As of yesterday (12/15/2017), the state of Ohio has a new fire code, which just happens to be a revised version of the 2015 International Fire Code. As I have been writing about this year, this revised code could have an impact on a number of businesses/industries. For example, ammonia refrigeration processes that are built from this day on will NO LONGER be permitted to discharge their relief valves (RV) to the atmosphere, without first getting an “engineering analysis” (done per the code) to show that there would be no fire, health or environmental hazard and then convincing the State Fire Marshal so he/she would grant the exception. Here is a breakdown of the new requirements:
NOTE 1: the blue font is NOT a hyperlink, but when you place your cursor over the blue font you should see a small box with the requirements pop up. This is to make it easier to link all the requirements to your design basis.
NOTE 2: I have changed the structure of how the code is laid out to make it easier to follow.
606.12 Discharge and termination of pressure relief and purge systems
Pressure relief devices, fusible plugs and purge systems discharging to the atmosphere from refrigeration systems containing more than 6.6 pounds (3 kg) of flammable, toxic or highly toxic refrigerants or ammonia shall comply with paragraphs 606.12.3 to 606.12.5 of this rule.
606.12.1 Standards
Refrigeration systems and the buildings in which such systems are installed shall be in accordance with ASHRAE 15 as listed in rule 1301:7-7-80 of the Administrative Code.
606.12.1.1 Ammonia refrigeration
Refrigeration systems using ammonia refrigerant and the buildings in which such systems are installed shall comply with IIAR-2 as listed in rule 1301:7-7-80 of the Administrative Code for system design and installation and IIAR-7 as listed in rule 1301:7-7-80 of the Administrative Code for operating procedures.
606.12.2 Fusible plugs and rupture members
Discharge piping and devices connected to the discharge side of a fusible plug or rupture member shall have provisions to prevent plugging the pipe in the event the fusible plug or rupture member functions.
606.12.3 Flammable refrigerants
Systems containing more than 6.6 pounds (3 kg) of flammable refrigerants having a density equal to or greater than the density of air shall discharge vapor to the atmosphere only through an approved treatment system in accordance with paragraph (606.12.6) of this rule or a flaring system in accordance with paragraph (606.12.7) of this rule.
Systems containing more than 6.6 pounds (3 kg) of flammable refrigerants having a density of less than the density of air shall be permitted to discharge vapor to the atmosphere provided that the point of discharge is located outside of the structure at not less than 15 feet (4572 mm) above the adjoining grade level and not less than 20 feet (6096 mm) from any window, ventilation opening or exit.
606.12.4 Toxic and highly toxic refrigerants
Systems containing more than 6.6 pounds (3 kg) of toxic or highly toxic refrigerants shall discharge vapor to the atmosphere only through an approved treatment system in accordance with paragraph (606.12.6) of this rule or a flaring system in accordance with paragraph (606.12.7) of this rule.
606.12.5 Ammonia refrigerant
Systems containing more than 6.6 pounds (3 kg) of ammonia refrigerant shall discharge vapor to the atmosphere in accordance with one of the following methods:
(i) Directly to atmosphere where the fire code official determines, on review of an engineering analysis prepared in accordance with paragraph (104.7.2) of rule 1301:7-7-01 of the Administrative Code, that a fire, health or environmental hazard would not result from atmospheric discharge of ammonia.
(ii) Through an approved treatment system in accordance with paragraph (606.12.6) of this rule.
(iii) Through a flaring system in accordance with paragraph (606.12.7) of this rule.
(iv) Through an approved ammonia diffusion system in accordance with paragraph (606.12.8) of this rule.
(v) By other approved means.
Exception: Ammonia/water absorption systems containing less than 22 pounds (10 kg) of ammonia and for which the ammonia circuit is located entirely outdoors.
606.12.6 Treatment systems
Treatment systems shall be designed to reduce the allowable discharge concentration of the refrigerant gas to not more than 50 percent of the IDLH at the point of exhaust.
Treatment systems shall be in accordance with rule 1301:7-7-60 of the Administrative Code.
606.12.7 Flaring systems
Flaring systems for incineration of flammable refrigerants shall be designed to incinerate the entire discharge.
The products of refrigerant incineration shall not pose health or environmental hazards.
Incineration shall be automatic upon initiation of discharge, shall be designed to prevent blowback and shall not expose structures or materials to threat of fire.
Standby fuel, such as LP gas, and standby power shall have the capacity to operate for one and one-half the required time for complete incineration of refrigerant in the system.
Standby electrical power, where required to complete the incineration process, shall be in accordance with paragraph (D)(604) of this rule.
606.12.8 Ammonia diffusion systems
Ammonia diffusion systems shall include a tank containing 1 gallon of water for each pound of ammonia (48.3 L of water for each 1 kg of ammonia) that will be released in 1 hour from the largest relief device connected to the discharge pipe.
The water shall be prevented from freezing.
The discharge pipe from the pressure relief device shall distribute ammonia in the bottom of the tank, but no lower than 33 feet (10 058 mm) below the maximum liquid level.
The tank shall contain the volume of water and ammonia without overflowing.
606.13 Discharge location for refrigeration machinery room ventilation
Exhaust from mechanical ventilation systems serving refrigeration machinery rooms containing flammable, toxic or highly toxic refrigerants, other than ammonia, capable of exceeding 25 percent of the LFL or 50 percent of the IDLH shall be equipped with approved treatment systems to reduce the discharge concentrations to those values or lower.
606.14 Notification of refrigerant discharges
The fire code official shall be notified immediately when a discharge becomes reportable under state, federal or local regulations in accordance with paragraph 5003.3.1 of rule 1301:7-7-50 of the Administrative Code.
606.15 Records
A record of refrigerant quantities brought into and removed from the premises shall be maintained.
606.16 Electrical equipment
Where refrigerants of Groups A2, A3, B2, and B3, as defined in the mechanical code as listed in rule 1301:7-7-80 of the Administrative Code, are used, refrigeration machinery rooms shall conform to the CLASS I, DIVISION 2 HAZARDOUS LOCATION classification requirements of NFPA 70 as listed in rule 1301:7-7-80 of the Administrative Code.
Exception: Ammonia machinery rooms that are provided with ventilation in accordance with section 1106.3 of the mechanical code as listed in rule 1301:7-7-80 of the Administrative Code.