remote seal type differential pressure transmitter for high
temperature with low cost
ATseries pressure transmitter with remote seal device, constitutes
a remote pressure transmitter.
The remote transmitter can avoid the measured medium directly with
diaphragm contact transmitter.
The remote seals can be fitted to AT3351/1151 Series transmitters for GP/AP/DP.
• The medium is corrosive and requires diaphragm materials in the transmitter which are not available.
• The temperature of the medium is outside the limits(high temperature or freezen) specified for the transmitter and the transmitter needs be isolated .
• The medium is highly viscous or contains solids which would easy to block the measuring chambers of the
• The medium tends towards polymerization or crystallization when using the lead pressure tube.
• The process requires quick-release remote seals and fast cleaning .
Design and Construction
Remote device assembly consists of a transmitter, one or two remote seals, an appropriate transmission liquid, and a
connection element between the transmitter and remote seal (direct mounting or
There are many kinds of structures and materials available, remote
device assembly welding structure reliability. Low volume design in liquid filled cavity, in order to reduce the influence of
environment temperature, according to the requirements of users,
charging conventional silicone oil using temperature range (- 40 ~
149) ℃; filled silicone oil with high temperature using temperature range
(15 ~ 315)℃ (at the request of environment temperature is more than or equal to
10 DEG C. Generally to increased the tropical tipe outside the capillary tube in North cold environment.
Remote device maximum working pressure is the user to select remote
transmission device ratings; working pressure shall not be less
than 350 kPa (absolute pressure). For corrosive medium, select the
isolation diaphragm material, Please refer to Appendix 3 (only for the role of the user selected reference).
Measuring object: high temperature corrosion or viscous liquid
Accuracy: 0.1% , 0.2% , 0.5%
Measurement range: 6kPa ~ 20MPa
Measurement type: single/double flange, flange clamp type (specification, size can be
customized according to customer requirements).
Output signal: 4 - 20mA, intelligent 4 - 20mA HART communication protocol .
Working voltage: 24V DC; 12 ~ 36V DC; 18.5 ~ 45V DC; 220V AC, 50HZ.
Filling medium: ordinary silicone oil, silicone oil resistant high temperture, fluorinated oil (selection according to customer’s site temperature).
Diaphragm material: 316L stainless steel, Monel, Hastelloy Has-c,
tantalum (special specifications can be customized according to
Explosion-proof grade: ordinary type; flameproof intrinsically safe ExiaIICT6 ExdIIBT4; electrical connections: direct connection, lead, explosion-proof
terminal (special specification according to customer demand for
Display: a variety of display options (mA, Pa ,0- 100%, density, liquid level and so on).
With the EEPROM, without loss of data when power off.
Table 1 Differential pressure / pressure transmitter with remote device
AT 3351 Series Pressure
Remote Seal System Transmitter(DP:Double flange;GP:Single flange)
(0~100)% Linear pointer table
3 1/2 LCD Digital Display
3 1/2 LED Digital Display
LCD Intelligent Display
(4~20)mADC Linear,Analog signal
(4~20)mADC Intelligent, With HART Protocol Communication
Flange material Diaphragm material
316L stainless steel 316L
316L stainless steel Hastelloy C-276
316L stainless steel Monel
316L stainless steel Tantalum
Tube bending support
Plate bending support
Tube / plate mounted flat bracket
AT3351 DP 4E 1 P M5 S 22 B1
AT 3351Series Remote Seal System Different pressure transmitter;
Range 0~40KPa(4E); Accuracy :0.5% Intelligent LCD Display,
(4~20)mADC With HART Protocol Communication;
Diaphragm material:316L; Tube bending support
Table 2 Remote System Filled Characteristics
Temperature expansion coefficient (1/℃)
Viscosity in 25℃(mPa·s)
High temperature silicone oil
1. The temperature limit will be lower in vacuum.
2. If the pressure exceeds 590kPa, the temperature can be up to 315℃, otherwise, it should be less than 315℃. When the high temperature silicone oil is filled, it is required that the
environment temperature of the flange joints, capillary, transmitter body and other parts of
the high temperature silicone oil contacted should below in 10℃. In the cold condition of the north, the capillary should be covered by the tropical, so that the oil can not solidify.
3. Order code behind of the capillary Code