The Yokogawa EJXC80A and EJAC80E Diaphragm Seal System is a specialized pressure measurement solution for applications where the process medium should be isolated from the pressure transmitter. The system combines a Yokogawa pressure transmitter with one or two diaphragm seals, allowing differential or gauge pressure to be measured without exposing the transmitter's pressure-sensing assembly directly to the process fluid.
Diaphragm seals are particularly useful when conventional impulse piping is unsuitable. Yokogawa identifies applications involving high- or low-temperature fluids, highly corrosive or high-viscosity fluids, low-temperature media that can cause impulse-line blockage, toxic fluids, and fluids containing suspended solids that may deposit in impulse piping.
For differential pressure measurement, the EJXC80A can be configured with an EJX110A or EJA110E differential pressure transmitter. The EJAC80E can also be configured as a differential pressure diaphragm seal system using an EJA110E transmitter. For gauge pressure measurement, the systems are available with EJX430A or EJA430E pressure transmitters.
The remote-mount flanged diaphragm seal configuration is available in flush and extended types, allowing the seal geometry to be selected according to the vessel, nozzle, and process connection requirements. Flush seals are available in 1½-inch, 2-inch, and 3-inch sizes, while extended flanged seals are available in 3-inch and 4-inch sizes. Inner diaphragm seal configurations are also available with ½-inch, ¾-inch, and 1-inch connections.
For differential pressure applications, the EJXC80A provides measurement spans from 2 kPa to 14 MPa, depending on the selected capsule and seal configuration. The EJAC80E differential pressure configuration provides measurement spans from 2.5 kPa to 14 MPa. The available gauge pressure configurations cover applications from low-pressure measurement through higher-pressure process systems.
The system is particularly useful for liquid level, density, flow, and pressure measurement where direct process connection could result in measurement problems or damage to the sensing assembly. Diaphragm seals provide a physical barrier between the process medium and the transmitter, helping maintain reliable measurement in difficult process environments.
Yokogawa also provides a compensation capillary configuration for differential pressure applications. The compensation system helps balance the volume and temperature effects of the fill fluid between the high- and low-pressure side capillaries. Yokogawa's comparison data demonstrates a significant reduction in output change caused by asymmetric temperature exposure of the capillary and seal assembly.
Key Features
- Differential and gauge pressure diaphragm seal system
- Yokogawa EJXC80A / EJAC80E configuration
- One or two diaphragm seals
- Remote-mount flanged diaphragm seal options
- Flush and extended diaphragm seal designs
- Compatible with EJX110A / EJA110E differential pressure transmitters
- Compatible with EJX430A / EJA430E gauge pressure transmitters
- Suitable for high- and low-temperature fluids
- Suitable for highly corrosive media
- Suitable for high-viscosity fluids
- Suitable for toxic process media
- Helps prevent impulse piping blockage
- Suitable for media containing suspended solids
- Differential pressure measurement for flow, level, density, and pressure
- Gauge pressure measurement
- Compensation capillary configuration available
- Multiple process connection sizes
- Remote-mounted process connection design
- Flush diaphragm seal options
- Extended diaphragm seal options
- Designed for demanding chemical and oil & gas applications
Differential Pressure Measurement Span
EJXC80A Differential Pressure
- M Capsule: 2–100 kPa
- H Capsule: 10–500 kPa
- V Capsule, Flush: 0.28–14 MPa
- V Capsule, Extended: 0.28–7 MPa
EJAC80E Differential Pressure
- M Capsule: 2.5–100 kPa
- H Capsule: 25–500 kPa
- V Capsule, Flush: 0.28–14 MPa
- V Capsule, Extended: 0.28–7 MPa
Gauge Pressure Measurement Span
EJXC80A Gauge Pressure
- A Capsule: 0.035–3.5 MPa
- B Capsule, Flush: 0.16–16 MPa
- B Capsule, Extended: 0.16–7 MPa
EJAC80E Gauge Pressure
- A Capsule: 0.06–3.5 MPa
- B Capsule, Flush: 0.46–16 MPa
- B Capsule, Extended: 0.46–7 MPa
Process Connection Options
- Flush flanged seal: 1½ in, 2 in, 3 in
- Extended flanged seal: 3 in, 4 in
- Inner diaphragm seal, adapter connection: ½ in, ¾ in, 1 in
- Inner diaphragm seal, flange connection: ½ in, ¾ in, 1 in
Typical Applications
- Tank level measurement
- High-temperature fluid measurement
- Low-temperature process measurement
- Corrosive chemical measurement
- High-viscosity fluid measurement
- Toxic media measurement
- Media containing suspended solids
- Clogging-prone process lines
- Differential pressure measurement
- Gauge pressure measurement
- Flow measurement
- Density measurement
- Chemical processing
- Petrochemical plants
- Oil and gas facilities
- Refining
- Process vessels
- Storage tanks
- High-temperature process equipment
