56
Dixon Sanitary 2014
800.789.1718
Diaphragm Valves
Diaphragms
EPDM
Ethylene-propylene elastomer peroxide cured. EPDM is a
specifically developed compound reinforced with a vulcanized
woven fabric inlay and is always manufactured in the molded
open position. This diaphragm construction achieves higher
stability for the diaphragm at elevated temperatures and
pressures. In addition, the woven fabric inlay is vulcanized
over the embedded compressor stud in order to strengthen the
elastomer-metal connection. Thus, the EPDM diaphragm is
ideal for vacuum applications.
PTFE (TFM)
These PTFE diaphragms have been designed and offer the
highest degree of chemical resistance, increased stability,
longer flex life, less porosity, reduced cold flow and superior
performance through temperature fluctuations between hot
and cold and steam sterilization cycles.
MA8 and MA10
The diaphragm dimensions MA8 and MA10 are designed as
one-piece diaphragms: This means that the EPDM back is
bonded with the PTFE.
The diaphragm is always manufactured in the molded open
position. These one-piece diaphragms have less surface area
and are subject to shorter linear strokes which explain the
excellent performance that has proved itself over time.
MA8 diaphragm incorporates an elastomer button for assembly
with the valve operating mechanism. The MA10 utilizes a
threaded stud assembly with the valve operating mechanism.
Both these features eliminate the potential for point loading at
the center of the diaphragm.
MA25 to MA100
The diaphragm dimensions MA25 to MA100 are designed as
two-piece diaphragms consisting of a separate EPDM backing
cushion and PTFE diaphragm. The diaphragm is always
manufactured in the molded closed position. The advantage of
this design for the MA25 to MA100 is that the diaphragm is in
its molded shape while in the closed position of the valve. This
reduces the force to close the valve and increases the life of
the diaphragm.
In the two-piece diaphragms the threaded stud connection
is embedded in the PTFE of the diaphragm. To eliminate
the potential of point loading at the center of the diaphragm,
a floating suspension connection to the valve operating
mechanism is utilized.
Code
18
30
51
44
MA
8-100
8, 25,
40, 50 10
25-100
Material
EPDM
PTFE/EPDM PTFE/EPDM
Design
One-piece
Molded open
One-piece
Molded open
Two-piece
Molded closed
Temperature
Range
(
°C)
-40
to 150 *
-20
to 150
-20
to 160
(
°F)
-40
to 300 *
-20
to 300
-20
to 320
*
The listed temperatures may apply to clean steam sterilization
protocols and may not apply to continuous steam service. Upon
request, other diaphragms are available with other materials, bigger
sizes and for high temperatures up to 350°F (175°C).
MA8
Molded Open
EPDM
PTFE/EPDM
one-piece
MA10
Molded Open
EPDM
PTFE/EPDM
one-piece
MA25-80
EPDM
Molded Open
PTFE/EPDM
two-piece
Molded Closed
MA100
EPDM
Molded Open
EPDM
Molded Closed
F