Mosmatic DYDI Rotary Union Swivel – M22 x 1.5 Male x G3/8 Male, 7300 PSI Stainless Steel

Part Number: 55.263
Category: Pressure Washer Parts → Swivels & Fittings → Rotary Unions
Type: Mosmatic DYDI Rotary Union Swivel – M22 x 1.5 Male x G3/8" Male Stainless Steel, 7300 PSI

The Mosmatic 55.263 DYDI Rotary Union Swivel is a genuine Mosmatic ultra high-pressure rotary union engineered for demanding high-RPM and high-pressure applications including professional pressure washing, surface cleaners, self-rotating cleaning equipment, parts washers, automatic wash systems, and industrial fluid transfer. Designed with an M22 x 1.5 Male inlet and G3/8-inch Male (BSPP) outlet, this premium rotary union delivers smooth 360-degree continuous rotation while maintaining unrestricted fluid flow under extreme operating conditions.

Key Features & Benefits

• Genuine Mosmatic OEM rotary union
• Manufacturer Model: 55.263
• DYDI series rotary union
• Ultra high-pressure design
• Ideal for high-RPM applications
• M22 x 1.5 Male inlet
• G3/8" Male (BSPP) outlet
• Smooth 360° continuous rotation
• Complete stainless steel construction
• Premium carbide seal system
• Sealed stainless steel bearing system
• Two radial ball bearings and one thrust ball bearing
• Built-in weep holes indicate seal wear
• Rated for systems up to 7,300 PSI (50 MPa)
• Supports rotational speeds up to 2,000 RPM
• Maximum operating temperature: 250°F
• Compatible with filtered water and compressed air applications

Technical Specifications

Manufacturer: Mosmatic

Manufacturer Model: 55.263

Series: DYDI

Product Type: Rotary Union Swivel

Inlet Connection: M22 × 1.5 Male

Outlet Connection: G3/8" Male (BSPP)

Nominal Width: 1/4"

Maximum Working Pressure: 7,300 PSI (50 MPa)

Maximum Speed: 2,000 RPM

Maximum Temperature: 250°F

Body Material: Stainless Steel

Internal Components: Stainless Steel

Seal Material: Tungsten Carbide

Bearing System:

• 2 Radial Ball Bearings
• 1 Thrust Ball Bearing

Compatible Media:

• Filtered water (10-micron filtration recommended)
• Compressed air (up to 290 PSI)

Recommended Fluid pH Range: 3–12

Swivel Rotation: 360°

Weight: 23 oz

OEM Replacement: Yes

Compatible Applications

Ideal for:

• Professional pressure washers
• High-pressure surface cleaners
• Self-rotating spray bars
• Rotary cleaning equipment
• Parts washers
• Automatic vehicle wash systems
• Industrial cleaning equipment
• Wash booms
• High-speed rotating machinery
• Industrial fluid transfer systems
• High-pressure spray equipment

Always verify thread type, operating pressure, RPM requirements, and equipment compatibility before ordering. G3/8 BSPP threads are not interchangeable with NPT threads without the appropriate adapter.

Function of the Rotary Union

The Mosmatic 55.263 DYDI Rotary Union helps:

• Provide smooth 360° continuous rotation
• Maintain unrestricted high-pressure water flow
• Support ultra-high-pressure systems up to 7,300 PSI
• Operate reliably at speeds up to 2,000 RPM
• Prevent hose twisting and mechanical stress
• Improve reliability in self-rotating cleaning equipment
• Extend the service life of connected hoses and rotating components

Its carbide seal system and sealed stainless steel bearing assembly provide exceptional durability in continuous-duty, high-speed applications.

Common Signs Replacement Is Needed

Replace the rotary union if you notice:

• Water leaking from the swivel body
• Leakage from the weep holes indicating seal wear
• Rough or restricted rotation
• Excessive rotational play
• Damaged or worn threads
• Corrosion or physical damage
• Reduced performance under high pressure or high RPM

Replacing a worn rotary union restores reliable, leak-free operation and helps prevent damage to connected equipment.

Installation & Service Notes

Turn off the pressure washer or equipment and relieve all system pressure before installation.

Verify that the equipment uses an M22 × 1.5 Male connection and a G3/8 BSPP Male connection. BSPP fittings typically seal using an O-ring or bonded seal and should not be installed as standard NPT fittings.

Install the rotary union securely without overtightening and verify smooth rotation before operating the equipment.

Use filtered water (10-micron maximum) for optimal seal life. If used with compressed air, do not exceed 290 PSI.

Important: Never exceed the maximum 7,300 PSI working pressure, 2,000 RPM rotational speed, or 250°F operating temperature. Always verify compatibility with your equipment and thread types before installation.

Maintenance Recommendations

• Inspect the rotary union regularly for smooth rotation and leaks.
• Monitor the built-in weep holes for early signs of seal wear.
• Always use filtered water (10-micron filtration recommended).
• Keep the swivel clean and free of dirt, debris, and mineral buildup.
• Inspect threaded connections during routine maintenance.
• Replace worn seals or damaged components promptly.
• Use only genuine Mosmatic OEM replacement parts to maintain proper fit, maximum reliability, and long service life.