A Full Scale Experimental Study of Fires Following the Rupture of Natural Gas Transmission Pipelines

Abstract

The gas industry has an excellent safety record in operating high pressure transmission pipelines. Nevertheless, it is important that pipeline operators have an understanding of the possible consequences of an accidental gas release, which may ignite, in order to help manage the risks involved. This paper describes two full scale experiments, conducted as part of a research programme into the consequences of pipeline failures, undertaken by an international collaboration of gas companies. The experiments involved the deliberate rupture of a 76km length of 914mm diameter natural gas pipeline operating at a pressure of 60 bar, with the released gas ignited immediately following the failure. Instrumentation was deployed to take detailed measurements, which included the weather conditions, the gas outflow, the size and shape of the resulting fire, and the thermal radiation levels. The results provide important data for the validation of mathematical models, used in developing risk assessment methodologies, and in establishing those standards and design codes for gas pipelines that are risk based.

A model for the initial stages following the rupture of a natural gas transmission pipeline

“…Figure 4 shows a comparison with data obtained during the second Canadian full-scale experiment, Acton et al (2000), 32 seconds after the start of the release. This provides some evidence for the performance of the correlations in the stalk model deduced from the predictions of the integral fire model that would normally be used for this purpose.…”

“…A number of predictive models have been developed for the wave speed associated with different initial conditions in the pipe (see Groves et al, 1978 The model has been compared with experimental data (see 0Acton et al, 1998and Cleaver et al, 2001 for further details of the experiments). This covers experiments carried out over the full range of scales from those carried out in Canada, see Acton et al (2000), on a natural gas transmission pipeline to the reduced scaled experiments, see Norris (1994). An example of the comparison of the model with data obtained during the full-scale experiment is shown in Figure 1 below.…”

Comparative Study on Blast Wave Propagation of Natural Gas Vapor Cloud Explosions in Open Space Based on a Full-Scale Experiment and PHAST

“…As concern has increased about the possible consequences of a natural gas explosion in industrial plants, accurate predictions of such explosions are needed. Several large-scale experimental studies for high-pressure natural gas pipelines have been conducted in support of the development of the internationally used pipeline risk assessment for natural gas pipelines, and two pipeline rupture experiments were performed at full scale . More recently, two pipeline rupture experiments were performed using a similar test rig with a 150 mm diameter pipeline pressurized with natural gas .…”

Experimental Studies of Releases of High Pressure Natural Gas From Punctures and Rips in Above-Ground Pipework

“…Nevertheless, it is important that pipeline operators have an understanding of the consequences of possible accidental gas releases, in order to help manage the risks involved. To obtain such information, an international group of gas companies has collaborated to undertake a research programme, involving mathematical modeling [1] and both small and large scale experiments, including two full scale experiments to study the potential consequences of a rupture of an underground gas transmission pipeline [2].…”