|Adopt Entire Chapter||X||X||X||X||X||X|
|Adopt Entire Chapter as amended (amended sections listed below)||X||X||X||X||X|
|Adopt only those sections that are listed below|
The Office of the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.
Exception: Ammonia refrigeration systems shall comply with IIAR 2, IIAR 3, and IIAR 5.
Exception: Lithium bromide absorption systems using water as the refrigerant.
|REFRIGERANT||CHEMICAL FORMULA3||CHEMICAL NAME1
(COMPOSITION FOR BLENDS)
|POUNDS PER 1000
CUBIC FEET OF SPACE
|R-14||CF4||Tetrafluoromethane (carbon tetrafluoride)||A1||1000||25|
|R-30||CH2Cl2||Dichloromethane (methylene chloride)||B1||-||-|
|R-32||CH2F2||Difluoromethane (methylene fluoride)||A2L||1000||4.8|
|R-40||CH3Cl||Chloromethane (methyl chloride)||B2||-||-|
|R-113||CCl2FCClF2||1, 1, 2-trichloro-1, 2, 2 - trifluoro
|R-114||CClF2CClF2||1, 2-dichloro-1, 1, 2, 2 tetrafluoro
|R-123||CHCl2CF3||2, 2-dichloro-1, 1, 1, - trifluoroethane||B1||50||3.5|
|R-124||CHClFCF3||2-chloro-1, 1, 2, 2 - tetrafluoroethane||A1||1000||3.5|
|R-134a||CH2FCF3||1, 1, 1, 2-tetrafluoroethane||A1||1000||13|
|R-141b||CH3CCl2F||1, 1-dichloro- 1 -fluoroethane||-||500||0.78|
|R-142b||CH3CClF2||1-chloro-1, 1 -difluoroethane||A2||1000||5.1|
|R-143a||CH3CF3||1, 1, 1-trifluoroethane||A2L||1000||4.5|
|R-152a||CH3CHF2||1, 1 -difluoroethane||A2||1000||2.0|
|R-227ea||CF3CHFCF3||1, 1, 1, 2, 3, 3, 3-heptafluoropropane||A1||1000||36|
|R-236fa||CF3CH2CF3||1, 1, 1, 3, 3, 3-hexafluoropropane||A1||1000||21|
|R-245fa||CHF2CH2CF3||1, 1, 1, 3, 3-pentafluoropropane||B1||300||12|
|R-610||CH3CH2OCH2CH3||Ethoxyethane (ethyl ether)||-||400||-|
|R-1233zd(E)||CF3CH=CHCl||Trans- 1 -chloro- 3, 3, 3-trifluoro- 1 -
|R-1234yf||CF3CF=CH2||2, 3, 3, 3-tetrafluoro- 1 -propane||A2L||500||4.7|
|R-1234ze(E)||CF3CH=CHF||Trans-1, 3, 3, 3- tetrafluoro- 1- propene||A2L||800||4.7|
1 The preferred name is followed by the popular name in parenthesis.
2 The OEL are 8-hour TWA; a C designation denotes a ceiling limit.
3 Azeotropic refrigerants exhibit some segregation of components at conditions of temperature and pressure other than those at which they where formulated. The extent of segregation depends on the particular azeotrope and hardware system configuration.
4 The exact composition of this azeotrope is in question and additional experimental studies are needed.
5 R-507, R-508, and R-509 shall be permitted as alternative designations for R-507A, R-508A, and R-509A due to a change in designations after assignment of R-500 through R-509. Corresponding changes were not made for R-500 through R-506.
6 The amount of refrigerant per occupied space values for these refrigerant blends are approximated in the absence of adequate data for a component comprising less than 4 percent m/m of the blend and expected to have a small influence in an acute, accidental release.
7 Refrigerant flammability classification of Class 2L shall comply with the requirements for flammability classification or Class 2.
- Laboratories with more than 100 square feet (9.29 m2) of space per person.
- Industrial occupancies.
- Listed portable-unit systems containing not more than 0.331 pounds (0.150 kg) of Group A3 refrigerant, provided that the equipment is installed in accordance with the listing and the manufacturer's installation instructions. [ASHRAE 15:7.5.3]
|A-1||Group A1 only||Any||Any|
|A-2||Group A1 only||Any||Any|
|A-3||Group A1 only||Any||Any|
|A-4||Group A1 only||Any||Any|
|B||Group A12 only||Any||Any|
|E||Group A1 only||Any||Any|
|F-1||Group A12 only||Any||Any|
|H-4||Group A1 only||Any||Any|
|H-5||Group A1 only||Any||Any|
|I-2||Group A1 only||Any||Any|
|[OSHPD 1, 2, 3 & 4]||I-2.1||Group A1 only||Any||Any|
|I-4||Group A1 only||Any||Any|
|M||Group A12 only||Any||Any|
|R-1||Group A1 only||Any||Any|
|R-2||Group A1 only||Any||Any|
|R-3||Group A1 only||Any||Any|
|R-4||Group A1 only||Any||Any|
|S-1||Group A12 only||Any||Any|
- Listed equipment containing not more than 6.6 pounds (2.99 kg) of refrigerant, regardless of the refrigerant safety classification, provided the equipment is installed in accordance with the listing and with the manufacturer's installation instructions.
- Listed equipment for use in laboratories with more than 100 square feet (9.29 m2) of space per person, regardless of the refrigerant safety classification, provided that the equipment is installed in accordance with the listing and the manufacturer's installation instructions. [ASHRAE 15:7.2]
Exceptions: The following closure devices shall not be considered:
- Smoke dampers, fire dampers, and combination smoke and fire dampers that close only in an emergency not associated with a refrigerant leak.
- Dampers, such as variable-air-volume (VAV) boxes, that provide limited closure where airflow is not reduced below 10 percent of its maximum with the fan running. [ASHRAE 15:22.214.171.124]
- The space(s) containing the machinery is (are) separated 206 from other occupancies by tight construction with tight-fitting doors.
- Access is restricted to authorized personnel.
- The floor area per occupant is not less than 100 square
feet (9.29 m2).
Exception: The minimum floor area shall not apply where the space is provided with egress directly to the outdoors or into approved building exits.
- Refrigerant detectors are installed with the sensing location and alarm level as required in refrigeration machinery rooms in accordance with Section 1106.4.
- Open flames and surfaces exceeding 800°F (427°C) shall not be permitted where a Group A2, B2, A3, or B3 refrigerant, other than R-717 (ammonia), is used.
- Electrical equipment that is in accordance with Class 1, Division 2, of NFPA 70 where the quantity of a Group A2, B2, A3, or B3 refrigerant other than R-717 (ammonia) in an independent circuit is capable of exceeding 25 percent of the lower flammability limit (LFL) upon release to the space based on the volume determined in accordance with Section 1104.2.1 through Section 1104.2.3.
- Refrigerant containing parts in systems exceeding 100 horsepower (74.6 kW) compressor drive power, except evaporators used for refrigeration or dehumidification, condensers used for heating, control and pressure-relief valves for either, and connecting piping, are located in a machinery room or outdoors. [ASHRAE 15:7.2.2]
Exception: Drying shall not be required in order to use recycled refrigerants where water is the refrigerant, is used as an absorbent, or is a deliberate additive. [ASHRAE 15:126.96.36.199]
Exception: Addition of a second refrigerant shall be permitted where specified by the equipment manufacturer to improve oil return at low temperatures. The refrigerant and amount added shall be in accordance with the manufacturer's instructions. [ASHRAE 15:188.8.131.52]
- Equipment containing Group A1 refrigerants shall be permitted to be supported by the same materials permitted for the building type.
- The use of approved vibration isolators specifically designed for the normal, wind, and seismic loads encountered, shall be permitted.
- Refrigerant evaporators, suspended overhead, shall be permitted to use portable means of access.
- Air filters, brine control or stop valves, fan motors or drives, and remotely de-energized electrical connections shall be permitted to be provided access by an unobstructed space not less than 30 inches (762 mm) in depth, width, and height. Where an access opening is immediately adjacent to these items and the equipment is capable of being serviced, repaired, and replaced from this opening, the dimensions shall be permitted to be reduced to 22 inches (559 mm) by 30 inches (762 mm) provided the largest piece of equipment is removed through the opening.
- Cooling equipment, using Group A1 refrigerants or brine, located in an attic or furred space shall be permitted to be provided an access by a minimum opening and passageway thereto of not less than 22 inches (559 mm) by 30 inches (762 mm).
- Cooling or refrigeration equipment, using Group A1 or B1 refrigerants or brine, located on a roof or on an exterior wall of a building, shall be permitted to be provided access as for furnaces in Section 304.3.
- Lighting fixtures shall be permitted to be omitted where the fixed lighting of the building will provide the required illumination.
- Equipment located on the roof or on the exterior walls of a building.
- A condensing unit in a room or space where the cubical content exceeds 1000 cubic feet per horsepower (ft3/hp) (37.95 m3/kW) of the unit.
- A condensing unit in a room or space that has permanent gravity ventilation having an area of 2 square feet (0.2 m2) or more to other rooms or openings exceeding 1000 ft3/hp (37.95 m3/kW).
Exception: Refrigerant ports in secure locations protected by walls or fencing and requiring key-access.
Exception: Direct and indirect-fired lithium bromide absorption systems using water as the refrigerant.
- Lithium bromide absorption systems using water as the refrigerant.
- Ammonia-water absorption unit systems installed outdoors, provided that the quantity of refrigerant in a single system does not exceed Table 1102.2 amounts and the discharge is shielded and dispersed.
- Systems containing less than 300 pounds (136.1 kg) of refrigerant R-123 and located in an approved exterior location.
- Systems containing less than 35 pounds (15.9 kg) of refrigerant R-717 and located in an approved exterior location.
- Alarm 1: 25 percent of the LFL, 50 percent of the IDLH, or the OEL, whichever is less.
- Alarm 2: 25 percent of the LFL or the vapor detector's upper detection limit, whichever is less. This alarm shall not be required for Group A1 and B1 refrigerants.
Alarms set at other refrigerant concentration levels shall be permitted in addition to those required by this section provided the meaning of each alarm is marked by signage or displays near the annunciators.
- Combustion air shall be ducted from outside the machinery room and sealed in such a manner as to prevent refrigerant leakage from entering the combustion chamber.
- A refrigerant detector, that is in accordance with Section 1106.4, shall be installed to automatically shut down the combustion process in the event of refrigerant leakage.
- Machinery rooms where carbon dioxide (R-744) or water (R-718) is the refrigerant.
- Machinery rooms where ammonia (R-717) is the refrigerant and internal combustion engines are used as the prime mover for the compressors. [ASHRAE 15:8.11.6]
- Momentary temperature excursions such as electrical contacts in A1 and B1 systems.
- Refrigeration machinery rooms used exclusively for direct-fired absorption equipment.
|Q||=||Air flow rate, cubic feet per minute.|
|G||=||Refrigerant mass in largest system, pounds.|
- The free-aperture cross section for the ventilation of a
machinery room shall be not less than as determined in
accordance with Equation 1107.3.
F = The free opening area, square feet. G = The mass of refrigerant in the largest system, any part
of which is located in the machinery room, pounds.
For SI units: 1 cubic foot per minute = 0.00047 m3/s, 1 pound = 0.453 kg
- The location of the gravity ventilation openings shall be based on the relative density of the refrigerant to air. [ASHRAE 15:5.11.5(a), (b)]
- Penetrations connecting the basement and the first floor.
- Penetrations connecting the top floor and a machinery penthouse or roof installation.
- Penetrations connecting adjacent floors served by the refrigeration system.
- Penetrations of a direct system where the refrigerant concentration does not exceed that listed in Table 1102.2 for the smallest occupied space through which the refrigerant piping passes.
- In other than industrial occupancies and where the refrigerant
concentration exceeds that listed in Table 1102.2
for the smallest occupied space, penetrations that connect
separate pieces of equipment that are in accordance with
one of the following:
- Enclosed by an approved gastight, fire-resistive duct or shaft with openings to those floors served by the refrigerating system.
- Located on the exterior wall of a building where vented to the outdoors or to the space served by the system and not used as an air shaft, closed court, or similar space. [ASHRAE 15:8.10.3]
- Tubing entirely within or tubing within 5 feet (1524 mm) of a refrigerant compressor where so located that it is not subject to external injury.
- Copper tubing serving a dwelling unit, where such tubing contains Group A1 refrigerant and is placed in locations not subject to damage from an external source.
Exception: Copper tubing enclosed in iron or steel piping conduit, molding, or raceway, provided there are no fittings or joints concealed therein.
- The suction inlet of a compressor, compressor unit, or condensing unit.
- The discharge of a compressor, compressor unit, or condensing unit.
- The outlet of a liquid receiver.
- Systems that have a refrigerant pumpout function capable of storing the refrigerant charge, or are equipped with the provisions for pumpout of the refrigerant.
- Self-contained systems. [ASHRAE 15:9.12.4]
- The suction inlet of a compressor, compressor unit, or condensing unit.
- The discharge outlet of a compressor, compressor unit, or condensing unit.
- The inlet of a liquid receiver, except for self-contained systems or where the receiver is an integral part of the condenser or condensing unit.
- The outlet of a liquid receiver.
- The inlets and outlets of condensers where more than one condenser is used in parallel in the systems.
Exception: Factory-sealed systems containing less than 22 pounds (9.9 kg) of Group A1 refrigerant listed by an approved agency. [ASHRAE 15:9.9.1]
Exception: On systems using nonpositive displacement compressors, the maximum setting of the pressure-limiting device shall not be required to be less than the design pressure of the highside of the system provided the pressure-relief device is located in the lowside, subject to lowside pressure, and there is a permanent (unvalved) relief path between the highside and the lowside of the system. [ASHRAE 15:9.9.2]
Exception: Hermetic refrigerant motor-compressors that are listed and have a displacement not more than 50 cubic feet per minute (1.42 m3/min).
The relief device(s) shall be sized based on compressor flow at the following conditions:
- For compressors in single-stage systems and high-stage compressors of other systems, the flow shall be calculated based on 50°F (10°C) saturated suction temperature at the compressor suction.
- For low-stage or booster compressors in compound systems, the compressors that are capable of running only where discharging to the suction of a high-stage compressor, the flow shall be calculated based on the saturated suction temperature equal to the design operating intermediate temperature.
- For low-stage compressors in cascade systems, the compressors that are located in the lower-temperature stage(s) of cascade systems, the flow shall be calculated based on the suction pressure being equal to the pressure setpoint of the pressure-relieving devices that protect the lowside of the stage against overpressure.
- The compressor is equipped with capacity regulation.
- Capacity regulation actuates to a flow at not less than 90 percent of the pressure-relief device setting.
- A pressure-limiting device is installed and set in accordance with the requirements of Section 1111.0. [ASHRAE 15:9.8]
- Relief valves shall not be required on heating coils that are designed to produce a temperature that will result in the saturation pressure of the refrigerant being less than the design pressure.
- A relief valve shall not be required on self-contained or
unit systems where the volume of the lowside of the
system, which is shut off by valves, is more than the specific volume of the refrigerant at critical conditions
of temperature and pressure, as determined in accordance
with Equation 1112.4.
V1 / [ W1 - (V2 - V1) / Vgt ] > Vgc (Equation 1112.4)Where:
V1 = Lowside volume, cubic foot (m3). V2 = Total volume of system, cubic foot (m3). W1 = Total weight of refrigerant in system, pounds (kg). Vgt = Specific volume of refrigerant vapor at 110°F (43°C),
cubic feet per pound (m3/kg).
Vgc = Specific volume at critical temperature and pressure,
cubic feet per pound (m3/kg). [ASHRAE 15:9.4.4]
Exception: Where fusible plugs are used on the highside, they shall be located above or below the liquid refrigerant level. [ASHRAE 15:9.4.8]
- The system contains less than 110 pounds (49.9 kg) of a Group A1 refrigerant.
- The system contains less than 6.6 pounds (2.99 kg) of a Group A2, B1 or B2 refrigerant.
- The system does not contain any quantity of a Group A3 or B3 refrigerant.
- The system is not required to be installed in a machinery room in accordance with Section 1106.0.
- The refrigerant concentration limits in Section 1104.0 are not exceeded. Refrigeration systems that do not comply with the above requirements shall comply with the requirements of Section 1112.10.2 through Section 1112.10.4. [ASHRAE 15:184.108.40.206]
- The point of vent discharge shall be located not less
than 15 feet (4572 mm) above the adjoining ground
Exception: Outdoor systems containing Group A1 refrigerant shall be permitted to discharge at any elevation where the point of discharge is located in an access-controlled area accessible to authorized personnel only.
- The point of vent discharge shall be located not less than 20 feet (6096 mm) from windows, building ventilation openings, pedestrian walkways, or building exits.
- For heavier-than-air refrigerants, the point of vent discharge shall be located not less than 20 feet (6096 mm) horizontally from below-grade walkways, entrances, pits or ramps where a release of the entire system charge into such a space would yield a concentration of refrigerant in excess of the RCL. The direct discharge of a relief vent into enclosed outdoor spaces, such as a courtyard with walls on all sides, shall not be permitted where a release of the entire system charge into such a space would yield a concentration of refrigerant in excess of the RCL. The volume for the refrigerant concentration calculation shall be determined using the gross area of the space and a height of 8.2 feet (2499 mm), regardless of the actual height of the enclosed space.
- The termination point of a vent discharge line shall be made in a manner that prevents discharged refrigerant from spraying directly onto personnel that are capable of being in the vicinity.
- The termination point of vent discharge line shall be made in a manner that prevents foreign material or debris from entering the discharge piping.
- Relief vent lines that terminate vertically upward and are subject to moisture entry shall be provided with a drip pocket having a length of not less than 24 inches (610 mm) and having the size of the vent discharge pipe. The drip pocket shall be installed to extend below the first change in vent pipe direction and shall be fitted with a valve or drain plug to permit removal of accumulated moisture. [ASHRAE 15:220.127.116.11]
- The pressure-relief valve that protects the higher-pressure vessel shall be selected to deliver capacity in accordance with Section 1113.5 without exceeding the maximum allowable working pressure of the higher-pressure vessel accounting for the change in mass flow capacity due to the elevated backpressure.
- The capacity of the pressure-relief valve protecting the part of the system receiving a discharge from a pressure-relief valve protecting a higher-pressure vessel shall be not less than the sum of the capacity required in Section 1113.5 plus the mass How capacity of the pressure-relief valve discharging into that part of the system.
- The design pressure of the body of the relief valve used on the higher-pressure vessel shall be rated for operation at the design pressure of the higher-pressure vessel in both pressure-containing areas of the valve. [ASHRAE 15:18.104.22.168]
- The pressure-relief device set pressure shall not exceed 15 psig (103 kPa).
- The floor drain shall be sized to handle the flow rate from a single broken tube in a refrigerant-containing heat exchanger.
- The Authority Having Jurisdiction finds it acceptable that the working fluid, corrosion inhibitor, and other additives used in this type of refrigeration system are permitted to infrequently be discharged to the sewer system, or a catch tank that is sized to handle the expected discharge shall be installed and equipped with a normally closed drain valve and an overflow line to drain. [ASHRAE 15:22.214.171.124.1]
SEA LEVEL, FEET
|POUNDS PER SQUARE
INCH, ABSOLUTE (Pa)
|L||=||Equivalent length of discharge piping, feet.|
|Cr||=||Rated capacity as stamped on the relief device in
pounds per minute (lb/min), or in SCFM multiplied
by 0.0764, or as calculated in Section
1112.13 for a rupture member or fusible plug, or
as adjusted for reduced capacity due to piping in
accordance with the manufacturer of the device,
or as adjusted for reduced capacity due to piping
as estimated by an approved method.
|f||=||Moody friction factor in fully turbulent flow.|
|d||=||Inside diameter of pipe or tube, inches.|
|P2||=||Absolute pressure at outlet of discharge piping,
|P0||=||Allowed back pressure (absolute) at the outlet
of pressure relief device, (psia).
Unless the maximum allowable back pressure (P0) is specified by the relief valve manufacturer, the following maximum allowable back pressure values shall be used for P0, where P is the set pressure and Pa is atmospheric pressure at the nominal elevation of the installation (see Table 1112.11.3):
For conventional relief valves: 15 percent of set pressure:
For balanced relief valves: 25 percent of set pressure:
For rupture disks alone: fusible plugs, and pilot operated relief devices, 50 percent of set pressure:
For fusible plugs, P shall be the saturated absolute pressure for the stamped temperature melting point of the fusible plug or the critical pressure of the refrigerant used, whichever is smaller. [ASHRAE 15:126.96.36.199.1, 188.8.131.52.2]
|C||=||Rated discharge capacity of air, pounds per minute.|
|d||=||Smallest internal diameter of the inlet pipe, retaining
flanges, fusible plug, or rupture member; inches.
For rupture members:
For fusible plugs:
|P1||=||Absolute saturation pressure, corresponding to the
stamped temperature melting point of the fusible plug or
the critical pressure of the refrigerant used, whichever is
smaller, pound-force per square inch atmosphere, psia.
For SI units: 1 inch = 25.4 mm, 1 pound-force per square inch = 6.8947 kPa, 1 pound per minute = 0.00756 kg/s
|C||=||Minimum required discharge capacity of the relief device
expressed as mass flow of air, pounds per minute (kg/s).
|D||=||Outside diameter of vessel, feet (m).|
|L||=||Length of vessel, feet (m).|
|f||=||Factor dependent upon type of refrigerant from Table
Where combustible materials are used within 20 ft (6096 mm) of a pressure vessel, the value off shall be multiply by 2.5. Equation 1113.5 is based on fire conditions, other heat sources shall be calculated separately. Where one pressure-relief device or fusible plug is used to protect more than one pressure vessel, the required capacity shall be the sum of the capacity required for every pressure vessel. [ASHRAE 15:9.7.5]
|REFRIGERANT||VALUE OF f|
|Where used on the lowside of a limited-charge cascade system:|
|R-23, R-170, R-744, R-1150, R-508A, R-508B||1|
|R-13, R-13B1, R-503||2|
|R-11, R-32, R-113, R-123, R-142b, R-152a, R-290, R-600, R-600a,
|R-12, R-22, R-114, R-124, R-134a, R-401A, R-401B, R-401C, R-
405A, R-406A, R-407C, R-407D, R-407E, R-409A, R-409B, R-
411A, R-411B, R-411C, R-412A, R-414A, R-414B, R-500, R-1270
|R-143a, R-402B, R-403A, R-407A, R408A, R-413A||2|
|R-115, R-402A, R-403B, R-404A, R-407B, R-410A, R-410B, R-
502, R-507A, R-509A
- The relief valves are located on the lowside of the system.
- The vessel is provided with shutoff valves designed to allow pump down of the refrigerant charge of the pressure vessel.
- Other pressure vessels in the system are separately protected in accordance with Section 1113.1. [ASHRAE 15:184.108.40.206]
- Ammonia absorption systems serving a single dwelling unit.
- Where the Authority Having Jurisdiction determines upon review of a rational engineering analysis that fire, health, or environmental hazards will not result from the proposed atmospheric release.
- Lithium bromide absorption system using water as the refrigerant.
- Name of contractor installing the equipment.
- Name and number designation of refrigerant in system.
- Pounds of refrigerant in system.
Exception: Relief valves for systems with design pressures of 15 pounds-force per square inch gauge (psig) (103 kPa) or less shall be marked by the manufacturer with the pressure-setting capacity. [ASHRAE 15:9.6.1]
- Mixtures of dry nitrogen, inert gases, nonflammable refrigerants permitted for factory tests.
- Mixtures of dry nitrogen, inert gases, or a combination of them with flammable refrigerants in concentrations not exceeding the lesser of a refrigerant weight fraction (mass fraction) of 5 percent or 25 percent of the LFL shall be permitted for factory tests.
- Compressed air without added refrigerant shall be permitted for factory tests provided the system is subsequently evacuated to less than 0.039 inch of mercury (0.132 kPa) before charging with refrigerant. The required evacuation level is atmospheric pressure for systems using R-718 (water) or R-744 (carbon dioxide) as the refrigerant. [ASHRAE 15:220.127.116.11]
- Compressors, condensers, evaporators, coded pressure vessels, safety devices, pressure gauges, control mechanisms, and systems that are factory tested.
- Refrigeration systems containing Group R-22, not exceeding 5 tons of refrigeration capacity (18 kW), and field-piped using approved, factory-charged line sets shall be permitted to be proved tight by observing retention of pressure on a set of charging gauges and soaping connections while the system is operating.
|REFRIGERANT NUMBER||HIGHSIDE WATER COOLED||HIGHSIDE AIR COOLED||LOWSIDE|
* Special design required; test pressures typically exceed 1000 psig (6895 kPa).
- Mixtures of dry nitrogen, inert gases, or a combination of them with nonflammable refrigerant in concentrations of a refrigerant weight fraction (mass fraction) not exceeding 5 percent shall be permitted for tests.
- Mixtures of dry nitrogen, inert gases, or a combination of them with flammable refrigerants in concentrations not exceeding the lower of a refrigerant weight fraction (mass fraction) of 5 percent or 25 percent of the LFL shall be permitted for tests.
- Compressed air without added refrigerants shall be permitted for tests, provided the system is subsequently evacuated to less than 1000 microns (0.1333 kPa) before charging with refrigerant. The required evacuation level is atmospheric pressure for systems using R-718 (water) or R-744 (carbon dioxide) as the refrigerant.
- Systems erected on the premises using Group A1 refrigerant and with copper tubing not exceeding 0.62 of an inch (15.7 mm) outside diameter shall be tested by means of the refrigerant charged into the system at the saturated vapor pressure of the refrigerant at not less than 68°F (20°C). [ASHRAE 15:10.1.2]
- Be listed individually or as part of an assembly.
- Marked directly on the vessel or on a nameplate attached to the vessel in accordance with ASME BPVC Section VIII.
- Where requested by the Authority Having Jurisdiction, the manufacturer shall provide documentation to confirm that the vessel design, fabrication, and testing requirements are in accordance with ASME BPVC Section VIII.
Pressure vessels having inside dimensions of 6 inches (152 mm) or less shall be protected by either a pressure-relief device or a fusible plug. [ASHRAE 15:18.104.22.168]