ANSI/IIAR Standard Interpretations

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INTERPRETATION: IIAR SC 2024-1, IIAR 2-2021 and IIAR CO2. Capacity Factors and Engine-Driven Compressors
SUBJECT: Relief Valve Capacity Factors when Engine Drive Compressors are Present
DATE ISSUED: January 10, 2024

INTERPRETATION: IIAR SC 2024-2, IIAR 2-2021 - Plate and Shell HXR Strength and Testing Requirements
SUBJECT: Plate and shell heat exchanger strength and testing requirements
DATE ISSUED: January 10, 2024

INTERPRETATION: IIAR SC 2022-1, IIAR 2-2021 and IIAR 2-2014 – Valve Flanges 
SUBJECT: Compliance Requirements for Valve Flanges not meeting dimensional requirements of B16.5 
DATE ISSUED: October 24, 2022


INTERPRETATION: IIAR SC 2021-4, IIAR 2-2021, Eyewash/Flushing Requirements in Areas Other Than Machinery Rooms
SUBJECT: Water flow rate and duration of supplemental equipment
DATE ISSUED: November 23, 2021

QUESTION: Does a 0.4 GPM drench hose satisfy the requirements for supplemental flushing equipment? 

INTERPRETATION: IIAR SC 2021-5, IIAR 2-2021 – Piping Design Pressure
SUBJECT: Design Pressure for Piping
DATE ISSUED: November 5, 2021

QUESTION: Is it the IIAR’s position that piping connected to a pressure vessel or other component have a design pressure that is equal to or greater than the nameplate design pressure or the pressure vessel or other component?

INTERPRETATION: IIAR SC 2021-1, IIAR 9 – Spark Resistant Construction of Existing Exhaust Fans
SUBJECT: Applicability of non-spark resistant fan construction to IIAR 9
DATE ISSUED: September 16, 2021

QUESTION: If an existing facility uses the provisions in IIAR 2-2021, Section 6.14.3 and has non-emergency exhaust fans that are not constructed like emergency exhaust fans, but will shut off when an ammonia concentration of 150 ppm is detected, will the facility be in violation of IIAR 9 that requires all exhaust fans in a machinery room, regardless of function, to have non-sparking blades?  


INTERPRETATION: IIAR SC 2021-2, IIAR 2 Machinery Room Door Louvers
SUBJECT: Machinery Room Door Louvers
DATE ISSUED: May 13, 2021

QUESTION: Are these requirements intended to prohibit the installation of a louver in the door itself? There seems to be no discernable difference between having a louver in door and having a louver in a wall right next to the door.  


INTERPRETATION: IIAR SC 2021-3, IIAR 5, Evacuation and Dehydration
SUBJECT: Evacuation and Dehydration of Industrial Ammonia Refrigeration Systems
DATE ISSUED: May 13, 2021

QUESTION: There was a change in the requirements for evacuation and dehydration from IIAR 5-2013 to IIAR 5-2019.  The change is significant.  What was the basis of the change?  Is the proposed level of evacuation truly necessary to insure a properly evacuated system? Why are the evacuation and dehydration levels no longer separate values? And why is dehydration now mandatory when it was formerly required only when water removal was necessary?   


INTERPRETATION: IIAR SC 2020-2
SUBJECT: Replacement Frequency of Internally Relieving Pressure-Relief Valves
DATE ISSUED: August 24, 2020

QUESTION: Historically, liquid pressure-relief valves or vapor pressure-relief valves that relieve into another part of the closed-circuit refrigeration system (internally-relieved) have not been subject to periodic replacement (see IIAR Bulletin 110), requiring attention only when there are indications of a failure.  Because these valves are not subject to internal corrosion, they are also less likely to fail than those relieving to atmosphere. And even if they do fail internally, the consequences are not severe because the discharge is back into the system. Evidence and research guide the requirements for testing and replacement of atmospheric pressure-relief valves, but similar evidence and research does not exist for pressure-relief valves that discharge internal to the system. IIAR 6-2019, Section 13.1.4, essentially changed the ITM requirements for internally relieved hydrostatic or vapor pressure-relief valves, to rely on manufacturer’s recommendations only, who may have unjustifiable reasons to recommend replacement at frequencies greater than necessary. Does IIAR know of any reason to specify replacement of internally relieved liquid or vapor pressure-relief valves when there is no indication of failure or pending failure? 


INTERPRETATION: IIAR SC 2020-1
SUBJECT: Use of Gravity Intake for Makeup Air
DATE ISSUED: May 5, 2020

QUESTION 1: Would Gravity Intake units be acceptable as the only make up air for a machinery room?
QUESTION 2: What distance would the exhaust fan need to be from a gravity intake in a machinery room in order to avoid short circuit of exhaust air?
QUESTION 3: Does a smoke test or any other test need to be conducted to prove air flow coverage in a machinery room?

 

INTERPRETATION: IIAR SC 2019-3
SUBJECT: Tee Diffusers on Relief Headers
DATE ISSUED: Oct. 22, 2019

QUESTION: Is a horizontal discharge through a tee, with no vertical upward component, sufficient to meet the intent of the standard, or must all discharges to atmosphere have a vertical-upward component (i.e. at some angle above horizontal)?

INTERPRETATION: IIAR SC 2019-2
SUBJECT: Leak Testing After Routine Maintenance
DATE ISSUED: Oct. 22, 2019

QUESTION 1: Please clarify the appropriate leak test pressures for leak testing after routine maintenance activities that do not involve repair, modification or expansion of the system. Would using the design operating pressure be sufficient to be compliant with “a pressure specified in the engineering design” for such maintenance activities?
QUESTION 2: Please also clarify the time frame required for proving system tightness.

INTERPRETATION: IIAR SC 2019-1
 SUBJECT: Evaporators with Surge Drums in Areas Other than a Machinery Room
DATE ISSUED: May 8, 2019

QUESTION:  Are there any exclusions to the types of evaporator that can be located in areas other than a machinery room?

INTERPRETATION: IIAR SC 2018-2
SUBJECT: ANSI / IIAR 2-2014 Section 6.14.1
DATE ISSUED: August 27, 2018

QUESTION:  Section 6.14.1 of IIAR-2-2014 requires occupancy ventilation; Appendix 4.A Explanatory material allows natural ventilation to meet the requirements. Is natural ventilation an acceptable solution for occupancy in all instances or only for those systems when a machine room can be naturally ventilated?

INTERPRETATION: IIAR SC 2018-1
SUBJECT: ANSI / IIAR 2-2014 Flexible Connectors for Relief Piping
DATE ISSUED: January 11th, 2018

QUESTION:  Are flexible hose connections sufficient to serve as connective piping between relief valve outlets and the associated relief discharge header piping?

INTERPRETATION: IIAR SC 2016-1
SUBJECT: IIAR Bulletin 110, Section 6.6.3
DATE ISSUED: March 10, 2017

QUESTION: Does the 5-year replacement interval begin upon...

INTERPRETATION: IIAR SC 2016-2
SUBJECT: ANSI / IIAR 2-2014, section 12.2.6
DATE ISSUED: March 10, 2017

QUESTION: Please provide formal interpretation of the committee's intent for this provision to make it clear...

INTERPRETATION: IIAR SC 2016-3
SUBJECT: ANSI / IIAR 2-2014, Chapter 14 and other related chapters and sections
DATE ISSUED: March 10, 2017

QUESTION: Questions pertain to packaged systems that require a machinery room in accordance with Chapter 4.

INTERPRETATION: IIAR SC 2016-4
SUBJECT: ANSI / IIAR 2-2014, Section 5.2.2 Ammonia Purity Table
DATE ISSUED: March 10, 2017

QUESTION: The purity table published in the IIAR-2-2014, section 5.2.2, appears to be overly restrictive and not representative of the refrigerant grade ...

INTERPRETATION:  IIAR SC 2013-1
SUBJECT: ANSI / IIAR 2-2008, Section 6.2.2.1
DATE ISSUED: April 5, 2013

QUESTION: Does this mean the relief valve mounted on a screw compressor package consisting of an oil separator...

INTERPRETATION:  IIAR SC 2012-1 - Revised November 4, 2016
SUBJECT: ANSI / IIAR-2, 2008 ADDENDUM A, Section 11.3.3
DATE ISSUED: JANUARY 6, 2012

QUESTION: Section 11.3.3 was revised to allow an exception for ASTM A120, A53/A120, or A53 Type F to be used as relief piping...

INTERPRETATION: SRC 2011-2 - Revised November 4, 2016
SUBJECT: ANSI / IIAR-2, 2008 ADDENDUM A, Section 3
DATE ISSUED: July 19, 2011

QUESTION: It is common that some process refrigeration equipment that is located in production rooms are often equipped with pumps...

INTERPRETATION: IIAR SRC 2011-1
SUBJECT: ANSI/IIAR-2, 2008 ADDENDUM A, Section 10.3.1.2
DATE ISSUED: APRIL 26, 2011

QUESTION: Section 10.3.1.2 states “Valve gasket materials shall match valve manufacturer’s specifications, be compatible...

INTERPRETATION: IIAR SRC 2004-1
SUBJECT: ANSI/IIAR 2-1999 Section 6.2.3.6
DATE ISSUED: OCTOBER 7, 2004

QUESTION: Section 6.2.3.6 states that a machinery room in a basement has to have a...

INTERPRETATION: IIAR SRC 2001-1
SUBJECT: ANSI/IIAR 2-1999, SECTION 5.15
DATE ISSUED: AUGUST 23, 2001

QUESTION: In the city of Chicago, the installation of a “Fireman’s Dump” is required...

INTERPRETATION: IIAR SRC 2000-2
SUBJECT: IIAR 2-1999
DATE ISSUED: MARCH 31, 2000

QUESTION: Does IIAR 2-1999 forbid the use of duplicate nameplates on...

INTERPRETATION: IIAR SRC 2000-1
SUBJECT: IIAR 2-1999
DATE ISSUED: MARCH 23, 2000

QUESTION: In IIAR 2-1999, Paragraph 5.17.2, Ultimate Strength Testing, states that “every pressure...

 

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