Nexisense Transmitter Flange Connection Explained: Reliable Installation Ensures Stable Industrial Processes

In industrial production sites such as petroleum and chemical processing plants, the connection method between process pipelines and instruments directly affects system reliability and safety. Flange connections, as one of the most common connection forms, are widely adopted due to their unique advantages. Nexisense transmitter series support flange interface designs and are suitable for high-pressure, high-temperature, or corrosive media applications. This article systematically discusses the principles, characteristics, and practical considerations of flange connections, from basic definitions to real-world applications.

Definition and Function of Transmitter Flange Connections

A flange connection is a detachable joint form in which pipelines, fittings, or transmitters are fixed to flange plates. Two flange plates are fastened together with gaskets and bolts to achieve a sealed connection. It is mainly used to connect transmitters—such as pressure, differential pressure, and level transmitters—to process pipelines or vessels.

Nexisense transmitters using flange connections can withstand high pressure, ensure that the process medium does not leak, and support online maintenance without interrupting production.

Working Principle Analysis

The principle of flange connections is based on mechanical sealing. Two flange plates face each other with a gasket placed in between. Bolts are tightened evenly to generate preload force, compressing the gasket to fill microscopic gaps and form a sealing surface. The higher the internal pressure, the more reliable the seal becomes due to the self-tightening effect.

Key considerations include pressure rating as the primary factor, followed by temperature, medium corrosiveness, and toxicity. Nexisense transmitter flange designs comply with ANSI, DIN, or GB standards to ensure compatibility and safety.

Internal Structure Overview

The structure of Nexisense flanged transmitters includes a flange plate, isolation diaphragm, sensing element, and signal processing module. The flange plate is typically made of 316L stainless steel and integrates vent valves and connectors. The diaphragm comes into direct contact with the process medium, preventing corrosive substances from penetrating the sensing element.

The difference between single and double flange designs lies in the pressure connection method. A single flange transmitter has a direct flange connection on the high-pressure side and an impulse line on the low-pressure side. A double flange transmitter uses flanges on both high and low-pressure sides and is often equipped with capillary tubes filled with silicone oil for remote pressure transmission. This structure provides reliable sealing and flexible system expansion.

Key Advantages

Flange connections offer high reliability, the ability to withstand pressure shocks, and excellent sealing performance. They are easy to install and disassemble, allowing for online inspection and maintenance while reducing downtime.

Compared with threaded connections, flange connections are more suitable for large-diameter pipelines and high-pressure applications. They also allow easier alignment, reducing installation errors. Based on these advantages, Nexisense products further enhance adaptability by offering corrosion-resistant materials and standardized interfaces.

Comparison of Single and Double Flange Characteristics

Single flange: The high-pressure side is directly connected via a flange, while the low-pressure side uses an impulse line. Advantages include high measurement accuracy, while disadvantages include the need to ensure impulse line sealing and perform range migration.

Double flange: Both high and low-pressure sides use flange connections and are often equipped with flexible capillary tubes. Advantages include easy installation, no need for range migration, and simplified calibration, making them ideal for level or differential pressure measurements.

Application Scenario Analysis

Flange connections are commonly used in high-pressure environments such as petroleum refining pipelines, chemical reactors, and storage tank level monitoring. Double flange level transmitters are suitable for sealed vessels, eliminating the need for direct impulse lines, while single flange transmitters are often used in open systems or applications requiring higher accuracy.

In these environments, Nexisense transmitters provide stable signal output and support remote control and safety interlock systems.

Measurement Methods and Installation Steps

Before installation, confirm that the flange rating matches the process pressure requirements. Installation steps include cleaning the flange faces, placing the gasket, aligning the flange plates, and tightening the bolts in a cross pattern with staged torque.

For single flange transmitters, the low-pressure impulse line must be properly sealed and range migration performed. For double flange transmitters, simply connect the capillary tubes. During operation, ensure there is no leakage and that the signal output is correctly connected to the control system.

Maintenance and Care Guidelines

Regularly check bolt tightness to prevent loosening and leakage. Clean flange surfaces to avoid corrosion buildup, and replace aged gaskets promptly.

Maintenance also includes moisture and corrosion protection, as well as safeguarding flange surfaces during storage. Annual verification of sealing performance is recommended to ensure long-term reliability.

Typical Technical Parameters

Typical parameters of Nexisense flanged transmitters include flange standards ranging from PN10 to PN420, materials such as 316L stainless steel or Hastelloy, temperature ranges from -40°C to 150°C (extended with capillaries), accuracy of ±0.075% FS, and output signals of 4–20 mA with HART protocol. Protection rating is IP67, with optional explosion-proof configurations.

Frequently Asked Questions

How to choose between single and double flange transmitters?
Choose single flange for higher accuracy requirements, and double flange for easier installation.

What should be done if flange leakage occurs?
Check bolt torque and gasket integrity, then retighten evenly.

Are they suitable for high-temperature media?
Yes, by using capillary tubes or thermal insulation, high-temperature measurement is achievable.

Is bolt tightening sequence important?
Yes, bolts should be tightened evenly in a cross pattern to avoid uneven load and deformation.

Can flanges with mismatched pressure ratings be used?
No, flange pressure ratings must match to ensure safety.

Conclusion

With high reliability, easy disassembly, and strong adaptability, flange connections have become the preferred installation method for transmitters. Through refined structural design and flexible single and double flange options, Nexisense provides efficient solutions across industries. From petrochemical processes to general process control, standardized flange connections directly enhance system stability and maintenance efficiency. In today’s increasingly stringent industrial safety environment, mastering flange connection details will bring long-term reliability and optimized operational performance to your equipment.