Hawaii Administrative Rules
Title 12 - DEPARTMENT OF LABOR AND INDUSTRIAL RELATIONS
Subtitle 8 - HAWAII OCCUPATIONAL SAFETY AND HEALTH DIVISION
Part 10 - PRESSURE RETAINING ITEMS
Chapter 224.1 - PRESSURE VESSELS
Section 12-224.1-5 - Technical installation requirements
Universal Citation: HI Admin Rules 12-224.1-5
Current through November, 2024
(a) All pressure vessels shall be installed as required in section 12-220-2.1 and this chapter. An application for installation permit shall be submitted to the department prior to the commencement of work. Pressure vessels installed without an installation permit may be subject to citations with penalties up to $10,000 per day pursuant to section 12-220-22.
(b) First acceptance inspection and certification. The following shall apply to first acceptance inspections and certifications:
(1) Upon completion of the
installation, the contractor or owner shall arrange for acceptance inspection
with the department;
(2) The
installing contractor shall operationally test the pressure vessel controls and
safety devices prior to scheduling first acceptance inspection with the
department;
(3) The chief boiler
inspector or designated deputy inspector shall conduct the first data
inspection, acceptance inspection, and apply the required state pressure vessel
identification marking; and
(4) The
installing contractor shall test the pressure vessel as directed and witnessed
by the chief boiler inspector or designated deputy inspector.
(c) Clearances. All pressure vessel installations must allow sufficient clearance for normal operation, maintenance, and inspection (internal and external). Except as otherwise authorized by the department, clearances for pressure vessels shall not be less than three (3) feet where inspection openings are provided. Vessels having manholes shall have five (5) feet clearance from the manhole opening and any wall, ceiling, or piping that may prevent a person from entering. All other sides shall not be less than eighteen (18) inches between the vessel and adjacent walls or other structures. Alternative clearances in accordance with the manufacturer's recommendations are subject to acceptance by the department.
(d) Pressure relief devices. All pressure vessels shall be protected by pressure relief devices in accordance with the following requirements:
(1) Device requirements:
(A) Each pressure vessel shall be provided
with pressure relief devices, to protect against overpressure. These pressure
relief devices shall bear the National Board "NB" symbols, the ASME
certification mark, and the appropriate designator, as required by the ASME
BPVC;
(B) Deadweight or weighted
lever pressure relief valves shall not be used;
(C) An unfired steam boiler shall be equipped
with pressure relief valves as required in NBIC Part 1, 2.9;
(D) Pressure relief devices shall be selected
(e.g., material, pressure, etc.) and installed such that their proper
functioning will not be hindered by the nature of the vessel's contents;
and
(E) Relief valves, safety
valves, or safety relief valves shall be of the hand lift lever type whenever
possible to facilitate actuating and testing the device for free
operation;
(2) Number of
devices. At least one device shall be provided for protection of a pressure
vessel. Pressure vessels with multiple chambers with different maximum
allowable working pressures shall have a pressure relief device to protect each
chamber under the most severe coincident conditions;
(3) Location. The following shall apply to
location of devices:
(A) The pressure relief
device shall be installed directly on the pressure vessel, unless the source of
pressure is external to the vessel and is under such positive control that the
pressure cannot exceed the maximum overpressure permitted by the original code
of construction and the pressure relief device cannot be isolated from
the_vessel, except as permitted by NBIC Part 1, 4.5.6(e)(2);
(B) Pressure relief devices intended for use
in compressible fluid service shall be connected to the vessel in the vapor
space above any contained liquid or in the piping system connected to the vapor
space; and
(C) Pressure relief
devices intended for use in liquid service shall be connected below the normal
liquid line. The liquid level during upset conditions shall be
considered;
(4) Capacity.
The following shall apply to the capacity of pressure relief devices:
(A) The pressure relief device(s) shall have
sufficient capacity to ensure that the pressure vessel is not exposed to
pressure greater than that specified in the original code of
construction;
(B) Vessels connected
by a system of piping not containing valves that can isolate any pressure
vessel shall be considered as one unit when determining capacity
requirements;
(C) Heat exchangers
and similar vessels shall be protected with a pressure relief device of
sufficient capacity to avoid overpressure in case of internal failure;
and
(D) The owner shall make
information regarding the basis of pressure relief device selection, including
required capacity, available to the jurisdiction;
(5) Set pressure. The following shall apply
to the set pressure of pressure relief devices:
(A) When a single pressure relief device is
used, the set pressure marked on the device shall not exceed the maximum
allowable working pressure; and
(B)
When more than one pressure relief device is provided to obtain the required
capacity, only one pressure relief device set pressure needs to be at the
maximum allowable working pressure. The set pressures of the additional
pressure relief devices shall be such that the pressure cannot exceed the
overpressure permitted by the code of construction; and
(6) Installation and discharge piping
requirements. The following shall apply to the installation and discharge
piping of pressure relief devices:
(A) The
opening through all pipe and fittings between a pressure vessel and its
pressure relief device shall have at least the area of the pressure relief
device inlet. The characteristics of this upstream system shall be such that
the pressure drop will not reduce the relieving capacity below that required or
adversely affect the proper operation of the pressure relief device. When a
discharge pipe is used, the size shall be such that any pressure that may exist
or develop will not reduce the relieving capacity below that required or
adversely affect the proper operation of the pressure relief device. It shall
be as short and straight as possible and arranged to avoid undue stress on the
pressure relief device;
(B) A
non-reclosing device installed between a pressure vessel and a pressure relief
valve shall meet the requirements of subparagraph (A);
(C) The opening in the pressure vessel wall
shall be designed to provide unobstructed flow between the vessel and its
pressure relief device;
(D) When two
or more required pressure relief devices are placed on one connection, the
inlet cross-sectional area of this connection shall be sized either to avoid
restricting flow to the pressure relief devices or made at least equal to the
combined inlet areas of the pressure relief devices connected to it. The flow
characteristics of the upstream system shall satisfy the requirements of NBIC
Part 1, 4.5.6(e); and
(E) There
shall be no intervening stop valves between the vessel and its pressure relief
device(s), or between the pressure relief device(s) and the point of discharge,
except under the following conditions:
(i)
When these stop valves are so constructed or positively controlled that the
closing of the maximum number of block valves at one time will not reduce the
pressure relieving capacity below the required relieving capacity;
(ii) Upon specific acceptance of the
jurisdiction, when necessary for the continuous operation of processing
equipment of such a complex nature that shutdown of any part is not feasible, a
full area stop valve between a pressure vessel and its pressure relief device
shall be provided for inspection and repair purposes only. This stop valve
shall be arranged so that it can be locked or sealed open, and it shall not be
closed except by an authorized person who shall remain stationed there during
that period of operation while the valve remains closed. The valve shall be
locked or sealed in the open position before the authorized person leaves the
station;
(iii) A full area stop
valve shall also be placed on the discharge side of a pressure relief device
when its discharge is connected to a common header for pressure relief devices
to prevent discharges from these other devices from flowing back to the first
device during inspection and repair. This stop valve shall be arranged so that
it can be locked or sealed open, and it shall not be closed except by an
authorized person who shall remain stationed there during that period of
operation while the valve remains closed. The valve shall be locked and sealed
in the open position before the authorized person leaves the station. This
valve shall only be used when a stop valve on the inlet side of the pressure
relief device is first closed;
(iv)
A pressure vessel in a system where the pressure originates from an outside
source shall have a stop valve between the vessel and the pressure relief
device, and this valve need not be sealed open, provided it also closes off
that vessel from the source of the pressure;
(v) All pressure relief devices shall releive
to a safe point of discharge;
(vi)
Discharge lines from pressure relief devices shall be designed to facilitate
drainage or be fitted with drains to prevent liquid from collecting in the
discharge side of a pressure relief device. The size of discharge lines shall
be such that any pressure that may exist or develop will not reduce the
relieving capacity of the pressure relief device or adversely affect the
operation of the pressure relief device. It shall be as short and straight as
possible and arranged to avoid undue stress on the pressure relief
device;
(vii) Pressure vessel
pressure relief devices and discharge piping shall be safely supported. The
reaction forces due to discharge of pressure relief devices shall be considered
in the design of the inlet and discharge piping. Design of supports,
foundations, and settings shall consider vibration (including seismic when
necessary), movement (including thermal movement), and loadings (including
reaction forces during device operation) in accordance with jurisdictional
requirements, manufacturer's recommendations, and/or other industry standards,
as applicable; and
(viii) Pressure
relief devices shall be installed so they are readily accessible for
inspection, repair, or replacement.
(e) Supports. Pressure vessels and associated piping shall be safely supported. The potential for future pressure tests of the vessel after installation shall be considered when designing vessel supports. Design of supports, foundations, and settings shall consider vibration (including seismic and wind loads where necessary), movement (including thermal expansion and contraction), grounding/bonding to minimumize electrolytic corrosion, and loadings (including the weight of water during a pressure test) in accordance with department requirements, manufacturer's recommendations, and other industry standards, as applicable.
(f) Piping. Piping loads on the vessel nozzles shall be considered. Piping loads include weight of the pipe, weight of the contents of the pipe, and expansion of the pipe from temperature and pressure changes (wind and seismic loads). The effects of piping vibration on the vessel nozzles shall also be considered.
(g) Bolting. All mechanical joints and connections shall conform to the manufacturers' installation instructions and recognized standards acceptable to the jurisdiction.
(h) Instruments and controls. The following shall apply to the instruments and controls of pressure vessels:
(1) Level indicating devices of steam drums
of unfired steam boilers shall be provided with two level indicating devices.
Direct level indicating devices shall be connected to a single water column or
connected directly to the drum, and the connections and pipe shall be not less
than NPS 1/2 (DN 15). Indirect level indicating devices acceptable to the
jurisdiction may be used; and
(2)
The pressure indicating devices of each pressure vessel, or system of pressure
vessels with no intervening valves, shall be equipped with a pressure gage
graduated to not less than one and a half (1-1/2) times nor more than three (3)
times the pressure which the safety or safety relief valve is set.
(i) Isolating valves. Each pressure vessel or multiple pressure vessels connected in series shall have isolating valves which isolate the vessel or vessels from the system in which it or they are installed.
(j) Additional requirements for compressed air vessels. The following shall apply to compressed air vessels:
(1) Under no
circumstances shall an air receiver be buried underground or located in an
inaccessible place;
(2) Belt guards
shall be installed on air compressor units fitted with drive belts;
(3) Drain pipe and valve shall be installed
at the lowest point of every pressure vessel subject to internal corrosion to
provide for draining or the removal of accumulated oil and water from an air
receiver. Adequate automatic traps may be installed in addition to drain
valves. The drain valve on an air receiver shall be opened and drained
frequently at such intervals as to prevent the accumulation of excessive
amounts of liquids in the receiver; and
(4) The use of thermoplastic piping, known as
PVC piping, to transport compressed air or other compressed gases, or the
testing of this piping with compressed air or other compressed gases, in
exposed above ground locations is prohibited. All thermoplastic piping used to
transport compressed air or other compressed gases shall be buried underground
or encased in shatter-resistant materials. In designing a thermoplastic piping
system to transport compressed air or other compressed gases, the strength at
the operating temperature, the pressure, the energetics, and specific failure
mechanisms shall be evaluated.
(k) Additional requirements for hot water storage tanks. The following shall apply to hot water storage tanks:
(1) Temperature and pressure relief devices.
Each potable hot water storage tank shall be equipped with an ASME/NB certified
temperature and pressure relief valve set at a pressure not to exceed the
maximum allowable working pressure and 210 degrees Fahrenheit or the maximum
allowable working temperature of the vessel as designed. The temperature and
pressure relief valve shall meet the requirements of NBIC Part 1 4.5;
(2) Potable hot water storage
tanks exceeding the pressure limit of ASME Code Section IV shall meet the
original code of construction and shall be protected by a pressure relief valve
set not to exceed the vessel's maximum allowable working pressure. A
temperature limiting device shall be installed so that the water inside the
storage tank does not exceed 210 degrees Fahrenheit (99 Celsius). Examples of
temperature limiting devices:
(A) Operating
temperature control and high temperature limit switch with manual reset
installed at the potential source;
(B) Automatic self-adjusting over-temperature
protection;
(C) Tempering and
mixing valves; and
(D) Solenoid
operated dump valves with thermostat probe rated for 210 degrees Fahrenheit
maximum scale range setting;
(3) Clearances and accessibility. In addition
to the clearance requirements under section
12-224.1-5(c),
each hot water storage tank shall have at least twelve (12) inches bottom
clearance; and:
(A) The required nameplate
(marking or stamping) shall be exposed and accessible;
(B) The openings when required shall be
accessible to allow for entry for inspection and maintenance; and
(C) Each hot water storage tank shall meet
the requirements of NBIC Part 1, 4.3.2;
(4) Each hot water storage and potable hot
water storage tank shall have a thermometer so located that it shall be easily
readable at or near the outlet. The thermometer shall be so located that it
shall at all times indicate the temperature of the water in the storage tank;
and
(5) Shut off valves. Each hot
water storage and potable hot water storage tank shall be equipped with stop
valves in the water inlet piping and the outlet piping for the tank to be
removed from service without having to drain the complete system. Each tank
also shall be equipped with a bottom drain valve to provide for flushing and
draining of the vessel.
(l) Additional requirements for tanks and heat exchangers include the following:
(1)
Steam to hot water supply. When a hot-water supply is heated indirectly by
steam in a coil or pipe within the service limitations set forth in NBIC Part
1, 3.2, Definitions, the pressure of the steam used shall not exceed the safe
working pressure of the hot water tank, and a pressure relief valve at least
NPS 1 (DN 25), set to relieve at or below the maximum allowable working
pressure of the tank, shall be applied on the tank;
(2) High-temperature water to water heat
exchanger. When high-temperature water is circulated through the coils or tubes
of a heat exchanger to warm water for space heating or hot-water supply, within
the service limitations set forth in NBIC Part 1, 3.2, Definitions, the heat
exchanger shall be equipped with one or more NB capacity certified pressure
relief valves set to relieve at or below the maximum allowable working pressure
of the heat exchanger, and of sufficient rated capacity to prevent the heat
exchanger pressure from rising more than ten percent (10%) above the maximum
allowable working pressure of the vessel; and
(3) High-temperature water to steam heat
exchanger. When high-temperature water is circulated through the coils or tubes
of a heat exchanger to generate low pressure steam, within the service
limitations set forth in NBIC Part 1, 3.2, Definitions, the heat exchanger
shall be equipped with one or more National Board capacity certified pressure
relief valves set to relieve at a pressure not to exceed fifteen (15) psig (100
kPa), and of sufficient rated capacity to prevent the heat exchanger pressure
from rising more than five (5) psig (34 kPa) above the maximum allowable
working pressure of the vessel. For heat exchangers requiring steam pressures
greater than fifteen (15) psig (100 kPa), refer to NBIC Part 1, Section 2 or
Section 4.
(m) Description and concerns of specific types of pressure vessels.
(1) Compressed air vessels, including
receivers, separators, filters, and coolers. Considerations of concern include
temperature variances, pressure limitations, vibration, and condensation. Drain
connections shall be verified to be free of any foreign material that may cause
plugging; and
(2) Pressure Vessels
for Human Occupancy (PVHOs). The following shall apply to the inspection of
PVHOs:
(A) General and operational. PVHOs
shall be constructed in accordance with ASME PVHO-1, which adopts ASME BPV
Section VIII, therefore, the vessels shall bear a "U" or "U2" ASME designator.
Inspections shall be conducted using ASME PVHO-2 for reference. FOR PVHOs
manufactured from non-traditional materials, such as fabrics, PVHO-1 Code Cases
shall apply and have all the documentation required by the code case, but not
necessarily have any related section ASME BPV Section VIII forms;
(B) Cast and ductile iron fittings are not
allowed;
(C) Due to the human
occupancy element, a person shall be in attendance to monitor the PVHO when in
operation, in the event there is an accident;
(D) The installation shall be such that there
is adequate clearance to inspect it properly. In some applications, such as
underground tunneling, it may be impossible to perform a complete external
inspection;
(E) Internal
inspection. Where existing openings permit, perform a visual internal
inspection of the vessel. Look for any obvious cracks and note areas that are
subject to high stress such as welds, welded repairs, head-to-shell
transitions, sharp interior corners, and interior surfaces opposite external
attachments or supports. The vessel shall be free of corrosion, damage, dents,
gouges, or other damage. All openings leading to external fittings or controls
shall be free from obstruction. All exhaust inlets shall be checked to prevent
a chamber occupant from inadvertently blocking the opening;
(F) External inspection. The inspector shall
closely examine the external condition of the pressure vessel for corrosion,
damage, dents, gouges, or other damage. The lower half and the bottom portions
of insulated vessels shall receive special focus, as condensation or moisture
may gravitate down the vessel shell and soak into the insulation, keeping it
moist for long periods of time. Penetration locations in the insulation or
fireproofing such as saddle supports, sphere support legs, nozzles, or fittings
shall be examined closely for potential moisture ingress paths. When moisture
penetrates the insulation, the insulation may actually work in reverse, holding
moisture in the insulation or near the vessel shell. Insulated vessels that are
run on an intermittent basis or that have been out of service require close
scrutiny. In general, a visual inspection of the vessel's insulated surfaces
shall be conducted once per year. The most common and superior method to
inspect for suspected corrosion under insulation (GUI) damage is to completely
or partially remove the insulation for visual inspection. The method most
commonly utilized to inspect for GUI without insulation removal is by X-ray and
isotope radiography (film or digital), or by real time radiography, utilizing
imaging scopes and surface profilers. The real-time imaging tools will work
well if the vessel geometry and insulation thickness allows. Other less common
methods to detect GUI include specialized electromagnetic methods (pulsed eddy
current and electromagnetic waves) and long-range ultrasonic techniques (guided
waves). There are also several methods to detect moisture soaked insulation,
which is often the beginning for potential GUI damage. Moisture probe
detectors, neutron backscatter, and thermography are tools that can be used for
GUI moisture screening. Proper surface treatment (coating) of the vessel
external shell and maintaining weather-tight external insulation are the keys
to prevention of GUI damage;
(G)
Inspection of parts and appurtenances (e.g., piping systems, pressure gage,
bottom drain). As stated above, cast iron is not allowed on PVHOs and shall be
replaced with parts fabricated with other suitable materials, in accordance
with ASME BPVG Section II. If valves or fittings are in place, check to ensure
that these are complete and functional. The inspector shall note the pressure
indicated by the gage and compare it with other gages on the same system. If
the pressure gage is not mounted on the vessel itself, it shall be ascertained
that the gage is installed on the system in such a manner that it correctly
indicates actual pressure in the vessel. The inspector shall verify that the
vessel is provided with a drain opening. The system shall have a pressure gage
designed for at least the most severe condition of coincident pressure in
normal operation. This gage shall be clearly visible to the person adjusting
the setting of the pressure control valve. The graduation on the pressure gage
shall be graduated to not less than one and a half (1.5) times the maximum
allowable working pressure (MAWP) of the vessel. Provisions shall be made to
calibrate pressure gages or to have them checked against a standard test gage.
Any vents and exhausts shall be piped at least ten (10) feet from any air
intake. Venting shall be provided at all high points of the piping
system;
(H) Inspection of view ports
and windows. Each window shall be individually identified and be marked in
accordance with PVHO-1. If there are any penetrations through windows, they
must be circular. Windows must be free of crazing, cracks, and scratches.
Windows and viewports have a maximum interval for seat or seal inspection and
refurbishment. Documentation shall be checked to ensure compliance with PVHO-2,
Table 2-4.3-1, Table 2-4.3-2 (see Exhibit 1); and
(I) Inspection of pressure relief devices.
Pressure relief devices must have a_quick opening manual shutoff valve installed between the chamber and the pressure relief device, with a frangible seal in place, within easy access to the operator. The pressure relief device shall be constructed in accordance with ASME BPVC Section VIII. The discharge from the pressure relief device must be piped outside to a safe point of discharge. Rupture disks may be used only if they are in series with a pressure relief valve, or when there is less than two (2) cubic feet of water volume. Verify that the safety valve is periodically tested either manually by raising the disk from the seat or by removing and testing the valve on a test stand.
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