Block Valves Civils Upgrades

Toftshaw Lane, Macrae Road, St Bees & Fitz Park


Northern Gas Networks



Project Overview

Northern Gas Networks own and maintain a large number of block valves on Local Transmission Systems (LTS), which are used for isolating sections of high pressure (HP) gas pipelines.


The Challenge

The block valves are contained within below ground chambers, constructed from either concrete or masonry, with access via removable, heavy duty, steel covers.


The Solution

The design scope required coordination with a confined spaces team to provide access to the chambers for sludge clearing and asbestos surveys, prior to visual structural inspections to determine the condition of the below ground chambers, access covers and steelwork support frames and mechanical surveys of the block valves, connected pipework and fittings.


The Result

Where necessary recommendations were made for improvements and refurbishment or replacement of various items including valve fittings, pit cover support frames, pit walls and concrete slabs.

The access chamber covers were recommended to be replaced with lighter weight GRP and were specified to be lockable.

Additional works included site signage, marker posts, fencing and grit blasting and re-painting of valves and associated pipework.