Burkert Type 2731 - Manual (Page 25)

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Remove the actuator from the body.
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Unscrew old diaphragm. If attachment is with a bayonet catch,
remove the diaphragm by rotating it through 90°.
→
Install new diaphragm.
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Align diaphragm.
the marker flap of the diaphragm must be perpendicular to
the direction of flow (see “Fig. 16”)!
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Place actuator back on the body.
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Lightly cross-tighten the body screws / body nuts without pres-
surization until the diaphragm is between the body and actuator.
do not tighten body screws / body nuts
yet.
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Pressurize upper pilot air port of the actuator with compressed
air (5 bar) (see “Fig. 16”).
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Actuate the diaphragm control valve twice.
→
With pressurization tighten the body screws / body nuts to the
permitted tightening torque (see “Tab. 11: Tightening torques for
diaphragms”).
tightening torques
Orifice dn
(diaphragm
size) tightening torques for diaphragms [nm]
epdm
ptfe
65 20 30
80 30 40
100 40 50
Tab. 11: Tightening torques for diaphragms
13 replaceMenT parTs
WarNiNg!
risk of injury when opening the actuator!
The actuator contains a tensioned spring. If the actuator is
opened, there is a risk of injury from the spring jumping out!
▶ The actuator must not be opened.
CauTioN!
risk of injury and/or damage by the use of incorrect parts!
Incorrect accessories and unsuitable replacement parts may
cause injuries and damage the device and the surrounding area.
▶ Use only original accessories and original replacement parts
from Bürkert.
The diaphragm is available as a replacement part for the piston-
controlled diaphragm control valve Type 2730 / 2731.
The insert is also required when changing from a PTFE dia-
phragm to an elastomer diaphragm (order number: 648864,
for installation see “7.4 Insert”).
If you have any queries, please contact your Bürkert sales
office.
25
Replacementparts
english
Type 2730 / 2731 DN 65-100