Design and Placement of Compact Service Regulators

Overview

Main Objective

Through reviewing existing practices and comparative testing, this project will provide recommendations and guidance to the natural gas industry on "vent-limiting" service regulators and will improve a gas utility's ability to install or move the service regulator to the outside of the structure. The project will measure the exact level of natural gas produced from "vent-limiting" service regulators as compared to traditional IVR service regulators to determine safe clearance distance requirements. This project will determine whether "vent-limiting" service regulators offer more options for outside installation by having a smaller footprint that includes the ability to install at reduced clearances as compared to traditional IVR service regulators.

Public Abstract

The objective of this project is to provide natural gas utilities with additional options for the safe, outside installation of service regulators and meter sets. Current federal and local codes, industry standards, and utility procedures require a minimum clearance distance from the service regulator vent to building openings (doors and windows), vents, and possible ignition sources. These safety requirements limit the ability for utilities to install new or relocate existing indoor meters and service regulators on the outside of buildings. However, new vent limiting service regulators are now available on the market with an overall smaller footprint with less or no clearance requirements. This project aims to evaluate these new vent limiting regulators and to create guidelines and recommendations for the safe reduction of the minimum clearance distances, therefore, improving the ability of the service regulator to be installed outside.

Methodology: Work with natural gas utilities, Technical Advisory Panel (TAP) members, regulator manufacturers, and industry subject-matter experts to: a) evaluate existing industry code requirements, standards, and utility procedures for the installation and minimum clearance requirements of service regulators, b) comparative testing of both traditional Internal Relief Valve and newer vent limiting service regulators, and c) develop new guidelines and recommendations, based on the testing, for a reduction of the minimum clearance distances for vent limiting service regulators, therefore, improving the ability of the regulator to be installed outside.

Potential Impact on Safety: Gas leaks inside buildings can lead to explosions or carbon monoxide poisoning; moving regulators outdoors minimizes this risk. Additionally, regulators located outdoors might be easier to access for maintenance and inspection, potentially leading to earlier detection and repair of potential issues. Establishing clear guidelines for vent-limiting regulators can also promote consistent safety practices across the natural gas industry.

Summary and Conclusions

This project is co-funded by DOT PHMSA with an objective to provide natural gas utilities with data for additional options for the safe, outside installation of service regulators and meter sets. The objective of the project is to perform research on newer "vent limiting" gas service regulators to determine safe clearance allowances and installation practices that will provide a gas utility with more options for outside installation. The objectives of the project included:

• Review the existing industry practices for "vent limiting" service regulators, including those in other countries.
• Perform comparative emissions testing for "vent limiting" gas service regulators.
• Provide installation recommendations on safe distance allowances to the industry. Some local codes, industry standards, and utility procedures require a minimum clearance distance from the service regulator vent to building openings (doors and windows), vents, and possible ignition sources. In certain scenarios, there is difficulty to find safe clearance distances and therefore making it less desirable to install new or relocate existing indoor meters and regulators on the outside of the building. However, new vent limiting service regulators are now available on the market with an overall smaller footprint with less or no clearance requirements. This project evaluated these new vent limiting regulators and worked to create data that can be used in guidelines and recommendations for the safe reduction of the minimum clearance distances, therefore, improving the ability of the service regulator to be installed outside.

This project reviewed existing practices and performed comparative service regulator testing that resulted in data that can be used for guidance to the natural gas industry on "vent-limiting" service regulators. The data results may provide more options for a gas utility to install or move the service regulator and/or meter set to the outside of the structure. The project measured the level of natural gas produced from "vent-limiting" service regulators as compared to traditional IRV service regulators to determine safe clearance distance requirements. Experimental testing has determined that "vent-limiting" service regulators offer more options for outside installation by having a smaller footprint that includes the ability to install at reduced clearance distances as compared to traditional internal relief valve (IRV) service regulators. The safe distance allowances can be determined through the testing data results for the amount of gas vented during various regulator operating flow conditions (normal and abnormal) and failure modes, including diaphragm ruptures.

The project provided scientific data demonstrating that newer vent limiting gas service regulators with an over pressure shut off (OPSO) vent less gas emissions as compared to traditional IRV during abnormal conditions. The test plan provides a list of gas service regulators that were tested as part of this project, however the manufacturer and model for each of the regulators is not listed in the results section of the public report.

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