Mosmatic 55.163 DYC Carbide Swivel – 3/8" FPT x G 3/8" M Stainless Steel Rotary Union

Part Number: 55.163
Category: Pressure Washer Parts → Swivels & Fittings
Type: Mosmatic 55.163 DYC Carbide Swivel – 3/8" FPT x G 3/8" Male Stainless Steel Rotary Union

The Mosmatic 55.163 DYC Carbide Swivel is a genuine Mosmatic premium rotary union engineered for demanding pressure washing, surface cleaning, industrial cleaning, vehicle wash systems, wash booms, and other high-pressure fluid transfer applications. Designed with 3/8-inch Female NPT and G 3/8-inch Male (BSPP) threaded connections, this heavy-duty swivel provides smooth 360-degree rotation while preventing hose twisting, reducing stress on plumbing components, and extending equipment service life.

Key Features & Benefits

• Genuine Mosmatic OEM rotary union swivel
• Manufacturer Model: 55.163
• DYC series carbide swivel
• 3/8" Female NPT inlet
• G 3/8" Male (BSPP) outlet
• Smooth 360° rotary union operation
• Premium stainless steel construction
• Tungsten carbide sealing system
• Excellent corrosion resistance
• Designed for continuous-duty applications
• Helps prevent hose twisting and kinking
• Reduces stress on hoses and plumbing components
• Long service life with minimal maintenance

Technical Specifications

Manufacturer: Mosmatic

Manufacturer Model: 55.163

Series: DYC

Product Type: Carbide Rotary Union Swivel

Inlet Connection: 3/8" Female NPT

Outlet Connection: G 3/8" Male (BSPP)

Body Material: Stainless Steel

Seal Material: Tungsten Carbide

Swivel Rotation: 360°

OEM Replacement: Yes

Compatible Applications

Suitable for use with:

• Commercial pressure washers
• Industrial pressure washing systems
• Surface cleaners
• Vehicle wash systems
• Wash booms
• Self-service car wash equipment
• High-pressure hose reels
• Industrial cleaning equipment
• Rotary cleaning systems
• High-pressure fluid transfer applications

Always verify thread type, connection size, operating pressure, and equipment compatibility before ordering. G 3/8 is a BSPP (British Standard Parallel Pipe) thread and is not interchangeable with 3/8" NPT threads without the proper adapter.

Function of the Rotary Union Swivel

The Mosmatic 55.163 DYC Carbide Swivel helps:

• Provide smooth 360° rotation under pressure
• Prevent hose twisting and kinking
• Reduce stress on plumbing connections
• Maintain unrestricted fluid flow
• Extend the service life of hoses and rotating equipment
• Deliver long-lasting performance with its carbide sealing system

Its precision-engineered tungsten carbide seal offers exceptional wear resistance, making it ideal for continuous-duty applications where reliability and longevity are essential.

Common Signs Replacement Is Needed

Replace the swivel if you notice:

• Water leaking around the rotary union
• Restricted or rough swivel movement
• Excessive hose twisting
• Worn or damaged threads
• Corrosion or physical damage
• Reduced swivel performance under pressure

Replacing a worn rotary union restores smooth operation and helps protect connected hoses and equipment.

Installation & Service Notes

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

Apply an appropriate thread sealant to the 3/8" Female NPT connection where required. Do not apply thread sealant to the G 3/8 (BSPP) connection unless specified, as BSPP fittings typically seal with a gasket or O-ring rather than thread interference.

Tighten all fittings securely without overtightening.

Verify the swivel rotates freely and inspect the system for leaks before placing equipment into service.

Important: Always verify thread compatibility before installation. G 3/8 BSPP threads require compatible BSPP fittings and are not directly compatible with NPT threads.

Maintenance Recommendations

• Inspect the swivel regularly for leaks and smooth rotation.
• Keep the swivel clean and free of dirt, debris, and mineral buildup.
• Inspect sealing surfaces during routine maintenance.
• Replace worn seals or damaged components promptly.
• Inspect hoses for twisting or abnormal wear during operation.
• Use only genuine OEM Mosmatic replacement parts to maintain proper fit, reliable performance, and long-term service life.