TPT March 2007

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43 March/April 2007
Technology Update
Custom valve manufacturer Definox has
been using orbital welding for 15 years
and bought its first system from Polysoude,
France, in 1993. The company currently
operates five orbital welding power supplies
and several weld heads, including a
Polysoude PC 300 TR, which is used for
welding large, manifold parts.
The Definox product range, produced
only from 316L stainless steel tube or bar,
is used in the manufacture of food and
dairy products, wine making/brewing, and
products for chemicals and cosmetics. The
company has an extensive line of valves
including ball, butterfly, vacuum pressure
release, mix proof, changeover, non-return,
compression, double block, bleed, and
diaphragm.
In the early 1990s the company began
designing a special ‘push through’ pigging
system, to be used to empty the remaining
product from the pipe into the filling
machine. This procedure involves the
forcing of the product out of the pipeline
using air or water.
At this time, Definox was already producing
valves for the pharmaceutical industry, and
its welders were adept at producing welds
with smooth interior surfaces. This aspect of
welding is essential in avoiding the build-up
of contamination in products or to eliminate
the possibility of weld joint corrosion. The
repeatability, accuracy and smoothness of
welds accomplished using orbital welding
provided the right results.
Because the pusher mechanism on the
Definox pigging system contains a seal
that both pushes and ensures no material
back-flow, it became even more critical to
consistently produce high quality weld joints.
The weld on the interior tube faces could
tolerate no imperfections, and had to be
perfectly smooth, to prevent damage to the
seal when it passes welds in the pipeline.
Guidelines from the European Hygienic
Engineering & Design Group (EHEDG)
even advise the use of orbital welding
in pharmaceutical and food processing
equipment. The guidelines (released in
1991/1992) specified the interior finish (RA,
maximum 0.8µ), joint shape, form, design,
material, type of connection, and type of
seals. In addition to the EHEDG guidelines,
Definox complies with the US FDA A3
regulation, a strict USDA requirement for
which the company has determined it is
better to use orbital welding.
Definox believe the solution of orbital
welding has been consistently met
through the use of Polysoude’s equipment,
particularly with the PC 300 TR welding
head. In this mechanized welding set-up
– consisting of a column and boom, torch
assembly, turntable and wire feeder – the
part is fixed to the rotating turntable, and
filler wire is used during the application.
Polysoude SAS – France
Fax: +33 240 681 188
Email:
Website:
Definox – France
Fax: +33 2 40 67 89 00
Email:
Website:
Orbital welding essential in custom valve manufacture
Kent Corporation, USA, offers a full line
of Burrmaster and Buckeye deburring
machines for tubing, solids, and extrusions.
The company has just launched a new
model in its Burrmaster range.
The Burrmaster Model 10 for large OD,
short length tubing automatically deburrs
both ends of the tubing simultaneously, for
high production rates. The machine features
quick adjustment mechanisms with built-in
scales for quick and easy changeover.
The Model 10 is capable of deburring
tubing from 1.7" to 4.756" OD, with lengths
from 2.5" to 60", and wall thicknesses from
0.125" to 0.750". A special disc transfer
system enables tubing that is larger in OD
than the length to be deburred, and the
machine can achieve rates of up to 1,200
pieces per hour.
Kent Corporation – USA
Fax: +1 440 237 5368
Email:
Website:
New de-burring machine for large OD pipes
› Kent Corporation’s Burrmaster Model 10