Document ID: EPA-HQ-OW-2004-0002-0608
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2004-11-30T05:00Z

7545
Breen
Street
­
Houston,
Texas
77086
Phone:
(
281)
445­
2243
­
Fax:
(
281)
445­
4061
Kal
Karmous
GSF
 
Operations
Support
7­
19­
02
Dear
Sir,

Regarding
your
query
of
possible
EPA
regulations
reducing
fluid
velocity
to
.5
feet
per
second
at
fluid
entry
point,
we
advise
the
following
solution.

Current
fluid
velocity
averages
around
3.5
feet
per
second
for
the
majority
of
GSF
rigs.
To
reduce
this
velocity
each
rig
would
be
required
to
install
new
caisson
with
a
minimum
inner
diameter
of
approximately
40".
Obviously
the
cost
impact
of
such
a
task
would
be
high
and
would
depend
on
each
shipyard
utilized
for
day
rates
and
material
cost,
not
to
mention
down
time
for
the
rig
itself.
Even
worse,
the
current
rigs
in
your
fleet
were
not
designed
for
such
large
caisson
pipe
and
would
probably
require
major
design
changes
just
to
accommodate
the
required
modifications.

Any
rigs
operating
submersible
motors
other
than
EMU
motors
would
require
adding
a
special
flow
inducer
to
maintain
fluid
flow
over
the
motor
for
cooling
purposes
in
this
larger
caisson.
The
EMU
motor
is
would
with
specially
radiated,
high
temperature
winding
wire
and
does
not
require
fluid
flow
past
the
motor
in
sea
water
up
to
40oC,
104oF.
The
EMU
motors
will
not
require
any
special
adders
if
this
design
change
is
implemented.

Another
possibility
which
may
be
suggested
is
a
screen
on
the
bottom
of
your
current
caisson
to
eliminate
fish
and
sea
life
from
entering
the
caisson;
this
is
not
recommended.
A
screen
would
give
sea
life,
such
as
barnacles
and
sea
grasses
an
attachment
point.
This
sea
life
can
completely
clog
your
caisson
fluid
entry
point,
literally
in
only
a
couple
of
months,
starving
the
submersible
unit
of
water
and
causing
catastrophic
failure
to
your
sea
water
pumps
and
motors.
The
maintenance
nightmare
this
would
create
far
outweighs
the
larger
caisson
solution.

With
Best
Regards
Richard
W.
Draper
S&
N
Pump
Company
richarddraper@
snpump.
com
www.
snpump.
com