Purpose and Scope

This report is published as a guidance document to establish a common framework, as well as an industry-wide reference tool for natural gas quality and measurement provisions in contracts or tariffs. It provides an explanation of terminology and examples of representative measurement and gas quality clauses for natural gas flowing through the North American pipeline grid. Specific values or numbers in this report are provided as typical examples and are not intended to take precedence over existing contract or tariff values or to serve as industrywide standards. Rather, the document describes typical gas quality constituents and parameters with associated limits employed to minimize potential end-use impacts. The primary focus is to provide technical information for use in tariffs or contracts, including checklists, that promotes the safety and reliability of gas transmission and distribution infrastructure while maximizing supply opportunities and minimizing potential end-use concerns.

Furthermore, this report provides factors to consider when evaluating appropriate limits for gas quality specifications along with a discussion of available measurement technologies referenced in documents that specify custody transfer transactions.

Specifically this report includes:

•basic measurement and gas quality concepts, including how some constituents or parameters may impact pipeline systems and end users;

•typical ranges of constituent and parameter values found in tariffs and contracts;

•definitions for most of the terms commonly found in tariff and contract measurement and gas quality clauses; and

•appendices containing general purpose checklists and sample language for tariff and contract measurement and gas quality clauses, pipeline tariff survey data and appropriate references.