Honeywell SmartLine ST 700 - Transmitter Location; Table 8 - ST 700 Standard Transmitter - Suggested Connection Locations

Page 24 ST 700 SmartLine Pressure Transmitters User’s Manual Revision 13
4.5.2 Transmitter Location
The following are suggested connections based on what is being processed by the system.
Table 8 – ST 700 Standard Transmitter - Suggested Connection
Locations
Process
Suggested Location
Description
Gases
Above the gas line.
The condensate drains away from the transmitter.
Liquids
Below but near the elevation of
the process connection.
This minimizes that static head effect of the
condensate.
Level with or above the process
connection.
This requires a siphon to protect thetransmitter from
process steam. The siphon retains water as a fill fluid.
1. For liquid or steam, the piping should slope a minimum of 25.4mm (1 inch) per 305mm (1 foot).
2. Slope the piping down toward the transmitter if it is below the process connection to allow
the bubbles to rise back into the piping through the liquid.
3. If the transmitter is located above the process connection, the piping should rise vertically
above the transmitter. In this case, slope down toward the flow line with a vent valve at the
high point.
4. For gas measurement, use a condensate leg and drain at the low point (freeze protection may
be required here).
ATTENTION Care must be taken when installing transmitters on hot processes.
The operating temperature limits for the device (as outlined in Table 5) must not be
exceeded. Impulse piping may be used to reduce the temperature of the process that comes
into contact with the transmitter meter body. As a general rule there is a 56C drop (100F)
in the temperature of the process for every foot of ½ inch uninsulated piping.