2-21
Each service uses a different impulse piping arrangement to maintain a
single phase of fluid in the piping and ProPlate electronics. For
example, liquid applications must maintain a liquid state and allow
any air or gas formation to travel up and away from the ProPlate
electronics, and gas applications must maintain a gaseous state and
allow the formation of liquids to drain down and away from the
ProPlate electronics.
The piping used to connect the sensor probe and electronics must be
rated for continuous operation at the pipeline-designed pressure and
temperature. A minimum of one-half inch (½-in., 12mm) O.D. stainless
steel tubing with a wall thickness of at least 0.035" is recommended.
Threaded pipe fittings are not recommended because they create voids
where air can become entrapped and have more possibilities for
leakage.
The following restrictions and recommendations apply to impulse
piping location.
1. Impulse piping that runs horizontally must slope at least one inch
per foot (83mm/m).
• It must slope downwards (toward the ProPlate electronics) for
liquid and steam applications.
• It must slope up (away from the ProPlate electronics) for gas
applications.
2. For applications where the pipeline temperature is below 450°F
(232°C), the impulse piping should be as short as possible to
minimize flow temperature changes. Insulation may be required.
3. For applications where pipeline temperature is above 450°F
(232°C), the impulse piping should have a minimum length of one
foot (0.3048 m) for every 100°F (38°C) over 450°F (232°C), which is
the maximum operating ProPlate electronics temperature.
Impulse piping must be uninsulated to reduce fluid temperature.
All threaded connections should be checked after the system comes
up to temperature, because connections may be loosened by the
expansion and contraction caused by temperature changes.
4. Outdoor installations for liquid, saturated gas, or steam service
may require insulation and heat tracing to prevent freezing.
5. For installations where the ProPlate electronics are more than
six feet (1.8m) from the sensor probe, the high and low impulse
piping must be run together to maintain equal temperature.
They must be supported to prevent sagging and vibration.
6. Run impulse piping in protected areas or against walls or ceilings.
If the impulse piping is run across the floor, ensure that it is
protected with coverings or kick plates. Do not locate the impulse
piping near high temperature piping or equipment.
7. Use an appropriate pipe sealing compound rated for the service
temperature on all threaded connections. When making threaded
connections between stainless steel fittings, Loctite PST Sealant is
recommended.
To Next Page
Loading...
