Boiler operator license: classes, examination, renewal, continued
How recently must an applicant have completed the license requirements before the Oklahoma examination date?OAC 380:25-19-1(e)
Is the Oklahoma Boiler Operator License examination open book?OAC 380:25-17-4(a)
On what day does an Oklahoma Boiler Operator License expire?OAC 380:25-19-1(g)
The Second Class license asks for three years of documented experience. How much of it must be with power boilers?OAC 380:25-19-1(k)(2)(B)
Under Oklahoma's fee rule, what is the most the Department of Labor may charge for a boiler operator license?OAC 380:25-1-3(d)
What can stand in for one year of supervisory experience toward Oklahoma's First Class license?OAC 380:25-19-1(k)(1)(B)
What is the highest energy input a Fourth Class Boiler Operator License covers in Oklahoma?OAC 380:25-19-1(k)(4)(A)
What is the highest steam pressure a Fourth Class operator may run in Oklahoma?OAC 380:25-19-1(k)(4)(A)
What is the minimum passing grade on the Oklahoma Boiler Operator License examination?OAC 380:25-17-4(b)
What kinds of questions may the Oklahoma Boiler Operator License examination use?OAC 380:25-17-4(a)
What may the holder of an Oklahoma First Class Boiler Operator License operate?OAC 380:25-19-1(k)(1)(A)
Where does an Oklahoma Third Class Boiler Operator License stop, by energy input?OAC 380:25-19-1(k)(3)(A)
Which bodies may adopt Oklahoma's boiler operator licensing program for people in their employ or jurisdiction?OAC 380:25-19-1(a)
Which boilers are outside the Oklahoma Boiler Operator License?OAC 380:25-19-1(h)
Which class of Oklahoma Boiler Operator License is the supervisory level license?OAC 380:25-19-1(k)(1)
Which equipment may a state-licensed boiler operator inspect under the Oklahoma Act?40 O.S. § 141.13(C)
Which of these is a ground for suspending an Oklahoma Boiler Operator License?OAC 380:25-19-1(j)
Which Oklahoma license class first allows boilers with energy inputs above 12,500,000 Btu per hour?OAC 380:25-19-1(k)(2)(A)
Who decides how often a licensed operator must attend a boiler in an Oklahoma jurisdiction that adopted the program?OAC 380:25-19-1(i)
Who may apply for the Oklahoma Boiler Operator License?OAC 380:25-19-1(b)
Who prepares, distributes and grades the Oklahoma Boiler Operator License examination?OAC 380:25-17-4(a)
Definitions: boiler kinds and their limits 12
A "low pressure steam boiler" in Oklahoma operates at pressures not exceeding what?40 O.S. § 141.1(1)(c)
The controls of an Oklahoma "hot water supply heater" must keep the water from exceeding what temperature?40 O.S. § 141.1(1)(f)
How does the Oklahoma Act define a "power boiler"?40 O.S. § 141.1(1)(a)
In Oklahoma's rules, what sets an "internal inspection" apart from an external one?OAC 380:25-1-2
Under Oklahoma's rules, what is a "second-hand" boiler?OAC 380:25-1-2
Up to what limits is a boiler a "hot water heating boiler" under the Oklahoma Act?40 O.S. § 141.1(1)(d)
What do Oklahoma's rules call a boiler that bears no ASME stamp and no stamp of a jurisdiction with an equivalent standard?OAC 380:25-1-2
What is a "certificate of operation" under the Oklahoma Act?40 O.S. § 141.1(3)
What is the highest maximum allowable working pressure of a "miniature boiler" in Oklahoma's rules?OAC 380:25-1-2
What makes a water boiler a "high-temperature water boiler" in Oklahoma?40 O.S. § 141.1(1)(b)
Which of these is NOT an "accident or incident" under Oklahoma's boiler rules, absent an unusual explosion hazard?OAC 380:25-1-2
Who is the "owner or user" in Oklahoma's boiler rules?OAC 380:25-1-2
What the Act covers and exempts 8
A directly fired hot water supply boiler is exempt from the Oklahoma Act only if its heat input stays at or under what figure?40 O.S. § 141.2(A)(8)
A low pressure steam boiler heats an Oklahoma apartment house of four family units. Which parts of the Act is it exempt from?40 O.S. § 141.2(B)(2)
At what pressure is the annual hydrostatic test of an Oklahoma exhibitor boiler made?40 O.S. § 141.2(C)(1)
How often must an Oklahoma exhibitor boiler be inspected when it is operated at public events?40 O.S. § 141.2(C)(1)
How often must an Oklahoma exhibitor boiler have a nondestructive exam for thin areas?40 O.S. § 141.2(C)(2)
What water capacity is the limit for an exempt, directly fired hot water supply boiler under the Oklahoma Act?40 O.S. § 141.2(A)(8)
Which boilers does the Oklahoma Boiler and Pressure Vessel Safety Act not apply to at all?40 O.S. § 141.2(A)(9)
Who has exclusive jurisdiction over pressure vessels on Oklahoma oil and gas lease sites?40 O.S. § 141.2(D)
Inspections, tests and certificates of operation 15
A lap seam crack is found along a longitudinal riveted joint of an Oklahoma boiler shell. What do the rules require?OAC 380:25-7-5
Before entering an Oklahoma boiler tied to a common header with other boilers, what is done with its nonreturn and steam stop valves?OAC 380:25-7-2(1)(G)
During a hydrostatic test in Oklahoma, how are the safety valves handled?OAC 380:25-7-6(b)
How much grace does the Oklahoma Act allow between inspections, beyond the stated period?40 O.S. § 141.13(B)(6)
How much notice of the inspection date do Oklahoma's rules give an owner to prepare a boiler?OAC 380:25-7-2
How often does an Oklahoma low pressure steam heating boiler get an internal inspection, where construction permits?40 O.S. § 141.13(B)(2)
How often must an Oklahoma power boiler be inspected?40 O.S. § 141.13(B)(1)
In Oklahoma, running a boiler at a pressure above the one on its certificate of operation is what?40 O.S. § 141.15
May an Oklahoma inspector make an external inspection without telling the owner first?OAC 380:25-3-3
What is the lowest water temperature allowed for a hydrostatic test under Oklahoma's rules?OAC 380:25-7-6(c)
What is the most a hydrostatic pressure test may be under Oklahoma's general rule?OAC 380:25-7-6(a)
Where must an Oklahoma boiler's certificate of operation be kept?40 O.S. § 141.14(B)
Which step is part of preparing an Oklahoma boiler for internal inspection?OAC 380:25-7-2(1)
Who decides whether an Oklahoma hot water heating boiler gets an internal inspection?40 O.S. § 141.13(B)(3)
Who may suspend an Oklahoma certificate of operation at any time when a boiler is deemed a menace to public safety?40 O.S. § 141.14(C)
Accidents, repairs and penalties 13
A boiler accident happens in Oklahoma. What must the owner, user or operator do at once?40 O.S. § 141.18(B)
After an explosion, when may parts of an Oklahoma boiler be moved before the Commissioner gives permission?OAC 380:25-3-12
An Oklahoma inspector lowers a boiler's working pressure and the owner disagrees. Where does the owner appeal?OAC 380:25-3-22
An operator resets a safety valve so the boiler can run above the pressure on its Oklahoma inspection certificate. Is that allowed?OAC 380:25-3-25(c)
Before welded repairs are made to an Oklahoma boiler, what must happen first?OAC 380:25-3-23(a)
By what instructions must an Oklahoma boiler be operated and maintained?OAC 380:25-7-17
How is a condemned boiler marked in Oklahoma?OAC 380:25-3-17(a)
How long does a person have to contest an Oklahoma boiler fine by asking for a hearing?OAC 380:25-3-29(c)
May an Oklahoma owner or user do minor repairs and maintenance on its own boiler without a repair license?OAC 380:25-13-1(c)
May work be done on a safety appliance of an Oklahoma boiler while the appliance is under pressure?OAC 380:25-3-25(a)
What is the most the Oklahoma Commissioner of Labor may assess as an administrative fine under the boiler rules?OAC 380:25-3-29(b)
What must happen before a used or secondhand boiler is installed in Oklahoma?OAC 380:25-3-20
Who may repair a safety valve under Oklahoma's rules?OAC 380:25-3-25(d)
Existing power boilers: safety valves, feed, gages, blowoff 17
Above what water-heating surface must an Oklahoma power boiler have two or more safety valves?OAC 380:25-5-10(b)
An Oklahoma power boiler has more than 500 square feet of water heating surface. How must it be fed?OAC 380:25-5-11(b)
At least one safety valve on an Oklahoma power boiler is set at or below the maximum allowable working pressure. How high may the others be set?OAC 380:25-5-10(f)
How far must the dial of a steam gage on an Oklahoma power boiler be graduated?OAC 380:25-5-13(a)
How must a safety valve stand when connected to an Oklahoma boiler?OAC 380:25-5-10(c)
May a stop valve be placed between an Oklahoma power boiler and its safety valve?OAC 380:25-5-10(d)
Oklahoma boilers with manholes share a common steam main. What must each boiler's steam connection have?OAC 380:25-5-14(c)
What is the maximum allowable working pressure of a cast iron steam boiler in Oklahoma?OAC 380:25-5-9
What is the siphon on an Oklahoma boiler's steam gage connection for?OAC 380:25-5-13(a)
What may not be used as replacement parts when Oklahoma power boiler fittings are repaired?OAC 380:25-5-16
What valves do Oklahoma's rules require in the feed piping to a power boiler?OAC 380:25-5-11(d)
When a globe valve is used on Oklahoma boiler feed piping, where must the inlet be?OAC 380:25-5-11(d)
When must an Oklahoma power boiler's blowoff pipe have two valves, or a valve and a cock?OAC 380:25-5-15(c)
Which safety valve is prohibited on an existing Oklahoma power boiler?OAC 380:25-5-10(a)
Which valve may not be used on the blowoff pipe of an Oklahoma power boiler?OAC 380:25-5-15(c)
Why must each Oklahoma power boiler have a quarter inch or larger nipple and globe valve on the steam space?OAC 380:25-5-13(c)
With every safety valve open, how far may the pressure of an Oklahoma power boiler rise above the highest set pressure?OAC 380:25-5-10(e)
A steam stop valve can close an Oklahoma heating boiler off from its system. What must the condensate return line then have?OAC 380:25-5-29(a)
An Oklahoma hot water heating system is designed to run at 30 psi or less. What test pressure must its expansion tank be designed for?OAC 380:25-5-33(b)
At what pressure must the safety valve of an Oklahoma steam heating boiler discharge?OAC 380:25-5-25(a)(1)
How is the pressure or altitude gage of an Oklahoma hot water boiler graduated?OAC 380:25-5-27(b)
How many pressure-operated controls must protect an automatically fired steam heating boiler in Oklahoma?OAC 380:25-5-27(e)
The safety relief valve capacity of an Oklahoma hot water boiler must keep the pressure from rising more than how far above the maximum allowable working pressure?OAC 380:25-5-25(b)(6)
Through which connection may feedwater enter an Oklahoma heating boiler?OAC 380:25-5-30(a)
What is the smallest safety relief valve allowed on an Oklahoma hot water boiler with a heat input above 15,000 Btu per hour?OAC 380:25-5-25(b)(3)
What must an Oklahoma boiler with a condensate return pump be provided with?OAC 380:25-5-31
What must the lower fitting of the water gage glass on an Oklahoma steam heating boiler have?OAC 380:25-5-28(a)
What must the thermometer on an Oklahoma hot water boiler show at all times?OAC 380:25-5-27(d)
What range must the steam gage dial of an Oklahoma steam heating boiler cover?OAC 380:25-5-26(b)
When the high limit temperature control of an automatically fired Oklahoma hot water boiler trips, what must it do?OAC 380:25-5-27(f)(1)
With the burner at maximum, how far may the pressure of an Oklahoma steam heating boiler rise above its maximum allowable working pressure?OAC 380:25-5-25(a)(5)
General requirements: low water cutoff, clearance, exits, air 9
A pressure reducing valve feeds Oklahoma piping that cannot take the full inlet pressure. What must the low pressure side have?OAC 380:25-7-8(a)
An Oklahoma boiler room gets its combustion air from a fan. What must the fan be tied to?OAC 380:25-7-18(c)
Boiler blowdown in Oklahoma is to enter a sanitary sewer. What must it pass through first?OAC 380:25-7-9(a)
How many automatic low water fuel cutoffs must an automatically fired steam boiler have in Oklahoma?OAC 380:25-7-7(a)
How much clearance must a newly installed Oklahoma boiler have from adjacent walls?OAC 380:25-7-14
How much clearance must an Oklahoma boiler's manhole opening have from a wall, ceiling or piping?OAC 380:25-7-14
What kind of latch must the firing doors of an Oklahoma watertube boiler have if they do not open inward?OAC 380:25-7-13(b)
When must the low water fuel cutoff of an Oklahoma boiler cut off the fuel supply?OAC 380:25-7-7(a)
Which Oklahoma boiler rooms need at least two exits, remote from each other?OAC 380:25-7-16
This unofficial Oklahoma boiler operators practice test asks 120 of our own questions on the state's Boiler and Pressure Vessel Safety Act and its boiler rules. It is not affiliated with the Oklahoma Department of Labor.
Read the full guide
What the state says about the exam
The Department of Labor prepares and grades the Boiler Operator License examination. Its rule, OAC 380:25-17-4, sets a closed book test of multiple choice, true or false or essay questions, with 70% the minimum passing grade.
What this bank covers
Every question comes from the Act or the Department's rules: the four license classes, inspections and certificates of operation, accident and repair duties, and the safety valves, gages, feed, blowoff and controls the rules require on existing boilers.
What is left out
Combustion, water treatment and boiler arithmetic are not asked, because Oklahoma publishes no text for them. The national codes the rules adopt are privately published and were not used.
A license lasts two years and expires on the last day of your birth month. Past 90 days late, it is a new issuance.
Fourth Class takes one year of experience, six months under a qualified operator, or an acceptable training course, then the written examination.
Questions and answers
Does Oklahoma require a boiler operator license?
Not statewide. OAC 380:25-19-1 lets any company, school, city, county or other governmental agency adopt the licensing program for the people it employs or governs, and any individual may apply. Nothing else in the rule makes the license mandatory.
How many questions are on the Oklahoma boiler operator test?
The Department of Labor publishes no question count, time limit or subject list; a 25-question round here is our own length, not the state's. The Department approves schools to give the test under its Body of Knowledge document; ask the Chief Boiler Inspector's office.
What are the Oklahoma boiler operator license classes?
Four. Fourth Class covers steam to 15 psig and hot water boilers, up to 5,000,000 Btu per hour. Third Class reaches 12,500,000. Second Class goes above that. First Class adds supervising others on any single burner boiler.
How do I get a boiler operator license in Oklahoma?
Apply on the Department of Labor's Boiler Operator License Application, show the experience or training your class asks for, gained within five calendar years of the test, and pass the examination. The form lists $100 for a new license, $25 for a change of class.
Are these questions from the real Oklahoma exam?
No. Each was written for this page from the Act and rules in the Department of Labor's booklet, current as of July 11, 2025. None comes from the state examination, and the Department did not review this page.