Anti Vibration Plug Hose

Quick couplings

The Nitto Kohki Anti Vibration Plug Hose is a rubber plug element with integrated vibration damping, mounted directly on compressed-air tools. The series covers two types: SHA-3-2R and SHA-3-3R, both manufactured from rubber. The component decouples vibrations of the pneumatic tool from the connected hose and reduces the transmission of pulse and impact loads to the coupling connection and the downstream hose assembly.

⚙ Rubber construction - Elastic material absorbs vibration and impact forces between tool and hose coupling

✓ Two variants - SHA-3-2R and SHA-3-3R for different hose diameters or connection geometries

↕ Direct tool mounting - Plug element with quick-coupling-compatible connection, compatible with Nitto Kohki HI Cupla range

⬡ Extended coupling service life - Reduction of fatigue loading on the coupling and hose end through vibration isolation

Type	Material	Function
SHA-3-2R	Rubber	Anti-vibration plug for hose connection type 2
SHA-3-3R	Rubber	Anti-vibration plug for hose connection type 3

The type designation indicates the body size and hose connection type. Both variants are compatible with the standard Nitto Kohki HI Cupla socket range.

Typical applications: Air impact wrenches and screwdrivers with high vibration in assembly, grinders and chisels in metalworking, pneumatic riveting tools in aerospace and automotive manufacturing, and all hose connections to pneumatic tools where pulse loading limits coupling service life.

Technical data from the manufacturer catalogue

Series	ANTI-VIBRATION PLUG HOSE
Max working pressure	1.5 MPa {15 kgf/cm2, 15 bar, 218 PSI}
Valve structure	One-way shut-off
Applicable fluids	Air
Size range	R 1/4 (SHA-3-2R), R 3/8 (SHA-3-3R)
Catalogue page	C01en-b, 66

Operating principle

On disconnection the valve in the socket closes the supply line. The fluid left in the plug escapes.

Connecting sequence of a ball locking quick connect coupling.

Optimizes life and prevents wear of CUPLA by absorbing strong shocks generated by connected vibrating tools.
Prevents hard-to-notice flow reduction caused by CUPLA wear under continuous vibration.
Flexible rubber hose allows free and wide range of tool motion.
Protects CUPLA from shock generated by vibrating tools and impact tools.

All models of the series

SHA-3 - Male thread

Model	Coupling part	Application	T	øMinimum bend radius	øOverall length
SHA-3-2R	plug hose	R 1/4 male thread type	R 1/4	135 mm	320 mm
SHA-3-3R	plug hose	R 3/8 male thread type	R 3/8	135 mm	320 mm

Dimensions in millimetres. Values in brackets apply in the connected condition.

Legend: L = overall length; H = width across flats or outside dimension; D = socket outside diameter; A = hose barb length; C = sleeve dimension; T = thread or barb size; B = bore

Series comparison

Series	Max working pressure	Size range	Valve structure	Applicable fluids
COMPACT ZEROSPILL CUPLA	10 bar	Thread 1/8 inch, 1/4 inch	Two-way shut-off (Spill Reduction)	Air, Water
CUPLA HOSE with FULL BLOW CUPLA	10 bar	Hose size ø5 mm×ø8 mm, ø6.5 mm×ø10 mm, ø8.5 mm×ø12.5 mm	One-way shut-off	Air
FLOW MONITOR	10 bar	Rc 3/8 and Rc 1/2	-	Water
ANTI-VIBRATION PLUG HOSE	15 bar	R 1/4 (SHA-3-2R), R 3/8 (SHA-3-3R)	One-way shut-off	Air
HI CUPLA BL	15 bar	1/4 inch, 3/8 inch, 1/2 inch (thread and hose barb); SN type for urethane hose: for 6.5 x 10 mm, 8 x 12 mm and 8.5 x 12.5 mm hose	One-way shut-off	Air, Water
HI CUPLA Two Way Type	15 bar	Thread 1/4 inch, 3/8 inch, 1/2 inch. Hose barb for dia. 6.5 mm x dia. 10 mm and dia. 8.5 mm x dia. 12.5 mm hose.	One-way shut-off	Air
FLATFACE CUPLA F35	350 bar	Thread 1/4 inch, 3/8 inch, 1/2 inch, 3/4 inch, 1 inch	Two-way shut-off (Spill Reduction)	Hydraulic oil
FLATFACE CUPLA FF	350 bar	3/8 inch, 1/2 inch, 3/4 inch, 1 inch (thread)	Two-way shut-off (Spill Reduction)	Hydraulic oil

Choose the ANTI-VIBRATION PLUG HOSE when a vibrating or percussive air tool runs at up to 1.5 MPa {15 kgf/cm2} and the coupling itself has to be kept away from the shock: it is an intermediate hose carrying a HI CUPLA Plug 30PH, not a coupling mounted directly on the tool. The one-way shut-off sibling series in this group, such as HI CUPLA BL, LOCK CUPLA 200 or ROTARY PLUG, carry the same 1.5 MPa {15 kgf/cm2} rating but connect the tool directly. Where the fluid has to be held on both sides at disconnection, take a two-way shut-off series such as COMPACT ZEROSPILL CUPLA, which is rated 1.0 MPa {10 kgf/cm2}.

Further catalogue data

Note	Value
Inlet (Plug)	HI CUPLA Plug 30PH
Pressure units	1.5 MPa, 15 kgf/cm2, 15 bar, 218 PSI
Air hose	Rubber hose for air
Overall length	320 mm
Minimum bend radius	135 mm
Maximum tightening torque, Nm {kgf cm}	R 1/4: 14 {143}, R 3/8: 22 {224}

Interchangeability and size groups

Interchangeable with sockets of HI CUPLA models 10, 17, 20, 30, 40 and 60. Interchangeable with each models of NUT CUPLA series and HI CUPLA series (except models 400, 600, and 800). Please see page 21 for HI CUPLA Series Interchangeability.

Safety and application notes

Before use, please be sure to read the Safety Guide described at the end of this book and the Instruction Sheet that comes with the products.

All technical data on this page is taken from the Nitto Kohki general catalogue Quick Connect Couplings C01en-b, page 66. The complete catalogue is available for download on this page.

What are anti-vibration plug hoses and what industrial applications require them?

Anti-vibration plug hoses are specialized pneumatic connectors designed to reduce mechanical vibrations and acoustic noise in compressed air and hydraulic systems through integrated damping elements. These quick-connect couplings are essential in manufacturing environments where precision machinery, automated assembly lines, and CNC equipment require stable fluid power transmission without vibration-induced interference. The Nitto Kohki SHA-3 series anti-vibration plug hoses are particularly critical in semiconductor fabrication, pharmaceutical production, and automotive assembly applications where even minor vibrations can affect product quality or measurement accuracy.

What technical specifications should engineers consider when selecting anti-vibration plug hoses?

Selection of anti-vibration plug hoses requires evaluation of operating pressure range typically up to 10 bar, port connection sizes such as the SHA-3-2R and SHA-3-3R variants offering different bore diameters, and rubber compound compatibility with specific pneumatic media. Engineers must assess the coupling's vibration damping coefficient, which directly impacts noise reduction performance in decibels, alongside flow capacity measured in liters per minute at standard conditions. The quick-connect mechanism's engagement force and disconnection safety features are equally critical for applications requiring frequent coupling changes while maintaining system pressure integrity.

Which international standards apply to anti-vibration plug hoses in pneumatic systems?

Anti-vibration plug hoses must comply with ISO 4414 for pneumatic fluid power safety requirements and ISO 5676 for quick-action couplings dimensional specifications to ensure proper system integration. The rubber compounds typically meet ISO 1629 classification standards for synthetic rubber materials, while the coupling mechanisms conform to DIN 3489 specifications for pneumatic quick-connect fittings. Additional compliance with EN 983 acoustic emission standards may be required in applications where noise reduction performance must be quantified, particularly in manufacturing environments subject to occupational noise regulations.

How do the SHA-3-2R and SHA-3-3R anti-vibration plug hose variants differ?

The SHA-3-2R and SHA-3-3R anti-vibration plug hoses differ primarily in their internal bore diameter and corresponding flow capacity, with the numerical designation indicating the connection port size configuration. The SHA-3-2R features a smaller bore optimized for lower flow applications requiring maximum vibration damping efficiency, while the SHA-3-3R provides increased flow capacity for higher volume pneumatic circuits. Both variants utilize identical rubber compound construction and quick-connect coupling mechanisms, but the larger bore SHA-3-3R typically exhibits slightly reduced vibration attenuation due to the increased internal volume and mass flow dynamics.

What installation requirements and system compatibility factors apply to anti-vibration plug hoses?

Anti-vibration plug hoses require straight-line installation with minimum bend radius of 5 times the hose diameter to preserve damping characteristics and prevent premature coupling failure. System compatibility demands verification of thread specifications, typically NPT or metric ISO 228 connections, alongside pressure rating matching to prevent coupling separation under maximum system pressure. The quick-connect mechanism necessitates adequate clearance space for manual engagement and disconnection, while the rubber construction requires chemical compatibility assessment with pneumatic media including compressed air, inert gases, and synthetic lubricants commonly used in industrial pneumatic systems.

What are the safety ratings and operating parameter limits for anti-vibration plug hoses?

Anti-vibration plug hoses typically operate safely within pressure ranges up to 10 bar maximum working pressure with temperature limits from -20°C to +60°C for standard rubber compounds. The coupling mechanism incorporates automatic shut-off valves meeting safety factor requirements of 4:1 minimum against burst pressure to prevent accidental disconnection under system pressure. While specific IP ratings are not typically assigned to pneumatic couplings, the rubber construction provides inherent moisture resistance, and the quick-connect design ensures reliable sealing performance when properly engaged according to manufacturer torque specifications.

What maintenance schedule and service life expectations apply to anti-vibration plug hoses?

Anti-vibration plug hoses require quarterly visual inspection for rubber deterioration, coupling mechanism wear, and seal integrity, with particular attention to crack formation at stress concentration points near the quick-connect interface. Service life typically ranges from 3 to 5 years under normal operating conditions, though frequent coupling/uncoupling cycles may reduce longevity to 50,000 engagement cycles depending on system pressure and ambient conditions. Replacement indicators include visible rubber hardening, reduced vibration damping performance measured through accelerometer testing, or coupling mechanism looseness that allows pressure drop during system operation beyond acceptable limits.