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igem news – yppc

VALVE CARE TOOLBOX

Josh Eades, Project Engineer for Pipelines Maintenance between the ball valve closures,
Centre and YPPC 2018 finalist allowing pressure-holding capability
on the ball (Cameron Valve and
THE PROBLEM OF inadequate sealing review established the context of the Measurement Group, 2009).
of buried large diameter mechanical problem statement, which was required The Cort valve has been worked on
ball valves has been identified over a to confirm the direction of the project. less for the identified problem when
number of sites throughout the UK and This was achieved by understanding, compared to the Cameron valve; this
has the potential to cause significant analysing, and gathering information could be due to the smaller number
risk to UK gas supplies. from the following information sources, of these valves within the network
This project aimed to research gathered with the assistance of the (Wilde, 2017).
a ‘toolbox’ of technologies for the National Grid Network Engineering Team: The Cameron T31 fully welded ball
wider gas transmission/distribution T/PR/MAINT/5030 Work Procedure valve, shown in Figure 2 (Cameron
industry capable of addressing a for the functional check of critical Valve and Measurement Group, 2009),
range valve maintenance issues, with valves with inlet pressures above 7 Bar operates in a similar way to the Cort
a particular focus on buried valves (Richard Waine, 2017) valve. The main difference being that
suffering from corrosion. G19/T/085 The Safe Adaption of the Cameron valve has provision for
This project was designed to identify Blind Plugs on Ball Valve Sealant Port sealant injection through side access
new ideas and then challenge their Connections and Body Vent Cavity ports, along with view ports that, if left
appropriateness using basic engineering Connections (Tim Green, 2015) open, can result in increased ingress
tools, producing a shortlist of potential T/SP/V/6 Steel Valves for use with Natural for contaminants (Cameron Valve and
solutions that can be used to overcome Gas at normal operating pressures above Measurement Group, 2009).
the identified problem statement. 7 bar (Kate Neary, 2016)
This ‘innovation hot-housing’ Kings Lynn Initial Site Assessment Operating conditions
method enables the conceptualisation (Richards, 2017) From both the Richards and DNV
and evaluation of the most promising Flooded Valve Stem Investigation (DNV GL reports, along with the technical
concepts to be carried out, in an GL, 2016) interviews, it is clear that the below
appropriate manner, without the Cort C-B5 Trunnion Mounted Manual ground valves mentioned within the
overheads of a full engineering design (Robert Cort, August 2013) report operate in similar conditions.
process. It also provides a work package Cameron Type 31 Fully Welded Body These conditions relate to the gas flow,
to carry out early-stage basic prototype Ball Valve (Cameron Valve and gas quality and operating temperatures.
testing in the field. Measurement Group, 2009) The main question arising from these
Throughout the project, over 90 Valve Investigations Questionnaire separate sources of information
separate concepts and technologies (Brown, 2017) concerns actual ground conditions
were identified as providing potential Valve Investigations Questionnaire surrounding the valve, from PH levels
specific solutions to the challenges (Wilde, 2017) to the level of the ground water table.
identified. Using a number of different A number of subsections were discussed: In reviewing the above literature,
quantitative and qualitative techniques, it became apparent that the initial
26 concepts were shortlisted. Types of valve design problem statement had been previously
These have been split into three The National Grid Gas Network identified, resulting in a general
concept groups, aiming to address the operates with two main types of ball consensus that below ground ball valves
areas of: valve. These are Cameron and Cort. “have a high risk of failing to operate on
Assessing the situation and current The valves operate in a similar manner, demand in sub-zero weather conditions
condition of the infrastructure differing mainly in their design. due to water in the valve stems that may
Cleaning the area of fouling As part of the technical interviews, free and prevent station and unit valves
Protecting the valve stem assemblies it was discovered that National Grid from operating.” (DNV GL, 2016)
for future use also operates Audco plug valves; A report from Dr Graham Richards,
The next phase of the project was a however these are not included within of OGI Ground Water Specialists, on a
feasibility assessment to identify which this project due to their above ground site prone to previous operational valve
concepts would be appropriate for application and no identified defects issues, states that “ground water was
future field trials. (Brown, 2017). seen within the bi-directional pipework
The Cort C-B5 ball valve shown in pits up to a level of approximately
Preliminary literature review Figure 1 (Robert Cort, August 2013), 300mm below the top of the concrete
The literature review focused on the uses a three-piece, bolted body design, surrounding the pits. This seemed
existing operational knowledge of manufactured from ring rolled forgings. to coincide with the level of standing
the subject in question, providing an The cast or forged ball features an water surrounding the maintenance
overview of the current findings and integral and external trunnion, which pits.” (Richards, 2017)
bringing into focus areas that have yet turns within the bearing mountings. Within the DNV GL Paper, it was
to be explored by current literature. The The bearing retainers are located reported that “Nine out of the fifteen

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