energy sector
Hunting Cromar, a major international force in the oil and gas
industry has been growing rapidly and investing in new
equipment, since its acquisition by Hunting plc.
Lathes at home in oil country
Wireline valve
manufactured by
Hunting Cromar
A variety of oil
industry parts are cut
on the Mori Seiki machine
THE Bridge of Don (Aberdeen) based firm
Hunting Cromar makes well service technology products.
These include blow out preventer valves, lubricators, and
stuffing boxes which fit at the top of the wellhead
christmas tree, as well as down hole equipment such as
pulling tools, hydraulic jars and spring jars. Technical
Manager David Wallace sets the scene: ‘The specification
of the equipment varies according to the size of the well;
deeper wells can operate at 15,000 psi. We have a huge
range of customers across Norway, the Far East, Europe
and the USA, and although items such as gauge carriers,
which monitor flow and temperature, may stay down the
hole for 15 years, most oil field equipment needs to be
replaced on a continuous basis. Additionally, new wells
are coming on stream all the time, which has enabled us
to increase sales in the last two years, making investment
in the very best technology a high priority.’
This technology includes metal cutting capacity; Gil
Reid, Production Manager, was responsible for selecting
replacement lathes, picking two Mori Seiki SL403
machines for their power and rigidity. He says: ‘I was
impressed with the speed - rapid movement is much
faster than our previous machines, and tool indexing is
superbly quick.’ Parts are in 4140 carbon steel and
410/420 chrome stainless round bar; sizes vary from 6 to
14.375 inches diameter and can be up to 30 inches long.
Typically, 75% of the material is removed and batch sizes
are just one or two components, so rapid material
removal is important. Reid continues: ‘We can take 0.25
inch cut with a 20 thou feed, yet the Mori Seiki’s 30kw
motor is only registering 25% load. With our old
machines, the motor would have overheated if we had
tried to do the same.’ Efficiency improvements are
already between 10 and 20% higher with the new SL403
machines, and payback is anticipated within 16 months.
Rigidity has resulted in lower vibration levels, which
helps Hunting Cromar to achieve the finish and accuracy
it requires. Explains Reid: ‘ O-ring seals need to withstand
32 MWP january 2008
22,500 psi, so finish is critical. With our skilled operators
we find it easy to achieve 0.08μm. The strength of the
machine is in its construction, as it weighs 14 tonnes
compared with the nine tonnes of our previous machine.’
The 10 station turret, fitted with Kennametal fixtures,
enables 80% of parts to be cut without exchanging tools.
Where exchange is necessary, tools can be changed in
seconds, along with the new tool offset number. The
company operators are all skilled machinists who use
the Mapps III system to programme each new part, and
they have found the transition to the new software
relatively easy. In addition, they particularly like the
Mori Seiki Tool Eye, which makes it possible to rapidly
set new tooling, as well as features for controlling feed
and speed during roughing and parting off cycles, to
optimise cutting conditions. Mike Davidson, Machine
Shop Manager adds: ‘We train all our own machinists.
Currently we have five trainees shadowing our skilled
operators to build expertise within our workforce. The
new Mori Seiki machines will play a crucial role in
retaining valuable staff by providing them with
increased job satisfaction.’
To produce a new range of quick lock systems, Hunting
Cromar is also taking delivery of a Mori Seiki NL 2500 SY
700. Batch sizes will be 10 or more, and parts require both
milling and turning. Again, Gil Reid selected the machine
for its rigidity, speed and one hit capability. Furthermore,
having one control system for all the lathes will simplify
programming for his operators. Reid adds: ‘Payback on the
NL is anticipated within six months.’
Hunting’s Badentoy site, on the other side of Aberdeen,
also uses Mori Seiki machines for producing oil country
tubular goods; production entails threading operations on
steel pipes which can be up to 20 inches in diameter and
48 feet long. Amongst the 13 Mori Seiki machines, the
SL10 has a 20 inch bore to suit the largest pipe sizes. All the
machines operate 20 hours per day, 6 days per week, and
the company has just purchased two new Mori Seiki
SL603Ds to replace SL8 machines which have been
running continuously since 1989. Production Manager
Craig Falconer says: ‘The 20 inch pipes have a welded seam
down the length, so there is a considerable out of balance
force as the pipe rotates, and there is an interrupted cut
each time the tool cuts across the weld. Not only is the
Mori Seiki the only machine available with sufficient
capacity for our oil industry products, but its toolpost has
the rigidity to cope with these harsh cutting conditions.’
Gil Reid concludes: ‘The Mori Seikis are the life blood
of the company; every assembly requires parts which go
through the machines. Our business is growing rapidly
so we are heavily dependent on their reliability and we
are confident that they will do the job.’
www.moriseiki.co.uk
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