GPA STD 2198-2003 Selection Preparation Validation Care and Storage of Natural Gas and Natural Gas Liquids Reference Standard Blends《天然气和天然气液体参考标准混合物的选择 制备 验证 照管和保存》.pdf
《GPA STD 2198-2003 Selection Preparation Validation Care and Storage of Natural Gas and Natural Gas Liquids Reference Standard Blends《天然气和天然气液体参考标准混合物的选择 制备 验证 照管和保存》.pdf》由会员分享,可在线阅读,更多相关《GPA STD 2198-2003 Selection Preparation Validation Care and Storage of Natural Gas and Natural Gas Liquids Reference Standard Blends《天然气和天然气液体参考标准混合物的选择 制备 验证 照管和保存》.pdf(11页珍藏版)》请在麦多课文档分享上搜索。
1、GPA Standard 2198-03Adopted 1998Revised 2003Gas Processors Association6526 East 60th StreetTulsa, Oklahoma 74145Selection, Preparation, Validation, Care and Storage of Natural Gas and Natural Gas Liquids Reference Standard Blends1GPA Disclaimer GPA publications necessarily address problems of a gene
2、ral nature and may be used by anyone desiring to do so. Every effort has been made by GPA to assure accuracy and reliability of the information contained in its publications. With respect to particular circumstances, local, state, and federal laws and regulations should be reviewed. It is not the in
3、tent of GPA to assume the duties of employers, manufacturers, or suppliers to warn and properly train employees, or others exposed, concerning health and safety risks or precautions. GPA makes no representation, warranty, or guarantee in connection with this publication and hereby expressly disclaim
4、s any liability or responsibility for loss or damage resulting from its use or for the violation of any federal, state, or municipal regulation with which this publication may conflict, or any infringement of letters of patent regarding apparatus, equipment, or method so covered. “Copyrignt 2003 by
5、Gas Processors Association. All rights reserved. No part of this Report may be reproduced without written consent of the Gas Processors Association.” 2GPA Standard 2198-03 for Selection, Preparation, Validation, Care and Storage of Natural Gas and Natural Gas Liquids Reference Standard Blends 1. SCO
6、PE 1.1 This method covers the recommended procedures for selecting the proper Natural Gas and Natural Gas Liquids Reference Standards, preparing the standards for use, verifying the accuracy of composition as reported by the manufacturer, and the proper care and storage of those standards to insure
7、their integrity as long as they are in use. 2. SUMMARY OF METHOD 2.1 It is highly recommended that the proper reference blend be obtained for a particular application. The accuracy of its reported composition must be authenticated when received and periodically during its use. 2.2 Special care needs
8、 to be taken to ensure the integrity of any reference standard from the time it is received until it is taken out of service. 2.2.1 It is a good Laboratory practice to order a replace-ment standard and confirm its validity well in advance of the depletion or deterioration of the reference standard b
9、lend that is presently in service. 2.3 A constant pressure cylinder used to obtain a Natural Gas Liquids Reference Standard must be properly prepared to avoid contaminating, changing or losing its contents. 2.4 All necessary Department of Transportation (DOT) requirements must be followed when trans
10、porting a Natural Gas or Natural Gas Liquids Reference Standard blend. 3. SELECTION OF A PROPER REFERENCE STANDARD BLEND 3.1 The selection of a proper reference standard blend depends upon the composition of the samples that are to be analyzed. A reference standard composition should resemble the sa
11、mples that are to be analyzed. 3.1.1 A known blend prepared by weights of high purity components (99+ per cent with known impurities) to an accuracy, as shown in Table 1, for each component is required for calibration runs. The concentration of a component in the calibration blend should be not less
12、 than one-half of the concentration of the corresponding component in the un-known. Corresponding components in the calibration blend and in the unknown should not differ by more than twenty (20) mol percent (of the total mixture) when the peak area calculation method is used. In applying these rule
13、s the values for the hexanes and heavier components may be totaled and considered as a single component. 3.1.2 In a Natural Gas Reference Standard blend containing hexane-plus components, a full spectrum of the heavies should be used when blending the reference standard. 3.1.3 A properly blended Ref
14、erence Standard should be prepared gravimetrically by the manufacturer and its composition verified by chromatographic analysis before shipment to the user. 3.2 It may be necessary for the blend user to check the linearity of an instrument before a range of instrument accuracy can be determined. (Re
15、fer to Appendix A of this standard.) 3.2.1 The linearity of the instrument will determine the range of samples that can be analyzed with a single reference standard. It may be necessary to obtain more than one reference standard blend. Table 1 Required Blending Accuracy % of Concentration % of Accur
16、acy 0.00 - 0.099% 5% Relative 0.10 - 9.999% 2% Relative 10.0 - 100% 1% Relative NOTE - Hydrogen and/or Helium are more difficult to blend. Contact the blend manufacturer for the accuracy determination of these components. 34. PREPARATION FOR ANALYZING REFERENCE STANDARDS 4.1 Before a reference stand
17、ard can be used for calibrating instruments, it needs to be properly prepared and the contents must be verified. Improper preparation can lead to inaccurate calibrations and verifications. 4.2 A Natural Gas Reference Standard must be heated to a minimum of 20F (11C) above its hydrocarbon dew point f
18、or at least 12 hours before attempting to analyze it. 4.3 The pre-charge end of a Natural Gas Liquids (NGL) Reference Standard cylinder should be pressured to not less than 200 psi (1379 kPa) above the vapor pressure of the sample at the temperature of the chromatograph injection valve (A pressure o
19、f 1000-1200 psig should be sufficient for most liquid blends). 4.3.1 The contents of a Natural Gas Liquids Reference Standard blend should be thoroughly mixed immediately before attempting to analyze it. (Refer to manufacturers information for mixer type and proper mixing instructions.) 5. NATURAL G
20、AS REFERENCE STANDARD ACCURACY DETERMINATION 5.1 Before a new reference standard blend can be used for calibrating instruments, it is highly recommended that the composition be authenticated. If the composition of the new blend does not match the gravimetric composition provided by the vendor, it sh
21、ould not be used for calibration purposes. To determine the accuracy of a new reference standard blend, these steps should be followed. 5.1.1 All regulators, gauges, and fittings that are attached to the blend cylinder should be tight and leak tested. The sample line between the blend cylinder and t
22、he gas sample valve should be as short as practical and constructed of one size tubing only (no larger than 1/8“ O.D.). CAUTION: It may be necessary to heat the sample line from the cylinder to the sample valve to prevent the loss of heavy ends. 5.1.2 Analyze the composition of the blend cylinder at
23、 least two (2) times, as an unknown, to determine the repeatability of the chromatograph. Repeatability can be confirmed by comparing the component mol percents of the analyses. Component mol percents should agree within the repeatability requirements as stated in section 8 of GPA Standard 2261-95.
24、5.1.3 Once the repeatability of the instrument has been confirmed, compare the composition of the latest analysis with the gravimetric composition supplied by the blend manufacturer. The two compositions should agree within the reproducibility values as stated in GPA 2261-95. If the two compositions
- 1.请仔细阅读文档,确保文档完整性,对于不预览、不比对内容而直接下载带来的问题本站不予受理。
- 2.下载的文档,不会出现我们的网址水印。
- 3、该文档所得收入(下载+内容+预览)归上传者、原创作者;如果您是本文档原作者,请点此认领!既往收益都归您。
下载文档到电脑,查找使用更方便
10000 积分 0人已下载
下载 | 加入VIP,交流精品资源 |
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- GPASTD21982003SELECTIONPREPARATIONVALIDATIONCAREANDSTORAGEOFNATURALGASANDNATURALGASLIQUIDSREFERENCESTANDARDBLENDS

链接地址:http://www.mydoc123.com/p-782336.html