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Basic differences between AFQRJOS Issue 25 v Issue 26 may please be explained.
 
Answers
09/11/2012 A: Sridhar Balakrishnan, Bharat Oman Refineries Limited , laksrid@yahoo.com
The differences are
Number one
Issue 25 - 5th May 2011 - is relating to British MoD DEF STAN 91-91/Issue 7, date 18 th February 2011, Jet A-1 and ASTM D 1655 -10, Jet A-1 .
Issue 26 - 4th May 2012 - is relating to British MoD DEF STAN 91-91/Issue 7, Amendent 1 , date 16 th December 2011, Jet A-1 and ASTM D 1655 -11b, Jet A-1.
Number two
Note 4 ( Main table notes )
Issue 25 - 5th May 2011 - has mentioned about a) up to 50 % of Synthetic Paraffinic Kerosine certified as meeting the requirements of ASTM D 7566 Annex A1.
Issue 26 - 4th May 2012 - has mentioned two generic components a) 50 % of Synthetic Paraffinic Kerosine certified as meeting the requirements of ASTM D 7566 Annex A1. And b) upto 50 % of Hydrogenated Esters and Fatty Acids certified as meeting the requirements of ASTM D 7566 A2 .
Number three
Note 8 ( Main table notes )
Issue 25 - 5th May 2011 - The need to report the %v/v of non hydroprocessed, hydroprocessed, severely hydroprocessed and synthetic components ( including “nil “ or “100%” as appropriate ) on refinery Certificates of Quality for Jet A-1 to Check list derives from DEF STAN 91-91/7 . Each refinery component used in the make up of the batch shall be reported on certificate of quality as a percentage by volume of the total fuel in the batch. Severely hydroprocessed components are defined as those petroleum derived hydrocarbons that have been subjected to a hydrogen partial pressure of greater than 7000 kPa ( 70 bar or 1015 pSi) during manufacture.
Issue 26 - 4th May 2012 - The need to report the %v/v of non hydroprocessed, mildly hydroprocessed, severely hydroprocessed and synthetic components (including “nil “ “50 % “ or “100%” as appropriate ) on refinery Certificates of Quality for Jet A-1 toCheck list derives from DEF STAN 91-91/7 Amendent 1. Each refinery component used in the make up of the batch shall be reported on certificate of quality as a percentage by volume of the total fuel in the batch . Mildly hydroprocesses components are defined as those petroleum derived hydrocarbons that have been subjected to a hydrogen partial pressure of less than 7000 kPa ( 70 bar or 1015 pSi) during manufacture. Severly hydroprocessed components are defined as those petroleum derived hydrocarbons that have been subjected to a hydrogen partial pressure of greater than 7000 kPa ( 70 bar or 1015 pSi) during manufacture. The total of non –hydroprocessed plus mildly hydroprocessed plus severly hydroprocessed plus synthetic components shall equal 100% .
Number Four
Note 14 ( Main table notes )
Issue 25 - 5th May 2011 - Examination of the heater tube to determine the Visual Tube Rating using the Visual Tuberator shall be carried out within 120 mts. of the completion of the test. It is Visual Method that should be reported. Attention is drawn to the Note 15 in DEF STAN 91-91/7 which stresses that only approved heater tubes shall be used and lists JFTOT tubes from PAC- Alcor as being technically suitable.
Issue 26 - 4th May 2012 - Examination of the heater tube to determine the Visual Tube Rating using the Visual Tuberator shall be carried out within 120 mts. of the completion of the test. It is Visual Method that should be reported. Attention is drawn to the Note 15 in DEF STAN 91-91/7 Amendent 1 which stresses that not only approved heater tubes shall be used and lists heater tubes from PAC- Alcor and Falex as being technically suitable.