ABSTRACT for WGMSC Presentation
The natural gas utilities have decades of experience in delivering natural gas to various types of users. The utility accomplishes this by providing the user with a gas meter set that is assembled in the utility meter shop. The gas meter is “proven” to be accurate according to meter shop “prover” tests as specified by the Public Utility Commission. However, the pressure regulator is typically tested, in the field as part of the meter set field installation. The in-the-field tests include accurate pressure set point adjustment and confirmation of a no flow lockup condition when there is no demand for gas.
Natural gas meter “provers” have been used to verify the accuracy of gas meters since the early 1900s. Fast forward to the 21st century and particularly the last few decades. The vintage drum-based meter “provers” have been replaced with sonic nozzle technology which operates using constant volumetric airflow at the speed of sound. This is generally a fully automated system that is PC driven to operate the “prover” and integrate the data.
The meter set technology evolution also includes other ways and means for improving the safety of the gas user. For example, the gas pressure regulator employs various types of overpressure protection including internal relief, overpressure shutoff and various “monitor” configurations.
These protection features cannot be effectively tested in the field. The gas utilities are in the process of upgrading their meter shop platform to effectively provide in-testing and documentation for a wide range of regulator bodies and pressures in the utility meter shop.
This presentation shall put the meter set “proving” process into perspective. It shall include the basic principles of Quality Assurance and Quality Control and the procedures below:• The gas utility provides the manufacturer with procurement specifications that include testing criteria to assure the quality of the delivered product;• The manufacturer employs Root Cause Analysis to evaluate and assess any defect or gaps in performance and adjusts the manufactured product accordingly; and• The gas utility provides, in the meter shop, functional and performance tests to control the acceptance of the delivered product.
Peter Klock, P.E.Chief Engineer, ESC Engineering Servicespeter@escengineering.com