MODEL
TPC PRESSURE CORRECTOR ADD-ON OPTION
FOR LEVEL MEASUREMENT IN PRESSURIZED UNVENTED TANKS
Download the Delta Controls
Model TPC Detailed Datasheet
Features
- Provides D/P Cell Level
Benefits Without Their Problems
- The Diaphragm Seals And
Capillary Tubing Commonly Required By D/P Cells Are Not Needed
- No Need For A Troublesome
"Wet Leg" Reference, No Wet Leg To Get Plugged Or to be Emptied
By Evaporation
- Adds On To A 550 Head
Pressure Level Transmitter the Separate Modular Electronics
- Powered By The Basic
2 Wire Level Loop; Additional Power Supplies, Wires, Etc. Are Not Required
- An Oil Filled 316-L Or
Hastelloy"C"® Diaphragm Protects The Silicon Pressure Sensor
Element
- Piping, Valving, And
Installation Is Simplified
- Can Work Under Vacuum
and/or Pressure Conditions
- Works On Hazardous Materials
Where Both Sensing Connections Must Be Through The Top Of The Tank
- Undisturbed By Agitation,
Demisters, Or Heating
- Can Be Used To Measure
Density Of The Liquid
- Great For Tanks With
Gas Blanketing Back Pressure Relief Valves, Or Disc Vents
- Low Installed Cost And
Good Accuracy
- External To The Vessel
Impulse Line
- Maintenance Is Not Required
Description
The Delta
Controls Model TPC works in conjunction with, and connects to the housing
of a Series 550 Level Transmitter. The Series 550 head pressure level transmitters
measure the height of liquid in a tank by measuring the pressure at the bottom
of the tank. That pressure is linearly proportional to the height of liquid
above the transmitter sensor in an open tank. Any pressure in the gas space
of a closed tank is additive to the pressure measured at the bottom of the tank.
The Model TPC corrector senses the gas space pressure and electronically subtracts
it from the total pressure sensed by the level sensor located at the bottom
of the tank. The formula is:
PTB - PGS = PHD (Which
is due to the liquid level in the tank)
where
PTB = Total Bottom Pressure
PGS = Pressure in gas space (positive or vacuum)
PHD = Pressure at bottom of tank due to liquid height
The bottom and top tank
pressures are linked electronically rather than mechanically with a wet leg.
The TPC avoids the plugging, condensation, and evaporation problems associated
with conventional D/P cell wet legs and impulse piping. The absence of a wet
leg also makes a purge system unnecessary when the liquid carries entrained
solids. The TPC can also be used to measure the density of a liquid in a vented
or pressurized tank. The top sensor is moved down in the tank so that it will
always be covered by the liquid. The difference in pressure measured between
the two elevations is proportional to the density of the liquid. This setup
also allows the elevation position of an interface to be transmitted. Seals,
capillaries, purging, air bubbling, etc. are not required.
Specifications
- Service:
Used with Delta Controls Models 552, 562, 563, 564, 566, 572, and 592 for
measuring level in unvented tanks
- Action:
Corrects for gas space pressure variations
- Supply Power:
None required, works off of the 2 wire level signal loop, Intrinsically safe
- Protective Devices:
Integral voltage and noise suppressers
- Electronics Location:
Mounted in the level transmitter housing, and is part of the module
- Over Pressure:
2X Range, 35 PSI (2.5 Bar) minimum without damage; 3X Range, 1000 PSI (70
Bar) minimum without rupture
- Temperature
Range:
- -20 to +220°F (-30
to 105°C) Sensor
- -20 to +180°F (-30
to 85°C) Electronics Module
- 30 to +130°F (0 to
55°C) Compensated (Higher Available)
- Accuracy:
&plusm;0.25% F.S. or better
- Thermal Error:
&plusm;0.02% F.S. / °F (0.01% F.S. / °C) maximum
- Barometric Effect:
None
- Hysterisis:
None measurable
Third Party
Approvals:
- C.S.A. (Canada); NRTL/C
(USA)
- Intrinsically Safe
- Explosion Proof
- Environment Proof
- 3A Sanitary
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