Main features & Overview


The HWX4 series of Gefran, are pressure transmitters for using in High temperature environment and specifically designed for melt pressure measurement and available to be used in large-scale fixed installations or in large-scale stationary industrial tools rather than laboratory equipments.

The HWX4 series of Gefran are flanged pressure transmitters with HART communication protocol for using in high temperature environment with explosive atmosphere presence.

The main characteristic of this series is the capability to read temperature of the media up to 315°C.

The constructive principle is based on the hydraulic trasmission of the pressure.

The fluid-filled system assures the temperature stability.

The physical measure is transformed in a electrical measure by means of strain-gauge technology.

The SIL2 and PL d approvals make the product suitable for use in the Functional Safety applications, particularly in the process plants for the production of polymers, where

it is an essential requirement.


• Pressure ranges from: 0-17 to 0-1000 bar / 0-250 to 0-15000 psi

• Thick film extensimetric measurement principle

• Accuracy: < ±0.25% FS (H); < ±0.5% FS (M)

• SIL2 and PL d approvals for Functional Safety

• ATEX certification for potentially explosive atmospheres

• Flanged version

• Protection level: IP66 (6-pin connector)

• 1/2-20UNF, M18x1.5 standard threads; other types available on request

• 17-7 PH corrugated diaphragm with GTP+ coating


Gefran product range brochure
Melt pressure sensors
4.0 Gefran product catalog
4.0 plastic application catalogue
Flyer Melt for Polymers
HWX4 Datasheet
HWX4 - HMX4 Safety note


Hart Certifications - Certificate of Registration HCF Verified
GTP+ FDA Certificate
HM_HW_HK Melt HART Certification
EU Conformity declaration_HWX FS over 500bar SIL 2
EU conformity declaration_HWX FS min 500bar SIL 2