0

Full Content is available to subscribers

Subscribe/Learn More  >

How Dry Is Dry?

[+] Author Affiliations
C. Hartloper, K. K. Botros

NOVA Chemicals Centre for Applied Research, Calgary, AB, Canada

V. Liu, G. Lalonde, J. Lu, Y. Saud de Puche

TransCanada Pipelines Limited, Calgary, AB, Canada

Paper No. IPC2018-78580, pp. V002T02A007; 8 pages
doi:10.1115/IPC2018-78580
From:
  • 2018 12th International Pipeline Conference
  • Volume 2: Pipeline Safety Management Systems; Project Management, Design, Construction, and Environmental Issues; Strain Based Design; Risk and Reliability; Northern Offshore and Production Pipelines
  • Calgary, Alberta, Canada, September 24–28, 2018
  • Conference Sponsors: Pipeline Division
  • ISBN: 978-0-7918-5187-6
  • Copyright © 2018 by ASME

abstract

Air drying is used after dewatering to dry a pipeline or piping facility before commissioning it with natural gas. This process typically involves blowing dehydrated air through the pipe sections until they are determined to be suitably dry. The question addressed in this paper is: how dry is dry? A common metric used to judge the pipe section’s dryness is the drying air’s outlet water dew point. Typically, air drying continues until a suitably dry low water dew point, such as −40°C, is measured at the outlet of the pipeline or facility. However, there is currently a lack of understanding of how this final outlet water dew point relates to the remaining water and thus the subsequent start up of the pipeline or facility. If the outlet water dew point is higher than required, issues may arise upon start up; e.g., hydrates could form along the pipeline or at downstream facilities. Conversely, if the outlet water dew point is lower than required, unnecessary time would have been spent in drying, and hence higher cost.

This paper advocates an approach to determine when air drying is complete that considers the start-up phase. The approach consists of two parts. In the first part, the air drying parameters (drying air flow rate, inlet water dew point, etc.) and the final outlet water dew point are used to quantify the volume and surface area of water remaining after the drying process is completed. In the second part, the evaporation of this water into the gas flowing through the pipeline/facility after commissioning and start up is modeled as a function of the gas flow rate, temperature, pressure and inlet water content. Then, the water content of the gas at the delivery points is calculated. This increase can then be evaluated in reference to the water content specifications at the delivery points. The approach is exemplified by a 31 km NPS 48 pipeline over a mountainous terrain.

Copyright © 2018 by ASME

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In