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Comparison of Piping Inspection Requirements in Refrigeration Industry |
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Code |
Component Description |
Inspection |
Remediation |
Inspection Frequency |
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IIAR 109 (1997) |
Uninsulated Pipe (4.7.4)
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Examine for corrosion |
Clean pipe down to bare metal and paint with rust preventative paint.
“Badly corroded pipe should be replaced.” (4.7.4) |
– Annual ammonia safety check (5.2)
– Thorough inspection every 5 years (5.3)
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Insulated Pipe (4.7.5) |
If sign of vapor barrier failure, remove insulation and inspect pipe
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IIAR 110 (1993) Including (2004 addenda) |
Uninsulated Pipe (6.7.1) |
External surface appearance should be regularly checked for deterioration. |
– Slight corrosion; clean and reinstate protective finish.
– Loss of metal >10%; if wall thinning is confirmed, seek expert advice. |
At least annually. |
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Insulated Pipe (6.7.2) |
Surface of insulation should be regularly checked for deterioration |
– Mechanical damage to insulation; fix immediately. – Insulation in poor condition to be removed and pipe beneath inspected. Replace, re-insulate as necessary. |
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NBIC-23 |
Piping Systems |
Ensure there is: – Provision for expansion
– Provision for adequate support
– No evidence of leakage
– Proper alignment of connections
– Proper rating for service conditions
– No evidence of corrosion, erosion, cracking or other detrimental conditions |
Any defects or deficiencies in the condition, operating and maintenance practices of the piping system equipment should be discussed with the owner or user…and recommendations made for correction. |
None specified |
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ASME/ANSI B31.5 |
Visual Inspection (536.4.1) |
Performed, as necessary, during the fabrication and erection of piping components to verify design and procedure specifications are met. |
Shall be as stated in Chapter V of the B31.5; 527 for welded joints, 528 for brazed and soldered joints, and 535 for other mechanical joints and assembly of hanger. |
At time of manufacture, construction and erection. |
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Additional examination for A3 and B3 refrigerants |
-Not less than 5% of circumferential butt and miter groove welds fully inspected by radiography.
-Not less than 5% of brazed joints examined by in-process examination. |
Samples to be selected to ensure the work of each welder/fitter making joints. |
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API 570 |
Class 1 piping |
-Thickness measurements at inspection points at frequency listed for piping class. Used to determine corrosion rate and remaining life.
-External visual examination, including for corrosion under insulation (CUI).
-Appropriate % of pipe inspected for CUI under 1. Damaged insulation and 2. Suspect insulation |
Repair or replace following the principals of ASME B31.3 or the code to which the piping system was built and in complete accordance with API 570. |
Thickness-5 yr. Ext. Visual-5 yr. 1. 75% 2. 50% |
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Class 2 piping |
Thickness-10 yr. Ext. Visual-5 yr. 1. 50% 2. 33% |
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Class 3 piping |
Thickness-10 yr. Ext. Visual-10 yr. 1. 25% 2. 10% |
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Source: IRC Mechanical Integrity Workshop |
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