Description
1. Introduction to In-line Diaphragm Seal MT-S300FD
The In-line diaphragm seal MT-S300FD is a specially designed pressure isolation component used to ensure accurate pressure measurement in pipelines carrying pure, aggressive, or highly sensitive process media. Unlike conventional diaphragm seals mounted at the side or bottom of a process line, the MT-S300FD is installed directly between two pipeline flanges, positioning the diaphragm directly in the flow path. This makes the seal ideal for hygienic, high-purity, and corrosive media applications where cleanliness, consistency, and contamination prevention are critical.
The completely round geometry without edges or corners prevents material stagnation and ensures that no residue accumulates on the diaphragm surface. As a result, this in-line seal maintains optimal hygienic conditions and measurement accuracy over long operational cycles, even in challenging environments.
Engineered for chemical and petrochemical industries, this diaphragm seal can also be used in biotechnology, pharmaceutical, and food processing systems where strict sanitary standards apply.
2. Key Application Features
Completely Rounded Construction
The In-line diaphragm seal MT-S300FD features a fully rounded body and diaphragm housing, eliminating sharp edges where particles could accumulate. This ensures continuous flow, prevents contamination, and supports clean-in-place (CIP) and sterilize-in-place (SIP) procedures.
Direct Installation Between Two Flanges
The seal is designed for direct flange-to-flange installation without requiring additional fittings. This reduces installation time, minimizes leak points, and improves the overall durability of the system.
Wide Selection of Special Materials
The MT-S300FD can be manufactured using special alloys and corrosion-resistant stainless steels such as AISI L316, ensuring compatibility with aggressive chemicals, high-temperature media, and demanding hygienic conditions.
Permanent In-Pipeline Installation
Its compact and robust design allows it to be installed permanently in the process pipeline. This ensures continuous monitoring and reduces the need for frequent maintenance shutdowns.
Optimized for Pure and Aggressive Media
The diaphragm seal is ideal for pure chemicals, ultra-clean fluids, pharmaceutical-grade inputs, and high-corrosion process streams, ensuring that no metallic or elastomer contamination occurs.
3. Industrial Applications
The In-line diaphragm seal MT-S300FD is specifically used in pipelines where direct contact between the medium and measuring instrument must be avoided. Its applications include:
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Chemical processing plants handling corrosive solvents and reactive compounds
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Petrochemical refineries, including polymer, resin, and catalyst production systems
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Pharmaceutical manufacturing where sterility and purity must be maintained
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Biotechnology production lines, such as fermentation and nutrient media pipelines
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Food and beverage industries transporting dairy products, ingredients, and syrups
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Water treatment and desalination plants handling high-purity liquids
In each case, the diaphragm seal ensures accurate pressure measurement without compromising media quality or instrument safety.
4. Working Principle and Flow Dynamics
The in-line diaphragm seal works by placing a thin, flexible L316 stainless steel diaphragm directly in the flow path. On the opposite side of the diaphragm is a closed chamber filled with silicone oil used as the pressure transmission medium. When the process fluid exerts pressure against the diaphragm, the force is transferred to the pressure gauge or transmitter with no direct contact between the fluid and the instrument.
Because the diaphragm surface is flush with the flow and has no cavities, the flow remains uniform and laminar. This avoids:
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Pressure drop disturbances
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Sediment accumulation
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Flow turbulence
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Contamination or fouling layers
The result is long-term stable measurement accuracy and minimal need for cleaning or recalibration.
5. Benefits of Using the MT-S300FD Seal
High Hygiene and Cleanability
The absence of corners and recesses ensures that the pipeline remains easy to sanitize using automated CIP/SIP procedures.
Improved Measurement Integrity
The diaphragm seal protects the pressure sensing instrument from corrosive and abrasive media, maintaining long-term measurement accuracy.
Extended Equipment Service Life
By preventing the medium from contacting the internal pressure sensor components, mechanical wear and chemical degradation are minimized.
Safe and Reliable Operation
The high-quality welds and sealing surfaces ensure leak-free operation even in high-pressure and high-temperature environments.
Reduced Maintenance Requirements
Permanent installation and smooth flow surfaces reduce buildup, meaning fewer process stoppages.
6. Standard Technical Specifications (PARAMETERS STANDARD)
| Parameter | Specification |
|---|---|
| Pressure Range Type | 0.6 … 0 to 0 … 400 bar |
| Basic Body Material | AISI L316 Stainless Steel |
| Diaphragm Material | AISI L316 Stainless Steel |
| Instrument Connection | Pressure gauge or transmitter welded directly, or threaded adapter |
| Sealing Fluid | Silicone Oil |
| Flange Face Finish | AARH 125 – 250, Raised Face |
| Assembly Type | Direct in-line mounting between two flanges |
This configuration ensures compatibility with most global industrial pipeline flange standards.
7. Installation Options and Compatibility
The In-line diaphragm seal MT-S300FD can be used with:
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Pressure gauges
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Analog or digital pressure transmitters
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Pressure switches
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Remote mount systems via capillaries
Threaded or welded adapters are available to match instrument specifications. The seal may also be configured for vertical or horizontal pipeline orientation, depending on fluid flow direction and system layout.
8. Conclusion
The In-line diaphragm seal MT-S300FD is a highly reliable and hygienic solution for accurate pressure measurement in pipelines carrying pure, aggressive, or contamination-sensitive media. With its rounded geometry, direct flange installation, wide material selection, and robust sealing system, it ensures stable long-term performance in both chemical and petrochemical industries, as well as food, biotech, and pharmaceutical applications.
Its precision engineering and ease of cleaning make it the preferred choice where system purity, safety, and operational continuity are critical.
