1、American Petroleum Ins ti tut e RESULTS OF RANGE-FINDING TESTING OF LEAK DETECTION AND LEAK LOCATION TECHNOLOGIES FOR UNDERGROUND PIPELINES HEALTH AND ENVIRONMENTAL AFFAIRS DEPARTMENT PUBLICATION NUMBER 346 NOVEMBER 1998 Am erica n Petroleum Institute American Petroleum Institute Environmental, Heal
2、th, and Safety Mission and Guiding Principles MISSION The nienibers of the American Petroleum Institute are dedicated to continuous eflorts to iniprove the cornpatibiliq of our operations with the environment while economically deileloping energy resources and supplying high quality products and sen
3、ices to consumers. We recognize our responsibilifv to work with the public, the government, and others to develop and to use natural resources in an environmentally sound manner while protecting the health and safety of our employees and the public. To meet these responsibilities, API members pledge
4、 to manage our businesses according to the following principles using sound science to prioritize risks arid to implement cost-effective management practices: 0 To recognize and to respond to community concerns about our raw materials, products and operations. PRINCIPLES 0 To operate our plants and
5、facilities, and to handle our raw materials and products in a manner that protects the environment, and the safety and health of our employees and the public. 0 To make safety, health and environmental considerations a priority in our planning, and our development of new products and processes. 0 To
6、 advise promptly, appropriate officials, employees, customers and the public of information on significant industry-related safety, health and environmental hazards, and to recommend protective measures. 0 To counsel customers, transporters and others in the safe use, transportation and disposal of
7、our raw materials, products and waste materials. 0 To economically develop and produce natural resources and to conserve those resources by using energy efficiently. 0 To extend knowledge by conducting or supporting research on the safety, health and environmental effects of our raw materials, produ
8、cts, processes and waste materials. 0 To commit to reduce overall emission and waste generation. 0 To work with others to resolve problems created by handling and disposal of hazardous substances from our operations. 0 To participate with government and others in creating responsible laws, regulatio
9、ns and standards to safeguard the community, workplace and environment. 0 To promote these principles and practices by sharing experiences and offering assistance to others who produce, handle, use, transport or dispose of similar raw materials, petroleum products and wastes. Results of Range-Findin
10、g Testing of Leak Detection and Leak Location Technologies for Underground Pipelines Health and Environmental Affairs Department API PUBLICATION NUMBER 346 PREPARED UNDER CONTRACT BY: JAWS D. FLORA, JR., PH.D. WILLIAM D. GLAUZ, PH.D. JOE HENNON MIDWEST RESEARCH INSTITUTE 425 VOLKER BOULEVARD KANSAS
11、CITY, MO 641 10-2299 NOVEMBER 1998 American Petroleum Institute - STD-APIiPETRO PUBL 3Llb-ENGL 1778 IO732290 ObL3b35 BT7 FOREWORD API PUBLICATIONS NECESSARILY ADDRESS PROBLEMS OF A GENERAL NATURE. WITH RESPECT TO PARTICULAR CIRCUMSTANCES, LOCAL, STATE, AND FEDERAL LAWS AND REGULATIONS SHOULD BE REVI
12、EWED. MI IS NOT UNDERTAKING TO MEET THE DUTlES OF EMPLOYERS, MANUFAC- TURERS, OR SUPPLIERS TO WARN AND PROPERLY TRAIN AND EQUIP THEIR EMPLOYEES, AND OTHERS EXPOSED, CONCERNING HEALTH AND SAFETY RISKS AND PRECAUTIONS, NOR UNDERTAKING THEIR OBLIGATIONS UNDER LOCAL, STATE, OR FEDERAL LAWS. NOTHING CONT
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14、NSTRUED AS INSURING ANYONE AGAINST LIABIL- All rights reserved. No part of this work may be reproduced, storzd in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise, without prwr written permission from the publishex Contact the publisher,
15、API Publishing Services, 1220 L Street, N.W, Washington, D.C. 20005. Copyright 0 1998 American Petroleum Institute iii Previous page is blank STD-APIIPETRO PUBL 3Yb-ENGL L97a 6 0732290 Ob13b3b 733 W ACKNOWLEDGMENTS THE FOLLOWING PEOPLE ARE RECOGNIZED FOR THEIR CONTRIBUTIONS OF TIME AND EXPERTISE DUR
16、ING THIS STUDY AND IN THE PREPARATION OF THIS REPORT API STAFF CONTACTS Dee Gavora, Health and Environmental Affairs Department Andrew Jaques, Health and Environmental Affairs Department MEMBERS OF THE LEAK DETEC TION WORKGROUP Aiian Wolf, Chairperson, Exxon Ronald M. Bass, Sheii Development Company
17、 Nimish Dhuldhoya, Texaco Frank Funllo, Mobil Technology Corporation Jerry Horak, Exxon Laurence Hudson, Texaco Eugene P. Milunec, Mobil Philip E. Myers, Chevron Products Company Anh N. Nguyen, Colonial Pipeline Company iv - STD.API/PETRO PUBC 3Yb-ENGh 199B m 0732290 Ob13b37 b7T D ABSTRACT This stud
18、y reviewed the leak detection and leak location methods for pressurized underground piping. The review selected candidate methods for testing underground piping of diameters of 6 to 18 inches and lengths of 250 feet to about 2 miles. Such underground piping is commonly found at airports, refineries,
19、 and fuel terminals. Methods that appeared promising were further reviewed, and four technologies were selected for field demonstration in range-finding tests. The four technologies were constant-pressure volumetric testing, pressure-decay testing, chemical tracer testing, and acoustic emission test
20、ing. Range- finding tests were conducted at an operating facility, using pipeline sections of different volumes. The methods were tested on tight lines, lines with induced leaks, and one line with an operational leak. The approximate size of a leak that each method could detect was estimated. Method
21、s that could locate leaks were used to identi the operational leak, which was confirmed by excavation and repair. STD.API/PETRO PUBL 3Yb-ENGL 1798 R 3732290 ObL3b38 50b = TABLE OF CONTENTS Section Page EXECUTIVE SUMMARY . ES- 1 1 . NTRODUCTION 1 . 1 HISTORY 1-2 PROJECT BACKGROUND . 1-2 TECHNOLOGIES
22、THAT WERE REPRESENTED IN THE PROJECT 1-3 2 . SCOPE AND OBJECTIVES 2-1 GENERAL PROJECT OBJECTIVES 2-1 SCOPE OF THE TESTING 2-1 TECHNOLOGY-SPECIFIC OBJECTIVES . 2-3 3 . PROTOCOLS AND TEST METHODS . 3-1 TEST SITE 3-1 GENERAL PROJECT PROTOCOLS 3-4 TECHNOLOGY-SPECIFIC PROTOCOLS . 3-5 TEST METHODS . 3-26
23、TESTING LIMITATIONS 3-32 4 . OBSERVATIONS AND RESULTS 4-1 VOLUMETRIC . 4-1 TRACER . 4-12 PRESSURE DECAY METHOD 4-22 ACOUSTIC EMISSIONS METHOD . 4-31 5 . FIELD INSPECTION RESULTS . 5-1 FIELD INSPECTION . 5-1 COMPARISON TO LEAK LOCATION ESTIMATES BY VENDORS 5-5 6 . RESULTS/FINDINGS . 6-1 REFERENCE LIS
24、T . R-1 Appendix A DATA REPORT FROM VISTA RESEARCH A-1 Appendix B REPORT FROM TRACER RESEARCH . B- 1 Appendix C REPORT FROM HANSA CONSULT TCS . C-1 Appendix D REPORT FROM PHYSICAL ACOUSTICS CORPORATION D-1 STDmAPI/PETRG PUBL 34b-ENGL 1778 3732290 ObL3b40 Lbq LIST OF FIGURES Figure Page 1 . 2 . Test
25、Facility 3-2 Pumps and Location of the End of Line 1 . 3-3 3 . 4 . 5 . 6 . 7 . 8 . 9 . 10 . 11 . 12 . 13 . 14 . 15 . 16 . 17 . 18 . 19 . 20 . 21 . 22 . 23 . 24 . 25 . 26 . 27 . The Large Volumetric System 3-6 The Smailer Volumetric Unit Conducting a Test . 3-8 MRI Conducting a Leak Simulation 3-9 Co
26、nnections of the Larger and Smaller Volumetric System at High Point 4 . 3-10 Leak Simulators at High Point 3 . 3-10 Drilling to Install Tracer Ports 3-15 Injecting Tracer in Product as the Line is Filled . 3-16 Installing Sampling Ports for Tracer 3-17 Sampling Soil Gas for Tracer 3-18 Injecting Tra
27、cer with Compressor Air in Line 4 . 3-19 The Gas Chromatograph Used to Analyze Soil Gas Samples for Tracer 3-19 Procedure of a Pressure Decay Test with Its Three Test Cycles (test pressure high-low-high) . 3-21 Installing the Pressure Sensor for the Pressure Decay Method 3-23 The Power Supply, Compu
28、ter, and Printer Connected to the Pressure Decay System . 3-23 The Pressure Decay System Installed 3-24 Computer Used for Collecting and Analyzing Data for Pressure Decay System . 3-24 Drilling to Get Access to Pipe for Acoustic Emissions System 3-27 Equipment Unit for the Acoustic Emissions System
29、3-28 Location of Sampling Probe for Tracer . 4-14 Location of Excavations . 5-2 Fill Material in Bell Hole 1 5-3 Location of Pits 5-6 Perforation of Pipe . 5-7 Link Seal after Removal 5-8 Detail of Pipe and Sleeve 5-9 LIST OF TABLES Table ES.l . Comparison of Technologies e5-4 1 . 2 . 3 . 4 . 5 . 6
30、. 7 . 8 . 9 . 10 . 11 . 12 . 13 . 14 . 15 . 16 . 17 . 18 . 19 . Volumetric Test Results on Line 1 4-4 Volumetric Test Results on Line 2 4-6 Volumetric Test Results on Line 3 4-7 Volumetric Test Results on Line 4 4-8 Verbally Reported Leak Rates for Line 1 4-10 Statistical Results for Volumetric Test
31、s . 4-11 48-Hour Test with Tracer 1 on Line 3 (pg/l) (December 6, 1996) . 4-18 48-Hour Test with Tracer 3 on Line 3 (pg/l) (December 12, 1996) . 4-19 48-Hour Test with Tracer 1 on Line 4 (pg/l) (December 4, 1996) . 4-19 72-Hour Test with Tracer 1 on Line 4 (pgA) (December 6, 1996) . 4-20 2-Hour Test
32、 with Tracer 3 on Line 4 (pg) (December 12, 1996) . 4-21 Results from Pressure Decay Method on Line 1 4-25 Results from Pressure Decay Method on Line 2 4-27 Results from Pressure Decay Method on Line 3 4-28 Statistical Results for Pressure Decay Data . 4-30 Results from Acoustic Emissions Method on
33、Line 2 4-34 Results from Acoustic Emissions Method on Line 3 4-35 Results from Acoustic Emissions Method on Line 4 4-36 Results from Acoustic Emissions Method on Line 5 4-38 STD-APIIPETRO PUBL 34b-ENGL 1978 lss 3732290 Ob13b42 “37 M EXECUTIVE SUMMARY This study reviewed the available literature and
34、other sources to identi6 methods of leak detection and leak location for pressurized underground piping. The size of the piping that was the subject of this research was larger than that found in retail fueling applications but smaller than cross-country transmission pipelines. The population of pip
35、elines targeted ranged from about 6 to 18 inches in diameter and from about 250 feet to 2 miles long. Such piping is commonly found at airports, refineries, bulk plants, and fuel terminals. The technologies that were identified were constant-pressure volumetric testing, pressure-decay tests, chemica
36、l tracer tests, acoustic emission tests, radioactive tracer tests, product inventory reconciliation analysis, and computerized pressure-flow analysis. Vendors of four different technologies (constant-pressure volumetric tests, pressure-decay testing, chemical tracer testing, and acoustical emission
37、tests) were identified and invited to participate in the research study. The first two technologies purport to detect a leak and measure its size, while the latter two methods purport to detect leaks and identifj their location. The four methods were subjected to range-finding tests at an operating
38、facility. Up to four different line sections of different volumes ranging from 1,600 gallons to 9,700 gallons were used in the testing. Tests were done on tight lines, on lines with simulated leaks, and on one line with a large operational leak. The volumetric test method demonstrated the capacity t
39、o detect and measure leaks ranging from about 0.2 gallon per hour (gph) to 0.6 gph. The size of the leak that it can detect is a function of the volume of the line tested, in a fixed duration test. The system is designed for rapid mobilization to a test site and use as a point-in-time test. It has t
40、he potential to be permanently installed at a site and used for periodic testing. It requires that the sections of line to be tested be isolated with tight valves or blind flanges and tested in a static condition. The system checks the bulk modulus of the line. In the tests observed, the operators r
41、equired that the line be nearly air- free. Once set up, a test requires about 2 hours. There are two differently sized systems designed ES- 1 STD.API/PETRO PUBL 3gb-ENGL 5798 = 0732290 ObL3b43 973 for differently sized lines. This method identified the large operational leak and gave an approximate
42、leak rate-the actual leak was too large for the system to measure without an additional source of fuel to keep the line under constant pressure. It tested a line with an unknown leak of about 0.2 gph, identified that the line was leaking, and estimated the leak rate as about 0.2 gph. The chemical tr
43、acer method demonstrated the ability to detect a leak of 0.05 gph that persisted for at least 36 hours with tracer-labeled material. The tracer method can be used in a variety of different operating conditions: tracer inoculated product can be placed in the line under pressure in a static condition,
44、 the product can be inoculated with tracer and circulated through the line, or the line can be emptied and pressurized with tracer-labeled air. The choice depends on the operating conditions at a site. The tracer method was tested with liquid product in a static condition, and with tracer in air in
45、a static test. The tracer method gave no false alarms on a tight line. It identified the operational leak and identified three suspect areas, one of which was confirmed by excavation and repair. The tracer method requires inoculation with tracer, installation of sampling probes, then sampling and an
46、alysis several days after inoculation, depending on site conditions. Special procedures were used for these tests since introduction of the tracer material in fuel is not yet approved by the FAA for commercial aircraft. The pressure-decay method was found to be designed for permanent installation. A
47、s such, it requires calibration to each section of pipe to be tested-performing a number of calibration tests with the line tight and with known simulated leak rates. It is not intended for use as a one-time test method. Once calibrated, it detected simulated leaks and measured them. It uses a thres
48、hold for leak detection that is proportional to the volume of the pipeline, equivalent to 0.004% of the volume of the line per hour. When tested on a line with a large Operational leak, it identified the leak quickly through the lines failure to hold pressure. When tested on a line with an unknown l
49、eak of about 0.2 gph, the operators were unable to calibrate the system. After about a day and a half of testing, they concluded that the line must have a leak, which was then confirmed as leaking past a blind flange. The method requires absolutely tight valves to isolate line sections L,- ES-2 for testing. It also requires the lines to be essentially air-free. In permanent installation, it requires remotely operated double-block-and-bleed valves. A pipe section can be tested in about 45 minutes, once the system is calibrated. The acoustic emission test requires physical access
