• Development of a test method to measure the vent rates using standard flow metering approaches, the GL high flow sampling system or similar apparatus

• Laboratory tests on a Bristol Babcock and Becker controller with tests to establish that the manufacturers quoted release rates can be validated, the correlation between control pressure and vent rate and the validation of the off-site measurement method

• Site tests on up to ten sites covering all the controller vents at each site. This work will focus on individual controllers, investigating the impacts of actuation pressure, controller type and other installation specific parameters. The tests will typically be completed within one-days’ site visit, although retesting may be required. During these visits an assessment will be made on the practicality of vent modification for the continuous 24-hour testing described below

• Site test work at four selected sites to cover a continuous 24-hour period at three times over the year – proposed mid-summer, “shoulder” month and mid-winter, to establish the impact of flows and network demand

• Correlate the measured emission rates/controller type with data from DNCC to establish.

This one stage research project seeks to undertake a practical study to gain a better insight on the actual leakage rates from selected venting controllers.

This study will be used to inform a potential further piece of work to develop an extended modelling approach to predict the emission rates on a regional basis and to quantify the emission savings through a controller change-out. The expected benefits of this work will be reduced losses of natural gas at Above Ground Installations (AGIs) and reduced carbon footprint for AGI site operations related to valve positioners and controllers.