digital differential pressure transmitter,ISO9001 Approval,automation instruments supplier for (CNPC) and SINOPEC

digital differential pressure transmitter, ISO9001 Approval.

My company is automation instruments supplier for China National Petroleum Corporation (CNPC) and China Petroleum & Chemical Corporation (SINOPEC).

Application

1. In petroleum, petrochemical, chemical industries.

  * Operating with throttle orifice. Supply accurate flow measurement and control.

  * Measuring the pressure of piping and liquid level of storage tank.

2. In electric power, coal gas and other civil projects.

  * Being used in high stability and precision measuring occasion.

3. In paper-pulp and paper-making industries.

* Being suitable for aggressive and corrosive liquid.

4. In Steel, nonferrous metal and ceramic industries

  * Be suitable for furnace chamber pressure measurement, etc, in requiring high stability and precision measure occasion.

  * Be suitable for requiring stable measurement occasion under strict control conditions (temperature, humidity and so on).

5. In mechanism, shipbuilding industries.

  * Be suitable for requiring stable measurement occasion under strict control conditions (temperature, humidity and so on).

Principle of operating

Through the isolating membranes at both sides and the filled liquid, the process pressure is transmitted to the core measure membrane inδchamber. Core membrane is a tensioned elastic element. It produces corresponding deformation and displacement under the acting from the pressure at both sides. The displacement is in direct proportion to the differential pressure. The maximum displacement is about 0.1mm. This displacement is converted into the differential capacitance between the capacitance polar plates. Then through electronic circuit, differential capacitance is converted into two-wire 4--20mA DC output signals.

Please find the attached figure in the right.

Main technical parameters

Operating voltage: 24V DC

Precision: ±0.1%

Input impedance: >100MΩ

Suitable fluid: liquid, gas and steam

Measuring range: see table 1

Service voltage: 24V DC

Output signal: 4--20mA DC

Power entrance: M20×1.5

Ambient temperature: -20--70 (for common transmitters)

                  -15--70 (for the transmitters with field indicators)

Power influence: less than ±0.005%/V of output range

Vibration influence: when vibration frequency at any direction is 200Hz, the error is 0.05%/g of the maximum range. Measuring code is 2. (for micro-differential transmitter, the error is 0.25%/g).

Load influence: when the power supply is stable, there is no load influence.

Mounting position influence: when the operating diaphragm is mounted vertically, zero system error is no more than 0.24kPa. This error can be removed through adjusting zero, there is no influence for measuring range.

Stability: Under the condition of temperature 28, the maximum static pressure 6.9MPa, the measuring ratio 1:1, the accuracy will maintain within ±0.2%FS during a whole year.

Intelligent functional parameters:

1. Two-wire output analogue signal superimposed with HART digital signal. User can select linear output signal or squire root output signal.

2. Measuring range and zero point can be adjusted by using local button or remotely with HART communication.

3. Fault alarm by self-diagnosis function.

4. With transmitter state write-lock function. Damping can be set.

3351DP differential pressure transmitter

The transmitter is one kind of capacitance transmitter based on the differential capacitance principle. The input pressures are 06kPa, 040kPa, etc. separately.

Suitable fluid: liquid, gas and steam

3351DR differential pressure transmitter

The transmitter is one kind of capacitance transmitter based on the differential capacitance principle, input pressures are 050-1000Pa separately, output simulation signal is 4-20mA Dc.

Suitable measured fluid: liquid, gas and steam.

3351HP differential pressure transmitter

High static pressure transmitter can measure differential pressure under 32MPa. It has pressure resistance and process protection under 32MPa to ensure its good reliable application in high static pressure system.

Suitable fluids: liquid, gas and steam.

The minimum pressure for 3351 capacitance pressure transmitter to measure is 1KPa, and It can be shifted to negative pressure transmitter.

Suitable fluids: liquid, gas and steam.

3351AP differential pressure transmitter

3351AP transmitter is a kind of absolute pressure transmitter which can realize to measure absolute pressure in deaerating system, distillation tower, evaporator and crystallizer, etc. Allowable over pressure is less than 10MPa.

Suitable fluids: liquid, gas and steam.

3351LT flanged liquid level transmitter

3351LT flanged liquid level transmitter respectively adopts ANSI flange standard. The size of flange is 3 or 4. The grade is 150lb or 300lb. For the flange dimensions, pleas see the following table. If consumer wants to use GB9116-88 standard, please note it and DN=80,100 PN=2Mpa.

The wetted membrane materials are 316L, hastelloyC-276, monel, tantalum, etc. We usually supply flange of 3 150lb with wetted membrane material 316L without special statement from the customer.

3351DP/GP differential pressure/pressure transmitter with remote device

3351DP/GP transmitter becomes 3351DP/GP remote transmitting differential pressure/pressure transmitter, when it is equipped with remote transmitting device.