Page 22 - Gi flipbook - October 2018

Renovation, renovation, renovation

equipment, which was brought above
ground for easy access. The best FIGURE 9 Design image of planned FIGURE 10 One of six block valve
available techniques for assessment completed block valve site installations completed by NARC
were undertaken at the Cambridge
tee, leading to the installation of
three electro-hydraulic actuators,
improving our environmental
footprint as well as meeting safety
and operational requirements.
Part of NARC’s innovation remit was
to assess the condition of Feeder 3
valves removed from the ground as
part of the replacement block valve
works, having provided over 45 years
of service. Two contractors were
commissioned with random samples FIGURE 11 Top previous Cambridge tee pit, FIGURE 12 Guestwick AGI, during a 24 hour
taken to conduct material analysis bottom, New Cambridge tee continuous working period in order to
that has been fed back into our needs secure UK gas supplies
case and justification models.
The innovation project for
glassfiber reinforced plastic (GRP)
pipe supports has been successfully
progressed for use in 2018. A
prototype was manufactured, crush
testing has confirmed its vertical load
capability and a design specification
has been produced. Installation is
scheduled for later this year.
During summer 2017, surveys and
conceptual design reports were
completed for five feeder sections
and five compressor stations/large
AGIs to inform the work scope of our FIGURE 13 Design image, utilising BIM, of
second year of delivery (NARC 2). Brisley site works delivered for NARC 2 in
Three CDP meetings over one month 2018
successfully agreed the NARC 2
scope. NARC 2’s site construction is
nearing completion, with four new
installation rebuilds, five separate
national feeder pipe-throughs and
over 10 installations revalidated
through P/11 inspections.
Current declared efficiencies for
NARC this annum are £9 million, of
which £4 million came from utilising The following innovations are
pipe-through solutions instead of planned for incorporation into NARC
full site replacements and 2 during 2018: ■ NARC is currently reviewing shallow
coordinating multiple works under ■ Continuing the strategy of using high dig techniques for vent and sealant
single pipeline shutdowns. The rest performance gearboxes on locally- line replacement on block valves for
was due to competitive tender, operated valves, but further utilisation suitable for the campaign.
contractor efficiencies, and developing the use of these ■ Following learnings from corrosion
recompression efficiencies. gearboxes to replace remote valve of the V/6 specified welded vent
Business information modelling actuation. and sealant line supports, NARC
(BIM) utilisation has continued with ■ Planning the first ever site has implemented a design change
great success for NARC 2 construction installation of GRP supports which, with our 2018 long lead valve
works, not just with the creation of due to our smart split body design, supplier to ensure ball valves are
modular designs, but especially in the enables the support to be supplied with plastic anti-corrosion
negotiation and agreement to date of withdrawn from the pipeline and clips. These are currently being
several difficult outage works with re-used, it allows easier and cheaper manufactured in Germany. ■
third parties. It embeds the temporary withdrawal for pipeline inspection,
works design with the permanent it’s lightweight and will not corrode, ■ For more information, contact
works, increasing installation efficiency has a design life of 40 years and is author Chris Bates via email at
and safety, reducing risk and cost. cheaper to purchase. christopher.j.bates@nationalgrid.com

22

AGIRenovation.indd 3 20/09/2018 14:00