1、 WORLDWIDE ENGINEERING STANDARDS Test Procedure GMW14292 Determination of Deposits in the Fuel System Copyright 2012 General Motors Company All Rights Reserved September 2012 Originating Department: North American Engineering Standards Page 1 of 3 1 Scope Note: Nothing in this standard supercedes ap
2、plicable laws and regulations. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Purpose. This test procedure describes the determination of substances from fuel hoses and other elastomeric parts of the fuel system which could f
3、orm deposits on copper and copper alloys. 1.2 Foreword. Not applicable. 1.3 Applicability. All gasoline fuel systems. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ISO 4794 2.2 GM Standards/Specifications. GMW1
4、4914 3 Resources 3.1 Facilities. Not applicable. 3.2 Equipment. 3.2.1 Erlenmeyer flask 250 ml. 3.2.2 Round-bottom flask 250 ml. 3.2.3 Folded filter diameter 125 mm. 3.2.4 Glass funnel. 3.2.5 Glass beads diameter 1.5 mm. 3.2.6 Copper chips. 3.2.7 Methanol modified test fuel to GMW14914, Table 1: Test
5、 Fuel for Gasoline Application, GM Europe (GME). 3.2.8 Glass filter crucible Number 4 according to ISO 4794, porosity 10 m-6 to 16 m-6. 3.2.9 Balance with an accuracy of 0.1 mg. 3.2.10 Water jet pump. 3.2.11 Desiccator. 3.3 Test Vehicle/Test Piece. 3.3.1 The elastomers to be tested shall be cut into
6、 small cubes with 2 mm to 3 mm width. For one test, approximately 20 g of elastomer are required. 3.3.2 For initial sample approval and arbitration purposes at least three (3) tests should be performed. For routine quality control purpose, one test should be performed. 3.4 Test Time. Not applicable.
7、 3.5 Test Required Information. Not applicable. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14292 Copyright 2012 General Motors Compa
8、ny All Rights Reserved September 2012 Page 2 of 3 3.6 Personnel/Skills. Not applicable. 4 Procedure 4.1 Preparation. For initial sample approval and arbitration purposes, the minimum time period between manufacturing and testing of elastomers shall be seven (7) days. For routine quality control purp
9、oses, the time period shall be a minimum of 72 h. Before testing, the test pieces shall be stored at a temperature of +23 C 5 C for at least 8 h and shall be free from strain during this period. 4.2 Conditions. 4.2.1 Environmental Conditions. Not applicable. 4.2.2 Test Conditions. Deviations from th
10、e requirements of this standard shall have been agreed upon. Such requirements shall be specified on component drawings, test certificates, reports, etc. 4.3 Instructions. 4.3.1 Before testing, all glassware shall be rinsed with test fuel per GMW14914. 4.3.2 Twenty (20) g of the test pieces, 10 g of
11、 the copper chips, and 100 ml test fuel to GMW14914 shall be filled together with two (2) glass beads into the round bottom flask and shall be boiled 1 h 0.1 h on reflux. 4.3.3 After 1 h 0.1 h of cooling down, the fuel shall be filtered through the folded filter into the Erlenmeyer flask. 4.3.4 The
12、filtrate shall be stored in the closed Erlenmeyer flask in darkness for 48 h + 0 h -2 h at +23 C 5 C. 5 Data 5.1 Calculations. Not applicable. 5.2 Interpretation of Results. 5.2.1 After 48 h + 0 h -2 h storage in darkness, the fluid shall be visually inspected for cloudy or crystalline deposits. Col
13、or changes of the fuel are negligible. In the presence of deposits, see 5.2.2.1 through 5.2.2.4.2. 5.2.2 In the presence of deposits, the following procedure shall be performed. 5.2.2.1 The glass filter crucible shall be rinsed with test fuel to GMW14914 and shall be dried for at least 4 h at + 50 C
14、. After cooling down for 1 h 0.1 h in a desiccator, the weight of the glass filter crucible shall be determined with an accuracy of 0.1 mg. The deposits from the Erlenmeyer flask shall be completely transferred to the glass filter crucible, and the fuel shall be simultaneously sucked off using a wat
15、er jet pump. 5.2.2.2 The glass filter crucible shall be dried for at least 4 h at + 50 C. After cooling down for 1 h 0.1 h in a desiccator, the weight of the glass filter crucible shall be determined with an accuracy of 0.1 mg and the amount of deposits shall be calculated. 5.2.2.3 Observe the color
16、 of the deposits. Deposits of brown color shall be determined by Infrared Spectroscopy (IR Spectroscopy). In the presence of dimethyldithiocarbamate, the test is not fulfilled even if the amount is 20 mg. (Dimethyldithiocarbamate electrically insulates the fuel pump.) 5.2.2.4 Results. 5.2.2.4.1 Test
17、 is fulfilled: In case of no deposits in the fuel. In case of deposits, when the amount is 20 mg per 20 g elastomer portion and deposits are in light color. 5.2.2.4.2 Test is Not Fulfilled: In case of any deposits with an amount of 20 mg per 20 g elastomer portion, independent of color or nature of
18、deposits. In case of the presence of dimethyldithiocarbamate, irrespective of the amount of deposits. 5.3 Test Documentation. Report the results of this test procedure in a test report. Include measurements and observations regarding deposits in the filtrate including composition and amounts above 2
19、0 mg. Also report the amount of dimethyldithiocarbamate, even if it is 20 mg. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14292 Copyr
20、ight 2012 General Motors Company All Rights Reserved September 2012 Page 3 of 3 6 Safety This standard may involve hazardous materials, operations, and equipment. This standard does not propose to address all the safety problems associated with its use. It is the responsibility of the user of this s
21、tandard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 7 Notes 7.1 Glossary. Erlenmeyer Flask: Also known as a conical flask is a widely used type of laboratory flask which features a flat bottom, a conical body, and a cyl
22、indrical neck. 7.2 Acronyms, Abbreviations, and Symbols. GME General Motors Europe IR Spectroscopy Infrared Spectroscopy 8 Coding System This standard shall be referenced in other documents, drawings, etc., as follows: Test to GMW14292 9 Release and Revisions This standard was originated in Septembe
23、r 2005. It was first approved by the Global Elastomers Team in December 2006. It was first published in August 2007. Issue Publication Date Description (Organization) 1 AUG 2007 Initial publication. 2 SEP 2012 5 Year Refresh. (Elastomers Global Subsystem Leadership Team) Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
