Watson-Marlow
Tubing and Bredel Hoses
- the heart of the pump
Watson-Marlow
Bredel pumps use either hoses
which are reinforced against
high pressure, or tubing which
is unreinforced for lower pressure
duties. For accurate metering
or dispensing and for long life,
both must be be made with tightly
controlled formulations and
dimensions. Only Watson-Marlow
tubing and Bredel hoses are
made for use in Watson-Marlow
Bredel pumps.
Watson-Marlow
Tubing
Available
in seven different materials
and twenty-two different sizes,
from 0.13mm to 40mm, the range
of Watson-Marlow Tubing enables
customers to configure their
peristaltic pumps for specific
applications.
How to choose the right tubing
material.
Tubing
Selection Guide
The best way to select a tube
is to first decide which materials
are chemically suitable, and
then choose the one which best
meets the physical demands of
the application. For maximum
tube life, use a large bore
tube at low speed.
For maximum flow rate use the
largest tube at maximum speed.
For maximum accuracy, use a
small bore tube at maximum speed.
Suction lift depends on the
tube restituting fully before
the advance of the next roller.
If it does not, the flow rate
will be reduced. For maximum
suction lift or pressure, use
the smallest practicable bore
size of tubing and run the pump
at the slowest possible speed.
Always make an immersion test
before choosing a tube material
for critical applications. Immerse
a short length of the tubing
(always available from Watson-Marlow
Bredel or its distributors)
in a closed container of the
fluid for 48 hours, and then
examine it for signs of attack,
swelling, embrittlement or other
deterioration.
The tubing is as important as
the pump because:
- Its
restitution creates suction
lift
- Its
strength resists pressure
- Its
flex resistance determines
pumping life
- Its
bore decides the flow rate
- Its
wall thickness controls pumping
efficiency.
Ordinary
tubing is not designed for
peristaltic pumping, and
only Watson-Marlow precision
pump tubing will give the
best results in a Watson-Marlow
pump. The results of using
any other tubing are unpredictable,
and may jeopardise your
process.
Bredel
Hoses
Bredel's
innovative hose design and construction
has created the benchmark in
hose performance and life. The
unique design ensures that compression
forces are evenly applied, and
the enormous restitutional ability
of the hose creates powerful
suction handling and accurate
metering capabilities.
High-precision
machined hose element
At
the heart of all Bredel pumps
is a remarkable composite reinforced
hose. The hose is constructed
from high-quality compounded
rubbers reinforced with four
(two in the case of the SP10
and SP15 hoses) individual layers
of braided nylon, and finished
by high-precision machining.
Because
rubber is incompressible, nothing
is more important to hose pumping
that acurate control of the
hose dimensions to ensure that
the occlusion of the hose is
exactly right:
- Over-occlusion
of the hose stresses both
pump and hose, reduces hose
life, and places unplanned
loads on the pump bearings.
- Under-occlusion
results in loss of pump efficiency
and damaging back-flow, which
also reduces hose life.
Bredel
is the only hose pump manuacturer
to machine its own hoses,
and no other manufacturer
can match Bredel's experience
of configuring pump and
hose to precisely meet the
flow, pressure and temperature
characteristics of any application.
