2600T SERIES |  PRESSURE TRANSMITTERS |  OI/266/FF-EN REV. E
23
Transmitter housing rotation
To improve field access to the wiring or the visibility of the 
optional LCD meter, the transmitter housing may be rotated 
through 360° and fixed in any position. A stop prevents the 
housing from being turned too far. In order to proceed with 
housing rotation, the housing stop tang-screw has to be 
unscrewed by approximately 1 rotation (do not pull it out) and, 
once the desired position has been reached, retightened.
Figure 25: Housing rotation 
Impulse piping connection for standard 
instruments
In order for the pipes to be laid correctly, the following points
must be observed:
•  The measuring pipes must be as short as possible and free 
from sharp bends.
•  Lay the impulse piping in such a way that no deposits 
accumulate in them. Gradients should not be less than 
approx. 8% (ascending or descending).
•  The measuring pipes should be blown through with 
compressed air or, better yet, flushed through with the 
measuring medium before connection.
•  Where a fluid/vaporous measuring medium is being used, the 
liquid in both measuring pipes must be at the same level. If a 
separating liquid is being used, both measuring pipes must 
be filled to the same level (266Dx and 266Mx).
•  Although it is not absolutely necessary to use balancing 
vessels with vaporous measuring media, measures must be 
taken to prevent steam entering the measuring chambers of 
the measuring equipment (266Dx and 266Mx).
•  It may be necessary to use condensate vessels, etc., with 
small spans and vaporous measuring media (266Dx and 
266Mx).
•  If using condensate vessels (steam measurement), you should 
ensure that the vessels are at the same elevation in the 
differential pressure piping (266Dx and 266Mx).
•  As far as possible, keep both impulse lines at the same 
temperature (266Dx and 266Mx).
•  Completely depressurize the impulse lines if the medium is a 
fluid.
•  Lay the impulse lines in such a way that gas bubbles (when 
measuring fluids) or condensate (when measuring gases) can 
flow back into the process line.
•  Ensure that the impulse lines are connected correctly (High 
and Low pressure sides connected to measuring equipment, 
seals...).
•  Make sure the connection is tight.
•  Lay the impulse line in such a way that prevents the medium 
from being blown out over the measuring equipment.
 CAUTION 
Process leaks may cause harm or result in death. Install and 
tighten process connectors and all accessories (including 
manifolds) before applying pressure. In case of toxic or 
otherwise dangerous process fluid, take any precautions as 
recommended in the relevant Material Safety Data Sheet 
when draining or venting. Use only a 12 mm (15/32“) 
hexagonal spanner to tighten the bracket bolts.