Water rotary union DN250-FF

for gasfor compressed airfor oil

Product Overview
Maximize efficiency and reliability in heavy-duty rotating machinery with the DN250 Flange-to-Flange Rotary Joint. Engineered for demanding industrial environments, this large-bore union provides leak-free transfer of water, oil, or gas from a stationary pipe into a slowly rotating drum, roller, or cylinder and is built to withstand massive axial loads for continuous-process applications.

Short Description
DN250/DN300 FF Series High-Capacity Rotary Union
1.6 MPa | 3,200 kg Load | Water/Oil/Gas

Key Features & Benefits

• Superior Load-Bearing Design: axial load capacity of 3,200 kg with robust bearings and a rigid housing to support connected piping and equipment for stable operation and long service life under heavy loads.
• Versatile Media Compatibility: sealed and constructed from high-grade materials to handle Water, Lubricating Oil, Hydraulic Oil, Compressed Air, and inert gases.
• Robust Performance Parameters: operates up to 1.6 MPa and across a temperature range from -40°C to +120°C for diverse climates and conditions.
• Precision for Low-Speed Applications: optimized for smooth, leak-free operation at low rotational speeds (0–30 RPM), suitable for large dryers, calenders, mixers and other slow-turning heavy equipment.
• Flange-to-Flange Connection: standardized, bolted flanges for secure connection, ease of installation and maintenance, and resistance to piping stress.
• Durable Construction: precision-engineered components and high-quality seals to minimize wear, reduce maintenance and prevent fluid leaks.

Ideal Applications

• Paper industry: dryer cylinders, calender rolls.
• Steel & metal processing: cooling rolls in continuous casting, roll neck cooling in rolling mills.
• Rubber & plastics: internal mixers (Banbury), calenders, mill rolls.
• Printing & textile: large drying drums, printing cylinders.
• General heavy machinery: rotating equipment requiring high-flow fluid transfer with significant axial load.

Table 1: Core Performance & Physical Data
Parameter: Model — Specification — Remarks
Model: DN250-FF Series — Flange-to-Flange Connection Type
Nominal Diameter (DN): 250 mm — Standard pipe/port size
Connection Type: Flanged (FF) — Bolted flange connection per standard
Max. Working Pressure: 1.6 MPa (~232 PSI) —
Speed Range: 0 – 30 r/min — Recommended for optimal seal life
Temperature Range: -40°C to +120°C —
Axial Load Capacity: 3,200 kg — Maximum recommended thrust load
Media Compatibility: Water, Lubricating Oil, Hydraulic Oil, Compressed Air, Inert Gases — Specify media for seal recommendation

Table 2: Standard Materials & Media Guide
Component: Standard Material — Notes
Main Body / Housing: High-Strength Carbon Steel or Ductile Iron — Standard finish: anti-rust paint; stainless steel optional
Rotating Shaft: Precision Hardened Carbon Steel — Chrome-plated sealing surface available for wear resistance
Seals: NBR, FKM (Viton), or EPDM — Material selected based on specific medium and temperature
Bearings: Heavy-Duty Tapered Roller Bearings — For high radial & axial load capacity
Gaskets: Rubber-Embedded Metal Gasket — For flange connections

Technical Characteristics / Specifications

• Model series: DN250-FF Series
• Nominal diameter (DN): 250 mm
• Connection type: Flanged (FF), flange-to-flange
• Max. working pressure: 1.6 MPa (~232 PSI)
• Recommended speed range: 0–30 r/min
• Temperature range: -40°C to +120°C
• Axial (thrust) load capacity: 3,200 kg
• Media compatibility: water, lubricating oil, hydraulic oil, compressed air, inert gases
• Main body/housing materials: high-strength carbon steel or ductile iron (stainless optional)
• Rotating shaft: precision hardened carbon steel (chrome-plated option)
• Seals: NBR, FKM (Viton), EPDM (selected per medium/temperature)
• Bearings: heavy-duty tapered roller bearings
• Gaskets: rubber-embedded metal gasket for flange connections