Name: Deublin 355 Series Rotary Union Replacement – OEM Equivalent
SKU: 4621
Availability: InStock

Description

If your existing Deublin 355 Series rotary union is leaking, worn, difficult to source, or becoming expensive to replace, DANN Hydraulic provides compatible rotary union alternatives manufactured according to the required interface and operating conditions. We specialize in replacement rotary unions for imported industrial brands and support customers who need an alternative to Deublin 355 Series rotary union replacement, such as 355-021-002 and related configurations.

Unlike a generic air rotary union, a correct 355 Series replacement must match several important parameters:

– rotor connection
– housing connection
– installation dimensions
– operating medium
– pressure
– temperature
– rotational requirements
– sealing configuration

For this reason, we do not recommend selecting a rotary union based only on appearance or thread size.

Customers can send us the original model number, dimensional drawing, product photos, or a physical sample. Our engineering team will review the application before recommending or manufacturing a replacement.

Our goal is to provide a practical replacement solution for industrial maintenance teams, equipment manufacturers, and distributors who want stable supply, flexible manufacturing quantities, and direct technical communication with a rotary union manufacturer in China.

Key Features of Deublin 355 Series Rotary Union Replacement

1. Stable Mechanical Seal Performance

The rotary union adopts a precision sealing structure designed to maintain reliable fluid transfer during continuous rotation.

Benefits:

Reduced risk of leakage
Stable sealing under rotating conditions
Extended operating life
Improved machine uptime

The optimized sealing design makes it suitable for applications requiring consistent performance in CNC machining and industrial automation equipment.

2. Compact Single Passage Design

The single passage rotary union design provides a simple and efficient flow path for fluid transfer.

Advantages:

Compact structure
Easy installation
Reduced installation space requirements
Suitable for equipment with limited mounting space

This design is commonly used in machine tools, rotary tables, spindles, and industrial rotating assemblies.

3. Precision Machined Components

Each component is manufactured with precision machining processes to ensure dimensional accuracy and reliable operation.

Manufacturing advantages:

Accurate thread machining
Smooth rotating performance
Consistent assembly quality
Reliable compatibility with existing equipment

Our engineering team focuses on maintaining critical dimensions to provide a dependable alternative to original rotary union models.

4. Durable Metal Housing Construction

The rotary union features a robust metal housing designed for industrial environments.

Features include:

High mechanical strength
Corrosion resistance
Good heat dissipation capability
Long-term operational reliability

The durable construction allows the unit to perform effectively in continuous production environments.

5. OEM Replacement Compatibility

We specialize in manufacturing replacement rotary unions for international brands, including Deublin series products.

Our replacement service includes:

Equivalent installation dimensions
Custom thread options
Customized sealing solutions
Small batch and bulk production support

Customers can replace worn rotary unions without modifying existing equipment structures.

Deublin 355 Series rotary union replacement

The Deublin 355 Series includes several rotor connection configurations. Before manufacturing a replacement, we confirm the exact original model and installation dimensions.

Deublin Reference Model	Rotor Connection	Replacement Support
355-021-002	1"-11.5 NPT RH	Available for compatibility evaluation
355-021-016	1-1/2"-12 UNF RH	Available for compatibility evaluation
355-021-017	1-1/2"-12 UNF LH	Available for compatibility evaluation
355-021-019	1-1/2"-12 UNF RH	Available for compatibility evaluation
355-021-222	G1 RH	Available for compatibility evaluation

Different 355 Series models may have different rotor threads, overall dimensions, and installation requirements.

Please do not select a replacement based only on the series number.

For accurate replacement selection, send us:

Original model number
Photo of the existing rotary union
Rotor connection
Housing connection
Operating medium
Pressure
Temperature
Rotational speed

Our engineers can compare the required interface before production.

Typical Applications for Deublin 355 Series Replacement Rotary Unions

The Deublin 355 Series is primarily used where compressed air, hydraulic oil, or vacuum must be transferred from a stationary supply line into rotating equipment.

Our compatible 355 Series rotary union replacements can be evaluated for industrial applications including:

Pneumatic Rotating Equipment

Compressed air rotary unions are commonly required when pneumatic pressure must pass into a rotating shaft, drum, or machine assembly.

Typical requirements include:

– continuous air transfer during rotation
– stable sealing performance
– low rotating torque
– reliable operation during repeated machine cycles

Hydraulic Rotating Equipment

For hydraulic applications, a rotary union allows hydraulic oil to pass between stationary piping and rotating machinery.

When replacing an existing Deublin 355 Series unit, pressure, oil type, temperature, rotational speed, and connection dimensions should all be verified before production.

Vacuum Systems

Certain Deublin 355 Series configurations are designed for vacuum service.

A compatible replacement must maintain appropriate sealing performance while also matching the original installation dimensions and connection configuration.

Industrial Rotating Machinery

The 355 Series design may be found in rotating industrial equipment where a single fluid passage is required between stationary and rotating components.

Instead of selecting a replacement only by external appearance, we recommend checking:

– original Deublin model number
– rotor thread
– housing connection
– working medium
– operating pressure
– temperature
– rotational speed
– installation dimensions

Send us the existing model number or a photo of the nameplate, and our engineering team can help identify the appropriate replacement configuration.

Why Does a Deublin 355 Series Rotary Union Start Leaking?

A rotary union that has operated reliably for years may eventually develop air leakage, hydraulic oil leakage, abnormal noise, or excessive rotational resistance.

The problem does not always mean that the entire machine has failed.

Several conditions should be checked before selecting a replacement.

1. Mechanical Seal Wear

The sealing faces inside a rotary union operate continuously while the machine rotates.

Long operating hours, contamination, excessive temperature, or unsuitable operating conditions can gradually damage the sealing surfaces.

Typical symptoms include:

– visible leakage
– pressure loss
– unstable pneumatic performance
– oil around the rotary union housing

When replacing the unit, the operating medium and actual working conditions should be reviewed rather than simply installing a visually similar rotary joint.

2. Bearing Wear or Shaft Misalignment

Abnormal vibration or shaft misalignment can increase loading on the rotary union.

Possible symptoms include:

– unusual noise
– unstable rotation
– excessive heat
– repeated seal failure

If a new rotary union fails shortly after installation, the machine alignment and hose installation should also be inspected.

3. Contaminated Air or Hydraulic Oil

Particles and contamination can damage precision sealing surfaces.

For hydraulic systems, filtration condition and oil cleanliness should be checked.

For pneumatic systems, air quality and lubrication requirements should be reviewed according to the selected rotary union design.

4. Incorrect Connection or Hose Loading

A rotary union housing should not be subjected to unnecessary torque from rigid piping or incorrectly installed hoses.

Excessive side loading can shorten seal and bearing life.

Before installing a replacement, confirm that the connection arrangement allows the rotary union to operate without unwanted external loading.

5. Wrong Replacement Model

Different Deublin 355 Series models may use different rotor connections and dimensions.

For example, 355 Series variants include NPT, UNF, and G-thread configurations.

Installing a replacement based only on the series name can result in incorrect fit or operating conditions.

Always identify the complete model number before ordering.

Why Source a Deublin 355 Series Replacement From DANN Hydraulic?

DANN Hydraulic / Tianjin Keypower Hydraulic focuses on industrial rotary unions and compatible replacement solutions for imported rotary joint models.

We are not simply matching products by catalogue appearance.

For replacement projects, our manufacturing and engineering process can include:

Engineering Compatibility Review

Before production, we review the original model number, thread configuration, operating medium, pressure, temperature, and installation requirements.

Where necessary, customers can provide:

– original drawings
– existing product photos
– nameplate information
– dimensional measurements
– physical samples

CNC Manufacturing

Critical rotary union components are produced using precision machining processes.

Special attention is given to:

– rotor dimensions
– threaded connections
– sealing interfaces
– bearing locations
– concentricity
– assembly fit

Seal Selection

Seal materials and sealing configurations are selected according to the working medium and operating conditions.

The requirements of compressed air, hydraulic oil, and vacuum applications are not identical, so the application must be confirmed before production.

Inspection Before Shipment

Depending on the product configuration, inspection can include:

– dimensional inspection
– thread inspection
– assembly inspection
– air leakage testing
– pressure testing
– rotational inspection

Replacement and Custom Manufacturing Support

In addition to standard replacement configurations, we can evaluate customized rotary unions when the original model has been discontinued or when an existing machine requires a modified connection.

Our customers include industrial maintenance companies, equipment manufacturers, distributors, and end users looking for an alternative source for imported rotary unions.

Reference Specifications for Deublin 355-021-002 Compatibility

The following specifications are provided as reference information when evaluating a replacement for Deublin 355-021-002.

Original Reference Model: 355-021-002

Rotor Connection:
1″-11.5 NPT RH

Supply Connection:
1″-11.5 NPT

Media:
Air / Hydraulic Oil / Vacuum

Air Reference:
Maximum Pressure: 10 bar
Temperature: 121°C
Flow: 16,990 L/min

Hydraulic Oil Reference:
Maximum Pressure: 69 bar
Temperature: 121°C
Flow: 107.7 L/min

Vacuum Reference:
Maximum Pressure: -0.95 bar
Maximum Temperature: 121°C

Important:

We use these values as reference specifications for the corresponding original model during compatibility evaluation.

Our engineering team confirms the final performance specifications of each replacement rotary union based on the selected configuration, sealing materials, and actual operating conditions.

Please contact our engineering team before replacing an existing rotary union.

FAQ About Deublin 355 Series Rotary Union Replacement

Can you replace a Deublin 355-021-002 rotary union?

Yes. We can evaluate a compatible replacement for Deublin 355-021-002 based on its connection dimensions and actual operating conditions.

Please provide the complete model number and confirm whether the application uses compressed air, hydraulic oil, or vacuum.

What connections are used on Deublin 355 Series rotary unions?

Connection specifications depend on the exact model.

For example, the 355 Series includes configurations using 1″-11.5 NPT, 1-1/2″-12 UNF, and G1 rotor connections.

Always confirm the complete model number before ordering.

Can I replace a Deublin 355 Series rotary union with a Chinese alternative?

A compatible replacement can be considered when the installation dimensions, connection threads, operating medium, and working conditions are correctly matched.

The replacement should not be selected only by external appearance.

What information do you need for a quotation?

Please send:

– Deublin model number
– product photos
– rotor thread
– housing connection
– operating medium
– pressure
– temperature
– rotational speed
– required quantity

If the original model number cannot be identified, dimensional information or a physical sample may also be useful.

My Deublin rotary union is leaking. Do I need to replace it?

Not always.

Leakage may be related to mechanical seal wear, contamination, bearing wear, installation problems, or operating conditions.

However, if the existing rotary union has reached the end of its service life or replacement parts are difficult to obtain, installing a compatible new rotary union may be a practical option.

Can you manufacture according to my existing sample?

Yes. For suitable replacement projects, we can evaluate manufacturing from an existing sample or dimensional information.

The sample should be inspected carefully because a heavily worn component may no longer represent its original dimensions.

Do you support small quantities?

Yes. Small-batch replacement requirements can be evaluated for maintenance companies, equipment owners, and distributors.

Are you an official Deublin distributor?

No.

DANN Hydraulic is an independent rotary union manufacturer providing compatible replacement products.

Deublin is the trademark of its respective owner. References to Deublin model numbers are used only to identify compatibility requirements.

Deublin 355 Series Rotary Union Replacement – OEM Equivalent

Description