Flange-mounted pressure transmitters for high pressure, high temperature, high viscosity and special hygiene requirements refer to pressure transmitters that are connected and sealed through a pair of matching flanges (one on the transmitter and the other on the process pipeline/equipment) using bolts, nuts and gaskets.

Based on the structural relationship between the flange and the diaphragm, they can be divided into two major categories:

1. Flat Flange Type

   Structure: The measuring diaphragm is basically flush with or slightly recessed from the flange end face.

   Advantages: There is no cavity between the flange surface and the diaphragm, and there is no dead zone for the medium. It is particularly suitable for viscous, crystallizable, particulate-containing or easily solidifying media (such as slurry, asphalt, polymers, slurries).

   Applications: It is mainly used in harsh medium pressure measurement in industries such as chemical engineering, petrochemicals, food, and papermaking.

2. Insertion Flange Type

   Structure: The measuring diaphragm is inserted into the pipe or equipment through an extended neck to measure the pressure at a specific depth (such as the bottom of a container, the center of a pipe), or for high-temperature media (to keep the diaphragm away from the high-temperature flange).

   Advantages: It can measure the pressure at a specific position; for high-temperature media, the extended neck can dissipate heat and protect the transmitter.

   Applications: Liquid level/pressure measurement in reaction vessels and large storage tanks, high-temperature steam measurement.

3. Remote Flange Type (Split Type)

   Structure: This is a typical installation method for split-type transmitters. The flange is an independent "remote flange" or "capillary flange", with an isolation diaphragm and filling liquid system inside, connected to the transmitter body through a capillary.

   Advantages: It completely isolates the transmitter body from the process medium. It is suitable for ultra-high temperature, strong corrosion, high viscosity or frequently cleaned environments.

   Applications: Boiler steam, strong acids and bases, food and pharmaceutical aseptic processes, high-temperature reaction processes in reaction vessels.

Flange installation is the standard solution for harsh working conditions and high-standard requirements.

• Chemical and petrochemical processes: Reactor pressure, polymer fluid, catalyst slurry, high-temperature oil.
• Power industry: Main steam/reheat steam pressure of boilers (high pressure, high temperature), feed water pressure.
• Oil and gas industry: Wellhead pressure, oil/gas pipeline pressure (high pressure), separator pressure.
• Food : Tanks and pipelines requiring CIP (cleaning in place) / SIP (sterilization in place), flat flanges ensure no hygiene dead corners.
• Water treatment and slurry: Sewage pump outlet pressure, pulp concentration, slurry pipeline pressure.
• Large tank liquid level measurement: Connected to the tank side wall or bottom through flanges.

Flange-mounted pressure transmitters are fundamental solutions for addressing the most demanding industrial measurement challenges such as high pressure, high temperature, high viscosity, and special hygiene requirements. Through standardized, high-strength flange interfaces, they ensure measurement reliability, long-term sealing safety, and maintenance feasibility even under the harshest conditions.