Why Choose OMSS DIN Union
- Cooperated with 20 nations’ clients, with exceptional experience in fluid equipment components.
- Using Mazak CNC equipment from Japan, high-tech machinery for precision.
- Strict quality inspection before shipping, measured by spectrometers.
- Offering customised service, support OEM marking
- Stable in delivering and shipment, prevent delaying your production.
- Provide Surface roughness measurement reports of DIN Union before shipping.
OMSS: Your Reliable DIN Union Supplier
OMSS is an expert in producing OEM stainless steel equipment components. With 15 years of industry experience and high-tech machinery, OMSS supplies phenomenal stainless steel fluid equipment.
The OMSS stainless steel DIN union is used across a wide range of industries that require fluid equipment. It is exceptional in rust and corrosion resistance. You can easily install and remove it for maintenance and cleaning, and it matches the requirements for high hygienic standards. If you are selecting DIN unions, contact us and get optimal DIN unions customised for your factory.
Our Products
Secured fastening with precise sizes, quick assembling design, and durable material. High compatibility for DIN standard accessories, fit the design of modular piping systems.
More compact design, shorter than standard male connectors, ideal for space-constrained pipe layouts. Excellent vibration resistance maintains stable connections in high-vibration environments.
Stable welding connections for higher structural integrity. Easily cleaned and maintained, with smooth weld seams and compact designs, facilitate CIP processes.
Hygienic and food standards. Smooth surface and interior cavity for liquid flow and cleaning. Stronger welded joints reduce the risk of leakage.
Designed for the DIN 11851 standard and widely applied. Less hard-to-reach areas, smooth transition in welded joints, and minimising the risk of bacterial buildup.
Chain-link structure avoids nut loss, facilitates on-site maintenance to prevent downtime caused by missing parts, and reduces the risks of worker misinstallation or misplacement.
Larger sealing surface with extended design increases the sealing surface area, enhancing sealing performance. Extended connection sections promote mechanical load-bearing capacity.
High deformation tolerance by enhancing stability under partial dynamic or temperature-varying conditions, and is suitable for CIP/SIP sanitation processes.
Features of OMSS DIN Union
OMSS DIN union has reliable sealing performance. The construction of a precisely manufactured sealing surface and a sealing gasket ensures the sealing surface alignment consistency and even compression.
316L stainless steel provides resistance to acids, alkalis, and solvents. It reduces pitting and surface degradation, ensuring safe fluid transfer even in harsh chemical conditions.
OMSS DIN union resists a wide temperature range. Stainless steel remains robust in a wide range of temperatures, and the gasket is also thermally resistant.
OMSS DIN union maintains a stable connection under the vibration of pumps and compressors over time. The clamping structure reduces loosening and fosters operational safety.
OMSS DIN union has excellent high-pressure resistance. The stainless steel and thread clamping structure ensures mechanical strength, which maintains secure connections with evenly distributed stress.
The internal bore of the OMSS DIN union is produced precisely and finely polished. It ensures smooth flow and reduces turbulence, pressure drop, and energy loss.
OMSS DIN unions are manufactured according to the DIN standard. This allows the compatibility between components from different suppliers and simplifies procurement, system expansion, and spare part replacement.
Stainless steel, as the main material of the OMSS DIN union, is completely recyclable. It is clean manufactured, has no water pollution, and reduces the burden of environment.
Easy Installation and Removal
OMSS DIN union is easy to install and remove without welding. It can be assembled with tools, including spanners, wrenches, and lubricant. DIN Union can be removed quickly without cutting the pipe or breaking the adjacent components. This feature enables you to clean DIN Unions thoroughly and frequently, reducing downtime and promoting operational efficiency.
The DIN standard ensures compatibility between components from different suppliers, which simplifies system upgrades and part replacements.
High Hygienic Standard
OMSS DIN union meets high hygienic standards and is ideal for sanitary process systems. It’s made of high-quality 304, 304L, or 316L stainless steel. Stainless steel has exceptional corrosion resistance, which prevents contamination. And the interior surface is finely polished to eliminate the roughness, which reduces the risk of bacterial growth and product residue accumulation.
Moreover, the gasket materials meet the food-grade certified requirements and ensure stable sealing performance.
Durable for Long Service Life
OMSS DIN union is made of 304, 304L, and 316L standard stainless steel, which are durable for resistance to rust and corrosion, temperature fluctuations, and high-pressure environments. Stainless steel offers excellent mechanical strength and oxidation resistance, ensuring structural integrity over time.
Additionally, the replaceable gasket design also helps with longevity. When the gasket wears out, you can simply change the gasket instead of the whole union. In this way, you can save on maintenance costs and reduce material waste.
Applications of DIN Union
OMSS DIN unions are applied in the liquid food production system. The reliable connections and sealing performance prevent leakage and contamination on your pipelines.
Food factories require routine CIP (cleaning-in-place) procedures to maintain sanitary conditions. OMSS DIN union is made of stainless steel that is capable to clean with hot water and steam.
In addition, OMSS DIN unions can separate the pipes quickly and adapt modular processing systems. Therefore, your production lines can be reconfigured for different product batches easily.
In the pharmaceutical industry, OMSS DIN unions are used to transport purified water, chemical solutions, and active pharmaceutical ingredients. The stable connection of the unions keeps the pressure and liquid flow consistent.
The pharmaceutical facilities require frequent sterilisation procedures. Stainless steel, as the main body material of the OMSS DIN union, is capable to endure steam cleaning and chemical disinfectants. The smooth interior surface is also anti-bacterial.
In water treatment systems or industry, OMSS DIN unions are used to connect pipelines carrying clean water, filtered water, and treated water. The stainless steel’s corrosion resistance is a crucial ability for the consistent moisture environments.
And OMSS DIN unions secure sealing and prevent leaks by their sealing structure, and promote the efficiency of the water treatment system.
In the oil and gas industry, OMSS DIN unions are used in the secondary fluid pipelines, including cooling water lines, chemical injection systems, and lubrication circuits. The corrosion resistance of 316L stainless steel is ideal for offshore platforms, which are exposed to seawater and salty spray.
And the capacity of quick installation and removal makes OMSS DIN unions easy for you to maintain.
- Certificate of Compliance
Customer Reviews
We purchased sanitary tri clamp fittings and stainless steel ferrules from OMSS for our beverage processing system. The dimensions were accurate, the polishing was clean, and the fittings connected smoothly with our existing pipes without additional adjustment. The consistent quality helped us improve installation efficiency.
EmilyOMSS supported our custom stainless steel fitting project from drawing confirmation to final production. Their engineers provided useful suggestions on material selection and processing details. The finished components matched our requirements well and performed reliably in our food equipment applications.
We have strict requirements for surface finish and hygiene standards in pharmaceutical equipment. OMSS stainless steel fittings showed excellent workmanship, with smooth surfaces and precise machining. Their products helped us meet our equipment assembly requirements and maintain reliable production performance.
316 stainless steel and 316L stainless steel used in OMSS DIN Unions differ in their carbon content. 316 stainless steel has a max carbon content of 0.08%, while 316L stainless steel has a 0.03% max content. Because 316 has more carbon content than 316L, it is more vulnerable to weld decay than 316L. 316L resists corrosion better than 316 stainless steel.
There are several tips for you to maintain the OMSS DIN union.
First, check the sealing gasket regularly. Second, avoid screwing up the DIN unions too tightly. Third, wipe the surface until it is dry after you clean it each time.
And if you ordered 304 stainless steel DIN Unions, avoid exposure to chloride ions, which can be found in seawater and salty spray.
DIN and SMS are both used in pipeline systems. They have different technical specifications, thread profiles, dimensions, and sealing geometries and are not interchangeable.
DIN is based on the German standard and used in Germany and central Europe, and the international markets influenced by Germany, while SMS is based on the Swedish standard and used in northern Europe.
They also differ in sealing structure. The design of the male and liner is different.
Compared to welded connections, DIN unions have more edges in operation and costs.
Welded connections are permanent and need to be operated by specialised workers, while DIN unions can be reconnected and operated easily with your common tools. When the connection is to be reformed, welded joints can only be removed by breaking the pipes, and this requires more time and cost to reform the connections.
There are three common mistakes in installing the DIN unions.
- Selecting improper gaskets: When the material of the gasket does not match the temperatures and process medium, it may lead to swelling, cracking, or leakage.
- Improper alignment: If the male and liner components are not properly aligned before tightening the nut, the pressure will be uneven and damage the gasket, resulting in leakage.
- Mixing incompatible standards: Using different standards of unions can lead to a thread mismatch and sealing failure.
What Is a DIN Union?
A DIN union is a detachable pipe fitting and is used in the fluid handling systems of a wide range of industries, including food, beverage, pharmaceutical, and chemical industries. It matches the German Industry standard, which is known as the DIN Standard.
A DIN Union allows two pipelines to be quickly installed and profoundly sealed without welding. Therefore, you can easily assemble and disassemble it for cleaning and maintenance.
DIN Standard Background
DIN refers to Deutsches Institut für Normung (German Institute for Standardisation in English). DIN Standard is widely used in the food and pharmaceutical industries in Europe.
A DIN Union usually matches these two common standards: DIN 11851 and DIN11864.
Comparison Between DIN 11851 and DIN 11864
| DIN 11851 | DIN 11864 | |
| Application | Food & Dairy | Pharmaceutical & Biotech |
| Hygienic Level | Hygienic | Aseptic |
| Sealing Type | Flat gasket | O-ring / aseptic seal |
| Surface Finish | Ra ≤ 0.8 μm | Ra ≤ 0.6 μm |
| Dead Space | Possible | Minimised/eliminated |
| Cleaning Method | CIP | CIP & SIP |
| Material | 304 / 316L | Mainly 316L |
| Cost | Moderate | Higher |
Structure of DIN Union
DIN unions are a hygienic union compliant with the standard, which is commonly used in Europe. DIN unions consist of four parts: the threaded male part, a conical weld liner, a slotted nut, and a seal.
The seal sets within the recess on the male part, and the colonial liner ensures the union aligns correctly when being tightened. DIN unions are sized to butt weld DN Metric tube sizes.
Threaded Male Part
The male part is one of the core components of a DIN union. The thread outside aligned with the nut’s inside thread and engaged together. Its sealing surface coordinates with the gasket and the liner. The male threaded part is the key sealing interface and performs a mechanical fixing function.
Liner/Welding Ferrule
The liner is permanently fixed by welding to the pipes. It is a transitional structure to stably fix with the pipes and maintain the union’s flexibility. The liner interior surface is usually polished to secure the hygienic condition. As a basic component, the liners play a key role in precision, fluid efficiency, and mechanical strength.
Nut
The nut is a fastening component of the DIN union. The ironside thread coordinates with the outside thread on the male part and transfers the torque into axial clamping force, pressing the gasket and creating a sealing condition.
Nuts are mostly round-shaped and with structure especially designed for tools. The removable design of the nut makes the pipe system easily separated during maintenance and reforming without cutting the pipes.
Gasket/ Seal
The sealing gasket is placed between the male part and the liner. It is the key component to achieve the sealing function. When the nut is screwed tightly, the gasket is evenly compressed and fills the micro gaps on the metal surface, therefore preventing leakage.
The common gasket materials include EPDM, PTFE, NBR and silicone, etc. The specific material depends on the temperature range, pressure rating and chemical compatibility. The gasket should be elastic in vibrative conditions.
Working Principle of DIN Union
The working principle of the DIN union is based on mechanical compression and standardised thread engagement. When you install the union, put the sealing gasket between the sealing surface of the male part and the front face of the liner. Then tighten the thread nut.
When torque is applied to the nut, the thread interaction generates an axial clamping force. This axial force pushes the male component toward the bushing, causing the gasket to compress uniformly between the two sealing surfaces. The compressed gasket fills all the microscopic gaps and forms a tight seal structure that prevents fluid leakage.
The sealing effect depends on the even pressure, proper alignment and matching gasket. The male part is removable when the liner is welded to the pipe. And the design enhances the pipe system with stability and flexibility.
Common Size and Standard of OMSS DIN Union
Size and Standard（DN & OD）
| DN | OD(mm) | Thread | Nut Size(mm) | Length(mm) |
| DN10 | 13 | Rd28x1/6 | 44 | 40 |
| DN15 | 19 | Rd34x1/6 | 50 | 45 |
| DN20 | 23 | Rd44x1/6 | 65 | 50 |
| DN25 | 29 | Rd52x1/6 | 75 | 55 |
| DN32 | 35 | Rd58x1/6 | 85 | 60 |
| DN40 | 41 | Rd65x1/6 | 95 | 65 |
| DN50 | 53 | Rd78x1/6 | 110 | 70 |
| DN65 | 70 | Rd95x1/6 | 130 | 80 |
| DN80 | 85 | Rd110x1/4 | 150 | 90 |
| DN100 | 104 | Rd130x1/4 | 180 | 100 |
| DN125 | 129 | Rd160x1/4 | 210 | 120 |
| DN150 | 154 | Rd190x1/4 | 240 | 140 |
Selection Guide for OMSS DIN Union
Material（304/316L）
304/ 304L Stainless Steel
304 and 304L stainless steel are durable materials for the general food industry and indoor environments. It is capable of being cleaned by the CIP system and has excellent antioxidant capacity.
304 stainless steel contains 18% chromium and 8% nickel approximately. It is easy to machine and performs well in polishing. The cost is relatively lower compared to 316L stainless steel.
316L Stainless Steel
316L stainless steel contains 2–3% molybdenum and has better chloride resistance compared to 304 stainless steel. They have exceptional corrosion resistance and dapts marine and harsh chemical environments. But they have a higher cost than 304 stainless steel.
Gasket Material
| Gasket Material Selection | ||
| Material | Temperature Range | Feature |
| EPDM | -20~120°C | Ordinary Food Standard |
| PTFE | -40~200°C | Strong Chemical Resistance |
| Silicone | -50~180°C | Healthcare Industry |
Surface Finish
OMSS DIN unions go through electrolytic polishing, which ensures the cleaning effect and matches the hygienic standard.
Pressure Rating
The pressure rating depends on the material, size, gasket material, and the applied temperature. And the general range is from PN10 to PN40.
