Environmental
Considerations
|
The
first consideration is the type of liquid, temperature
and pressure to which the switch will be subjected.
Madison manufactures liquid
level switches in
various styles, in a variety of materials, to
cover a broad
range of conditions. Following are some basic
recommendations for selecting the proper liquid
level switch material
for your application.
|
| Material |
Application |
| 316
Stainless Steel (SS) |
For
high-temperature (to 300°C), high-pressure
(to 300 PSIG) and corrosive conditions. Commonly
used in food processing, medical, heating and
cooling equipment. |
| Polypropylene
(PP) |
For
acidic conditions, such as found in electroplating
and metal cleaning. Another choice for lower-temperature
(to 105°C) food processing applications
(Madison Company uses only polypropylene that
is FDA-approved for food contact). Also a good
choice for general-purpose applications in
commercial or consumer appliances and equipment. |
| Polysulfone
(PSU) |
A
hydrolysis-resistant material for continuous
use in hot water and steam, at temperatures
up to 148°C. High chemical resistance to
acidic and salty solutions and good resistance
to detergents. Commonly used for analytical
instrumentation, medical devices and semiconductor
process equipment components. Food-grade material
available with FDA, NSF, 3A-Dairy and USP Class
VI compliance, upon request. |
| Brass |
The
selection for petroleum-based liquids, such
as lubricating oils, gasoline and diesel fuels.
Widely used in storage tanks of vehicles, generators,
transmissions and hydraulic systems. Other
uses are in lubrication, recovery, refining
and fuel processing equipment with temperatures
up to 130°C. |
| Buna-N
(Nitrile) |
Suitable
for use with aromatic hydrocarbons, dilute
acids and bases with a temperature range of
-50°C to 120°C. Applications include fuel tanks,
transmissions and hydraulic systems. |
PBT
(Polybutylene
Terephthalate) |
A
strong and highly crystaline plastic featuring
good dimensional stability. Generally serves
where temperature resistance and permeability
are
not important. Ideal for applications such
as fuel and hydraulic systems with continuous
service at 120°C.
Please note: PBT is not suitable for use
in temperatures above 130°C. |
| Kynar |
Chemical-
and solvent-resistant properties make this
material a problem solver for many applications.
Its high purity nature is ideal for food handling
and sensitive laboratory or test equipment
with temperatures up to 105°C. |
| PTFE
(Teflon®) |
This
material is ideal for acids, alkalis, oils
and gasoline applications where temperatures
are up to 260°C. Temperature-stable and
chemical-resistant, with a very low coefficient
of friction. |
|
Madison Company also manufactures selected switch
models in a combination of materials that are available
from stock or in a custom, build-to-order configuration.
Once
a suitable material has been selected, the type
of switch and configuration of actuation points,
fittings and wire terminations are the next considerations.
Madison Company stocks a full line of standard
products
that can meet the requirements of many applications.
For specific designs, Madison can custom build,
to order, switches with an infinite number of variations
and options.
Teflon® is
a registered trademark of E.I. du Pont de Nemours
and Company |
|
| Turbulence |
| Intensive
agitation of liquid, boiling fluids and surging
due to large inflows of liquid can all cause
turbulence and erratic float switch operation.
This problem can be eliminated by the use
of slosh shields with adequately-sized fluid
and vent holes, as illustrated here. Available
for vertical, horizontal (side-mounted) and
multi-point switches with full-size or miniature
floats, these slosh shields can be supplied
in stainless steel, brass, polypropylene,
PBT or Kynar. |
 |
|
|
| General
Product Guide – Selected Standard Switches |
| IN STOCK |
Build to Order |
Typical Applications |
| Mounting: |
Side Mount |
Vertical Mount |
| Material Type |
Single Thread |
Dual Thread |
Full-Size
Float |
Miniature Float |
Submin.
Switch |
Multi-Point
Switch |
| Standard
Switch |
Power
Reed Switch |
| 316 Stainless
Steel |
M5010
M5970
|
M5900
M5910
M5920 |
M5600
M5917
(others) |
M5600-PR
(others) |
M5000
(others) |
N/A |
M5602
M5002
(w/ options) |
High
temperature,
High pressure,
Corrosive conditions |
| Brass &
Buna-N |
M4010 |
N/A |
M4300
(others) |
N/A |
M4500
(others) |
N/A |
M4302
M4502
(w/ options) |
Lubricating
oils,
Hydraulic fluids,
Gasoline and diesel
fuels |
| PBT & Buna-N |
N/A |
N/A |
M7800
(others) |
N/A |
M7000 |
N/A |
N/A |
All
Plastic,
Lubricating oils,
Hydraulic fluids,
Gasoline and diesel
fuels |
| Kynar |
M9750 |
M9700 |
M9800 |
N/A |
M9000 |
N/A |
M9802
M9090
(w/ options) |
Chemical
resistant,
High-purity applications |
| Polypropylene |
M8750
M8790
M8725 |
M8700
M8740 |
M8800
(others) |
M8800PR
(others) |
M8000
(others) |
M3326 |
M8802
M8080
(w/ options) |
General
purpose,
FDA approved for food use,
Acidic
conditions |
| PBT (Polybutylene
Terephthalate) |
M7750
M7790
M7725 |
M7700
M7740 |
N/A |
N/A |
N/A |
N/A |
N/A |
All
plastic, Lubricating oils, Hydraulic fluids,
Gasoline and diesel fuels |
|
N/A - Not Available
Slosh Shields for turbulence protection available
on most switches.
Other material combinations, submersibles and specialty
switches are available. |
|
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of page | Reference] |
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