Welcome to the first in a new series about
the disasters that can happen in a maintenance environment, I'll cover a few
case studies and look at what went wrong, ok... I’ll tell you about what
happened and you can have a good laugh.
I used to be the maintenance manager at a
CD,DVD and Bluray factory, at one point we had to install 2 new DVD lines. We
got the floor marked out and organised all the subcontractors for the
installation of the services… Air, water, argon, power.
The services for the factory came from a
separate building containing the compressors, water treatment, electrical
cabinets, etc. All this passed over a bridge into the space above the cleanroom,
this space looked a mess, but it was made of load bearing panels. You could walk about without bending over too
much, as long as you minded your head.
So on the big day, we took delivery of over
€1.0M of machines and after getting them all lined up, set about connecting
them.
For the water and air, we used a system of stainless
tubes with crimped connections, 28mm for water and 22mm for air. It is a clever
system, you cut the tubes to length then fit connectors, Ts, angles, threaded
adaptors, etc. These fittings push on to the tube and have a captive o-ring so that
when the joint is crimped together you get a strong leak-proof seal. After
getting everything dry fitted so that it looks good, you can go around with the
crimping tool to permanently fasten everything together. The installation as I
said before was subcontracted as we didn’t have the hydraulic crimping tool to do
it ourselves.
I was still in the clean room when one of
the 2 guys installing the tubes came to tell me they had finished the water and
were going to lunch before starting on the air. The shut of valves at the side
of the machine were closed, but they had opened the valves above the clean room
so we could start connecting everything when
we wanted. It was about 1:30, so I went for some food too.
When I got back everything had gone pear
shaped...
Inside the cleanroom, it was raining. Water
was pouring from between the seals on the roof panels, filling up the
fluorescent fittings and leaking from the filters. The new machines were
getting soaked and everyone was running about shouting.
All I could think was to get everything
turned off before someone got electrocuted as the rest of the lines were still
working. After this, the second priority was finding something to cover the
machines with. A 2.5m x 30m roll of bubble wrap from the warehouse was rushed
in and used to try and cover everything up. Once that was underway, I went
upstairs to find out what had happened.
As I worked my way to the far end of the
space above the clean room (minding my head), it became obvious. One of the fittings
had not been pushed on to the tube correctly before crimping it together, so
the o ring didn’t seal properly. After opening the valve, the 6 bars of
pressure had slowly pushed the fitting off the tube, then proceeded to empty 2
tons of cooling water. As I tried to work my way past the torrent to the valves
to isolate the flow, the low level float switch in the cooling water tank tripped
and the pumps stopped.
In the end we had well over an inch of
water covering the clean room floor with oil slicks around the hydraulic
machines, and floating plastic everywhere. We opened the emergency exits and
started to sweep the water out.
We had a wet vac, but the bucket was only
about 10 litres so it wasn’t too helpful. We borrowed a bigger one and kept at
it.
The next morning after some good work by the night shift, I returned to
find almost everything back to normal except for some persistent puddles caused
by water underneath some machines that was hard to get to.
The installer’s insurance company was
lucky, thanks to the bubble wrap, there wasn't too much damage. A 20KV power supply that was working when it
all kicked off had shorted out, 2 heaters and a couple of HEPA filters had also
given up the ghost. I think the total was less than €20k.
I don’t know if the Installers got paid, although
they did get something... a good shouting at, first from me, then from my boss.
Before the next installation came around, I
ordered a hydraulic crimper and some tubes and fittings. We did all the fitting
ourselves from then on. The price for the crimper and associated stuff was less
than we paid for the 2 guys to come in and fit the tubes in the first place.
