3D Modelling allows Severn Glocon to Improve Market - Castings ...

CASE STUDY No 6
www.evalve.org.uk
www.evalve.org.uk
3D Modelling allows Severn Glocon to Improve Market
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Severn Glocon have been designing and manufacturing control valves and actuators for over 40 years,
giving them extensive international experience across the whole spectrum of the process industry. Competition
with the global valve market means that the Gloucester based company has developed its own
niche in which Specials are Standard. In other words, their ability to meet their customers’ exacting and
specifi c requirements is part of everyday life at the company, and as a result valves are manufactured:
• in a wide range of alloys from carbon steel to super duplex stainless steel;
• with fi nished weights up to 9 tonnes;
• in sizes ranging from 0.5 to 36 inch with varied pressure ratings;
• with high levels of NDT to satisfy the relevant inspection authority;
• to exacting lead times.
As the company’s designs are stored in the form of drawings, there is tremendous demand on resources
in terms of storage capacity and people to maintain traceability. An additional problem experienced by
Severn Glocon is that they are often asked to refurbish or replace valves without having the original
designs. This often requires machining valve bodies from solid material. The company therefore saw
the need to investigate investment in a 3D modelling package that could be used fi rstly to store all their
existing 2D designs, and secondly to re-model third party valves effi ciently. Therefore, a partnership was
set up between Severn Glocon, Cti and UK Steel Foundries under the ICT Carrier Project.
Key project objectives
• assist Severn Glocon design engineers to select the most appropriate
3D modelling package to meet their requirements, import 2D drawings
from Bentley Microstation and design valves in 3D.
• provide the additional operator training required to model valve bodies in
3D
• demonstrate the use of 3D modelling as a means of reducing the need
to machine “special” valves from solid material by providing a rapid, cost
effective and competitive cast equivalent.
Industrial impact
• in January 2004 10 seats of the selected 3D modelling software were
purchased by the Severn Glocon design engineers
• ICT workshops provided throughout the duration of the project and the
technical support and availability of Cti’s design engineers were pivotal
in highlighting the differences between the two software packages being
investigated
• the use of the Patternless Process has been demonstrated to Severn
Glocon as a quick and cost-effective alternative to machining a valve
from wrought material
• two UK foundries participated in the exercise of exploiting 3D models for
machining moulds and cores from blocks of chemically bonded sand. In
all cases, valve bodies with cast weights ranging from 1400 to 2700kg
have been manufactured without prejudice to quality, cost or delivery.

Why was this work necessary?
Severn Glocon is an experienced manufacturer of valves
and actuators, and their customers demand a wide range
of products, to such an extent that Specials are Standard.
Valves are produced in a wide range of materials, sizes,
fi nished weights, to high levels of NDT and to exacting
lead times.
Foundry selection is largely determined by the alloys and
casting weights available, and virtually all of the valve
bodies purchased are manufactured from traditional pattern
equipment using the sand casting process. Traditional
pattern equipment is modifi ed to meet changes to
design requirements, the designs for which are based
on 2D drawings that occupy a vast fl oor area and require
several people to maintain traceability.
The refurbishment or replacement of third party valves
can also pose a problem. Severn Glocon may not have
access to the original pattern equipment or an equivalent,
which can be rapidly modifi ed to meet the engineering criteria.
The company typically machines the valve internal
shape from forged material - a costly and time consuming
process. As a result, the company has been searching
for an alternative method to eliminate the numerous manhours
spent machining the valve from solid. These two issues
of replacing 2D drawings and machining valves from
forgings formed the focus of the joint ICT Carrier Project
between Severn Glocon, Cti and UK Steel Foundries.
Key steps on the road to success
For the introduction of 3D modelling to a traditional valve
company to be successful, a number of key points need
to be recognised. These points, based upon the experiences
of Severn Glocon, include:
• a commitment to the initiative at all levels of management
and the recognition that the introduction of 3D
modelling will take both time and money to appreciate
its full potential
• the individuals within the company selected to implement
or evaluate this new concept of working need to
be adequately skilled, ‘open-minded’ and receptive to
change
• a realisation that the introduction of the technology will
‘add value’ to the business by improving total cost reduction,
effi ciency and productivity
• knowledge that the benefi ts of the technology can be
measured, accepted and understood by the manufacturing
management
• the selection of the software package is based upon
real experiences rather than ‘perception’
• a requirement to obtain impartial technical support
from a bona-fi de third party rather than the sole reliance
of the software vendor
• ensuring that the supply chain is capable of exploiting
3D data to its maximum potential
• patience is required.
Exploiting 3D models for rapid prototyping within
the valve and other manufacturing sectors
The significance of a rapid prototype is clearly one of defi -
nition. In this exemplar we consider a maximum fi nished
casting weight of the prototype of 1420kg. The use of
3D models opens the mind to opportunities for increasing
the prototyping envelope in terms of dimension and, as a
result, mass. The use of the Patternless Process at this
time is only restricted by the capacity of the CNC milling
machine currently available at Cti. Therefore, the upper
limit in terms of mass has yet to be determined.
A 3D model of a valve is used to create the cutter path
data for milling of sand blocks. The Patternless Process
can be applied regardless of valve size. In fact, the
larger the valve the more cost-effective the technology
becomes. Two limiting factors exist, the size of the sandmilling
machine and foundry melting capacity. This latter
constraint is overcome by transporting the moulds to the
host foundry for pouring and finishing.
The positive results from the use of this technology has
prompted industrialists within the donor sector to make
the following comments:
“The casting was delivered ahead of schedule and was
processed without problem, further confirming Severn Glocon’s
faith in the Patternless Process” – Alan Homfray,
Technical and Commercial Manager of Severn Glocon.
“It was a beautiful casting with an excellent casting surface
finish, proving that the technology works and can’t
be faulted”. – Ian Furniss, Managing Director of Furniss
& White.
“The casting surface finish and integrity was excellent
and exceeded the client’s specifi ed quality requirements”.
– Simon Alexander, Managing Director of Norton Cast
Products Ltd.
Whilst the Patternless Process has been focused upon
the Valve and Marine market sectors, it is clearly applicable
to other manufacturing sectors requiring rapid prototypes
of large mass, with exacting delivery requirements
and where quality and accuracy are critical. The use of
this UK developed technology provides both casting users
and producers with a unique chance of exploiting a market
need and thereby securing new markets opportunities.
Case Study prepared by Castings Technology International,
7 East Bank Road, Sheffield, S2 3PT, UK.
Tel +44 (0)114 272 8647 Fax +44 (0)114 273 0852
info@castingstechnology.com www.castingstechnology.com
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