Delta Controls D-Series TDSSP - Manual (Page 2)

www.delta-controls.com
D-Series
Models: S-P
Application
The diaphragm seal is a pressure transmitting, diaphragm-type device. The pressure signal is sent to the cooperating
pressure measuring device (pressure transmitter, pressure gauge) through manometric liquid filling the space between the
separating diaphragm of the seal and the pressure measuring device. The diaphragm seal task is to isolate the pressure
measuring device from damaging impacts caused by either medium or installation:
s Low or high temperature, increased viscosity, and impurities
s Vibrations of the installation (remote diaphragm seal)
Measuring Ranges
Important:
- contact face in diaphragram seal DN50 have a milled slot for a gasket (acc. to DIN 2512 FormN). Version without any
slot available on request. (acc. to DIN 2526 FormE)
- standard outlet capillary from flange:
direct mounted diaphragm seal - axial
remote mounted diaphragm seal - radial
Recommended minimum measuring range (bar),
depending on the type of the set: pressure measuring device - diaphragm seal
Pressure
measuring device
Diaphragm
seal type
Diaphragm seal version
DN50 / 2’’ DN80 / 3’’ DN100 / 4’’
Smart
transmitters ∗
direct 0.25 0.1 0.1
remote (2 m) 1 0.25 0.25
DPCE-28
direct 0.1 0.1 0.1
remote (2 m) 1 0.25 0.25
Additional absolute zero error resulting from ambient temperature fluctuations,
depending on the type of the set: pressure transmitter - diaphragm seal
Diaphragm seal type Absolute zero error per 10°C for the diaphragm seal
DN50 / 2’’ DN80/ 3’’ DN100 / 4’’
direct 0.5 mbar 0.4 mbar 0.4 mbar
remote (2 m capillary) 3 mbar 1 mbar 1 mbar
Temperature range of measured medium
Remote diaphragm seal Direct diaphragm seal
Manometric liquid Underpressure measurements Overpressure measurements
high -temperature (DC) -10...150°C -10...315°C -30...150°C
low-temperature (AK) not recommended for measure ment
of pressures < 0.5 bar ABS
-60...200°C
Note: When operating with an amb ient temperature of < -15°C, heating of capillaries filled with DC fluid is recommended.
Maximum pressure for PN40 – 40 bar
Maximum pressure for ANSI 150 – 150 psi
Material of diaphragm and flange 316Lss
Special versions
- Other standard ANSI or DIN
- Filled with edible oil (medium temp. -10...150°C)
- Direct diaphragm seal for medium temp. over 150°C
- Others
Recommendations
The essential metrological problem with diaphragm seal operational use is the absolute thermal zero error, which results
from the thermal expansion of the manometer liquid. The expansion effect must be compensated for by the separating
diaphragm’s flexibility.
To minimise this effect, it is advisable to:
s Use capillaries which are as short as possible - in this way, the volume of manometer liquid will be reduced
s Use seals with greater diameters in order to maximise the flexibility of the separating diaphragm
s Place the capillaries in places in which the temperature fluctuations will be minimal
*The ranges given in the table for the smart transmitters should be taken as set ranges
An additional zero error, resulting from
temperature fluctuations in a medium,
depends on the temperature gradient in
the oil-based diaphragm sealing
system. The error value is, in any case,
significantly smaller than the error value
shown in the table.