Okla. Stat. tit. 40, § 40-141.2

A. This act shall not apply to the following boilers, hot water

heaters and pressure vessels:

1. Pressure vessels used for the transportation of compressed

gases if constructed and operated in compliance with specifications

and regulations of the United States Department of Transportation or

of the Corporation Commission of Oklahoma and any unfired pressure

vessels used as containers for liquefied petroleum gases and subject

to the jurisdiction of the United States Department of

Transportation or the Oklahoma Liquefied Petroleum Gas

Administration or successor agencies;

2. Pressure vessels containing air located on vehicles

operating pursuant to regulations of other jurisdiction authorities;

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3. Pressure vessels having an internal or external operating

pressure not exceeding fifteen (15) pounds per square inch gauge -

one hundred three (103) kilopascals gauge with no limit on size;

4. Pressure vessels having an inside diameter not exceeding six

(6) inches (152mm) with no limitation on pressure;

5. Pressure vessels with a nominal water containing capacity of

one hundred twenty (120) gallons or four hundred fifty (450) liters

or less, to be used for domestic supply purposes, for containing

water under pressure including those containing air, the compression

of which serves only as a cushion;

6. Pressure vessels containing water heated by steam or other

indirect means when none of the following limitations is exceeded:

a. a heat input of two hundred thousand (200,000)

British thermal units per hour - fifty-eight thousand

six hundred (58,600) watts,

b. a water temperature of two hundred ten degrees

Fahrenheit (210º F), or

c. a water containing capacity of one hundred twenty

(120) gallons - four hundred fifty (450) liters;

7. Pressure vessels which may be classified as pressure

containers which are integral parts of components of rotating or

reciprocating mechanical devices such as pumps, compressors,

turbines, generators, engines and hydraulic or pneumatic cylinders

where the primary design considerations and/or stresses are derived

from the functional requirements of the device, or structures whose

primary function is the transport of fluids from one location to

another within a system of which it is an integral part, i.e.,

piping systems;

8. Hot water supply boilers which are directly fired with oil,

gas or electricity when none of the following limitations are

exceeded:

a. a heat input of two hundred thousand (200,000)

British thermal units per hour - fifty-eight thousand

six hundred (58,600) watts,

b. a water temperature of two hundred ten degrees

Fahrenheit (210º F), or

c. a water containing capacity of one hundred twenty

(120) gallons - four hundred fifty (450) liters;

9. Boilers and pressure vessels under federal control and

railroad locomotive boilers;

10. Pressure vessels located on remote sites and limited to

oil and natural gas gathering facilities or processing plants that

have fewer than ten buildings intended for human occupancy per one-

fourth (1/4) square mile and where the closest building is at least

two hundred twenty (220) yards from any vessel;

11. Pressure vessels in the care, custody and control of

research facilities and used solely for research purposes which

Oklahoma Statutes - Title 40. Labor Page 211

require one or more details of noncode construction or which involve

destruction or reduced life expectancy of those vessels; and

12. Hot water supply heaters as defined in subparagraph f of

paragraph 1 of Section 141.1 of this title, with piping connections

to the potable water supply system which are intended to supply hot

water for domestic or commercial purposes other than space heating.

However, the Commissioner shall make routine inspections and issue

necessary orders regarding existing hot water supply heaters located

in facilities or installations owned or operated by the State of
1 of Section 141.1 of this title, with piping connections

to the potable water supply system which are intended to supply hot

water for domestic or commercial purposes other than space heating.

However, the Commissioner shall make routine inspections and issue

necessary orders regarding existing hot water supply heaters located

in facilities or installations owned or operated by the State of

Oklahoma or its agencies, counties, municipalities or school

districts.

B. The following boilers and pressure vessels shall be exempt

from Sections 141.13 through 141.16 of this title:

1. Pressure vessels not exceeding fifteen (15) cubic feet in

volume and two hundred fifty (250) pounds per square inch gauge

pressure;

2. Low pressure steam boilers, hot water heating boilers, hot

water supply boilers, hot water supply heaters or pressure vessels

which are located in private residences or in apartment houses of

less than six-family units; and

3. Pressure vessels operated entirely full of water or other

liquid which is not materially more hazardous than water, provided

the temperature of the vessel contents does not exceed one hundred

fifty degrees Fahrenheit (150º F) or a pressure of two hundred (200)

pounds per square inch gauge.

C. 1. Either a special inspector or an inspector licensed by

the Department of Labor shall inspect exhibitor boilers on an annual

basis when exhibitor boilers are being operated at public events.

Exhibitor boilers maintained by owner/operators for private use and

not for operation for the public shall be exempt from inspection by

this state. Annual inspections by this state or a special inspector

shall consist of the following:

a. an internal and external visual,

b. threaded openings in the boiler may be inspected, when

deemed appropriate, by the inspector after conducting

an internal and external visual,

c. a hydrostatic pressure test at one and twenty-five

one-hundredths (1.25) times the maximum allowable

working pressure,

d. the maximum allowable working pressure shall not

exceed one hundred eighty-five (185) pounds per square

inch (psi),

e. the ash pan and grates on a dry bottom vessel shall be

removed to allow a visual inspection of the crown

sheet,

f. a visual inspection of the crown sheet on wet bottom

boilers,

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g. all boilers shall have a fusible plug that is

constructed to the American Society of Mechanical

Engineers (ASME) code and indicated by an ASME marking

on the filler material. It shall protrude one (1)

inch into the water on a fireside fusible plug and no

more than one (1) inch on a waterside fusible plug,

h. the pressure relief valve shall be National Board

capacity certified,

i. a gage glass shall be present with a guard to protect

the glass, drain valve or petcock, be piped to a safe

location, and be operational,

j. try cocks shall be located in correlation to the

minimum required water level,

k. a pressure gage that has been tested and proven

accurate at the time of the annual pressure test,

l. all piping shall be schedule 80, black pipe (SA-53 B

or SA-105 B) from the boiler to the first valve,

m. the boiler shall be equipped with two means of

supplying feed water while under pressure, and

n. all welding to the boiler shall be done by a certified

repair organization as accredited and described in

Part RA of the National Boiler Inspection Code (NBIC).

2. Exhibitor boilers shall have a nondestructive exam performed

once every five (5) years for determining repairs and thin areas

that need to be repaired. An inspector from the Department of Labor

may perform a random nondestructive exam annually. Results from the

exam may be used by the inspector to waive any time remaining on the

five-year period. A nondestructive exam shall meet the following

requirements:

a. on a dry bottom boiler, no less than 150 readings

shall be taken,
s for determining repairs and thin areas

that need to be repaired. An inspector from the Department of Labor

may perform a random nondestructive exam annually. Results from the

exam may be used by the inspector to waive any time remaining on the

five-year period. A nondestructive exam shall meet the following

requirements:

a. on a dry bottom boiler, no less than 150 readings

shall be taken,

b. on a wet bottom boiler, no less than 180 readings

shall be taken,

c. this exam shall include the areas surrounding the

crown sheet stays and any areas subject to corrosion,

d. a loss of metal that is greater than forty percent

(40%) of the original boiler plate thickness in an

area greater than three (3) inches in diameter shall

be considered to be a thin area and shall need to be

repaired prior to any operation,

e. exams shall be by a certified professional pursuant to

applicable provisions of law of this state,

f. no exam shall be by a certified professional that has

a vested interest in the boiler that is being

examined,

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g. the exam results shall be made available to the

organization where the boiler is being exhibited, if

requested, and

h. the exam results shall be made available at the time

of the annual inspection to the inspector, if

requested.

For purposes of this subsection, "exhibitor boiler" shall mean a

boiler which is operated in this state for nonprofit purposes

including, but not limited to, exhibitions, fairs, parades, farm

machinery shows, or any other event of a historical or educational

nature. An exhibitor boiler includes steam locomotives, traction

and portable steam engines, and stationary boilers of the firetube,

watertube, model or miniature, and may be riveted, riveted and

welded, or all welded construction, if used within the state for

nonprofit purposes.

D. Pressure vessels, associated piping, and connections

located on oil and gas lease sites shall fall under the exclusive

jurisdiction of the Corporation Commission. The Corporation

Commission shall be responsible for the inspection of oil and gas

lease pressure vessels to ensure the vessels, associated piping, and

connections are properly operated and maintained in a manner deemed

appropriate by the Corporation Commission.