815 KAR 15:051.
Heating boiler supplemental requirements - steam heating, hot water heating and
hot water supply boilers.
RELATES TO: KRS
236.030
STATUTORY AUTHORITY:
KRS 236.030
NECESSITY, FUNCTION,
AND CONFORMITY: KRS 236.030 authorizes the executive director, through the
Board of Boiler Rules, to fix reasonable standards for the safe construction,
installation, inspection and repair of boilers and pressure piping. This administrative
regulation sets forth requirements for heating boilers which supplement the
basic requirements for all vessels set forth in 815 KAR 15:025 and 815 KAR
15:026. Many of the provisions have been in effect for some time under the
administrative regulation which preceded this one. This amendment is necessary
to codify additional safety measure applicable only to heating boilers; to
comply with the requirements of KRS Chapter 13A that the administrative
regulation be separated and deal with one (1) topic; and also to allow
mechanical couplings to be used where appropriate.
Section 1. New
Installations. (1) All hot water supply, hot water and steam heating boilers,
except reinstalled boilers and those approved under the "special
design" provisions of 815 KAR 15:025, Section 5, shall be constructed,
stamped, inspected and installed in conformity with the ASME Boiler and
Pressure Vessel Code, Section IV incorporated in 815 KAR 15:025, Section 1(1).
All boilers and pressure vessels shall comply with other applicable provisions
of 815 KAR Chapter 15 of the Kentucky administrative regulations.
(2) Safety valve
requirements for steam boilers.
(a) Each steam
boiler shall have one (1) or more officially rated safety valve of the
spring-pop type adjusted and sealed to discharge at a pressure not to exceed
fifteen (15) psi. Seals shall be attached in a manner to prevent the valve from
being taken apart without breaking the seal. The safety valves shall be
arranged so that they cannot be reset to relieve at a higher pressure than the
maximum allowable working pressure of the boiler. A body drain connection below
seat level shall be provided by the manufacturer and this drain shall not be
plugged during or after field installation. For iron and steel bodied valves
exceeding two (2) inch pipe size, the drain hole, or holes, shall be tapped not
less than three-eighths (3/8) inch pipe size. For valves two (2) inch pipe size
or less, the drain hole shall not be less than one-fourth (1/4) inch in diameter.
(b) Safety valves
for a steam boiler shall not be smaller than one-half (1/2) inch. Safety valves
shall not be larger than four and one-half (4 1/2) inches. The inlet opening
shall have an inside diameter equal to, or greater than, the seat diameter.
(c) The minimum
relieving capacity of valve, or valves, shall be governed by the capacity-marking
on the boiler.
(d) The minimum
valve capacity in pounds per hour shall be the greater of that determined by
dividing the maximum BTU output at the boiler nozzle obtained by the firing of
any fuel for which the unit is installed by 1000, or shall be determined on the
basis of the pounds of steam generated per hour per square foot of boiler
heating surface as given in Table "A." In many cases, a greater
relieving capacity of valves will have to be provided than the minimum
specified by the Table. In every case, the requirements of paragraph (e) of
this subsection shall be met.
TABLE
A
MINIMUM
POUNDS OF STEAM PER HOUR PER
SQUARE
FOOT OF HEATING SURFACE
Fire
Tube
Boilers
Water
Tube
Boilers
Boiler
Heating Surface
Hand
fired
5
6
Stoker
fired
7
8
Oil,
gas or pulverized fuel fired
8
10
Waterwall
Heating Surfaces
Hand
fired
8
8
Stoker
fired
10
12
Oil,
gas or pulverized fuel fired
14
16
1.
When a boiler is fired only by a gas having a heat valve not in excess of 200
BTU per cubic foot, the minimum safety valve or safety relief valve relieving
capacity may be based on the values given for hand fired boilers.
2.
The minimum safety valve or safety relief valve relieving capacity for electric
boilers shall be three and one-half (3 1/2) pounds per hour kilowatt input.
3.
For heating surface determination, see ASME Code for Heating Boilers, paragraph
HG403.
(e)
The safety valve capacity for each steam boiler shall be sufficient to prevent
the pressure from rising more than five (5) psi above the maximum allowable
working pressure when the fuel-burning equipment is installed and operated at
maximum capacity.
(f)
If operating conditions are changed or additional boiler heating surface is
installed, the valve capacity shall be increased, if necessary, to meet the new
conditions and be in accordance with paragraph (e) of this subsection. If
additional valves are required, they may be installed on the outlet piping, if
there is no intervening valve.
(3)
Safety relief valve requirements for hot water heating boilers and hot water
supply boilers.
(a)
Each hot water heating boiler shall have at least one (1) officially rated
pressure relief valve set to relieve at or below the maximum allowable working
pressure of the boiler.
(b)
Each hot water supply boiler shall have at least one (1) officially rated
pressure/temperature safety relief valve of the automatic-reseating type, set
to relieve at or below the maximum allowable pressure of the boiler.
(c)
Safety relief valves officially rated as to capacity shall have pop action when
tested by steam.
(d)
If more than one (1) safety relief valve is used on either hot water heating or
hot water supply boilers, the additional valve or valves shall be officially
rated and may be set within a range not to exceed six (6) psi above the maximum
allowable working pressure up to and including exceeding sixty (60) psi and
five (5) percent for those having a maximum allowable working pressure
exceeding sixty (60) psi, shall be spring loaded and shall be arranged to
prevent resetting at a higher pressure than the maximum permitted in this
subsection.
(e)
Materials which are likely to fail due to deterioration or vulcanization when
subjected to saturated steam temperature corresponding to capacity test
pressure shall not be used for any part.
(f)
Safety relief valves shall not be smaller than three-fourths (3/4) inch, nor
larger than four and one-half (4 1/2) inches, standard pipe size, except that
boilers having a heat input not greater than 15,000 BTU per hour may be
equipped with a rated safety relief valve of one-half (1/2) inch, standard pipe
size; the inlet opening shall have an inside diameter approximately equal to,
or greater than, the seat diameter; and the minimum opening through any part of
the valve shall not be less than one-fourth (1/4) inch diameter, or its
equivalent area.
(g)
The required steam relieving capacity, in pounds per hour, of the pressure
relieving device, or devices, on a boiler shall be the greater of that
determined by dividing the maximum output in BTU at the boiler nozzle obtained
by the firing of any fuel for which the unit is installed by 1000, or shall be
determined on the basis of pounds of steam generated per hour, per square foot
of boiler heating surface, as given in Table A. In many cases a greater
relieving capacity of valves will have to be provided than the minimum
specified by the Table. In every case, the requirements of paragraph (i) of
this subsection shall be met.
(h)
If operating conditions are changed or additional boiler heating surface is
installed, the valve capacity shall be increased, if necessary, to meet the new
conditions and shall be in accordance with paragraph (i) of this subsection.
The additional valves required may be installed on the outlet piping if there
is no intervening valve.
(i)
Safety relief valve capacity for each boiler with a single safety relief valve
shall be such that, with the fuel burning equipment installed and operated at
maximum capacity, the pressure cannot rise more than ten (10) percent above the
maximum allowable working pressure when more than one (1) safety relief valve
is used, the over pressure shall be limited to ten (10) percent above the set
pressure of the highest set valve allowed by subsection (2) of this section.
Section
2. Mechanical Couplings for Heating Boilers. (1) Design limits. If mechanical
pipe couplings are used, the pipe, fittings, couplings and gaskets shall have
design ratings by the manufacturer which meet or exceed the operating control
settings of the boiler itself and shall comply with this section.
(2)
Materials used and location.
(a)
Piping materials listed in the ASME Code, Section IV, shall be used up to the
first stop valve on supply and return piping.
(b)
Mechanical pipe couplings tested and listed by a nationally recognized testing
laboratory may then be used in lieu of flanged, threaded or welded joints
within the complete pressure piping system of boilers in which the operating
temperatures shall not exceed 200 degrees Fahrenheit and operating pressures
shall not exceed 100 psig.
(c)
All mechanical pipe couplings shall be fabricated and installed with strict
adherence to manufacturers written procedures and using only factory approved
tooling.
(d)
Mechanical couplings shall not be installed unless the temperature controls on
the boiler shall be permanently set to prevent operation in excess of 200
degrees Fahrenheit.
(3)
Tests. The mechanical coupling shall be subjected to the same hydrostatic
pressures as are applied to test the strength of the boiler (i.e., up to one
and one-half (1 1/2) times the maximum allowable pressure of the boiler).
(4)
Certification by the contractor. The contractor shall document to the inspector
that the mechanical joints conform to the design and were installed to comply
with the manufacturer procedures, utilizing the materials and equipment
specified and that the temperature and pressure ranges comply with subsection
(2)(b) of this section.
Section
3. Existing Installations, Heating Boilers. (1) ASME Code boilers. The maximum
allowable working pressure of a boiler built in accordance with the ASME Code
shall not exceed the pressure indicated by the manufacturer's identification
stamped or cast upon the boiler or upon a plate secured to it.
(2)
Noncode riveted boilers. The maximum allowable working pressure on the shell of
a noncode riveted heating boiler shall be determined in accordance with 815 KAR
15:040, Section 2 (power boiler installations) except that the maximum
allowable working pressure of a steam boiler shall not exceed fifteen (15) psi
or a hot water boiler shall not exceed 160 psi at a temperature not to exceed
250 degrees Fahrenheit.
(3)
Noncode welded boilers. The maximum allowable working pressure of a noncode
steel or wrought iron heating boiler of welded construction shall not exceed
fifteen (15) psi. For other than steam service, the maximum allowable working
pressure shall be calculated in accordance with Section IV of the ASME Boiler
and Pressure Vessel Code.
(4)
Noncode cast iron boilers.
(a)
The maximum working pressure of a noncode boiler, composed principally of cast
iron, shall not exceed fifteen (15) psi for steam service or thirty (30) psi
for hot water service.
(b)
The maximum allowable working pressure of a noncode boiler having cast iron
shell or heads and steel or wrought iron tubes shall not exceed fifteen (15)
psi for steam service or thirty (30) psi for water service.
(5)
Hydrostatic tests.
(a)
If repairs are necessary which affect the working pressure or safety of a
boiler, it shall be subjected to a hydrostatic test of the greater of sixty
(60) psig or one and one-half (1 1/2) times the maximum allowable working
pressure that is stamped on the boiler with the exception that cast iron steam
boilers shall be subjected to a hydrostatic test of not less than forty-five
(45) psig.
(b)
In making hydrostatic pressure tests, the pressure shall be controlled to
prevent the required test pressure from being be exceeded by more than ten (10)
psig.
(c)
Hydrostatic test water shall be at no less than ambient room temperature, but
in no case less than seventy (70) degrees Fahrenheit, nor high enough to allow
the metal temperature to exceed 120 degrees Fahrenheit.
(d)
The safety valve or safety relief valve shall be removed or each valve disc
shall be held to its seat by means of a testing clamp.
(e)
To test for tightness, the test pressure shall be equal to the relieving
pressure of the safety valve having the lowest relief setting.
(6)
General. If the inspector finds that a steam heating boiler is unsafe for
operation at the pressure previously approved, the pressure shall be reduced,
proper repair made, or the boiler retired from service. (7 Ky.R. 386; eff.
11-6-80; Am. 20 Ky.R. 2735; 2985; eff. 5-18-94; TAm eff. 8-9-2007.)
