The Nitto Kohki 450B Cupla is a high-pressure quick coupling in steel with NBR seals, designed for operating pressures up to 450 bar. The range includes a plug (450B-3P) and a socket (450B-3S) in nominal size 3. The steel body with NBR elastomer seal allows use with hydraulic oils and comparable fluids in test and industrial equipment.
| Type | Design | Nominal size | Material | Seal |
|---|---|---|---|---|
| 450B-3P | Plug | 3 | Steel | NBR |
| 450B-3S | Socket | 3 | Steel | NBR |
Typical applications: Hydraulic test benches and medium-to-high-pressure test lines, machine tools with high-pressure coolant circuits, pressure-testing systems for pipelines and fittings, and laboratory equipment for pressure measurements up to 450 bar.
Technical data from the manufacturer catalogue
| Series | 450B CUPLA |
|---|---|
| Body material | Special steel (Nickel plated) |
| Seal material | NBR (Nitrile rubber), FKM (Fluoro rubber) |
| Max working pressure | 44.1 MPa {450 kgf/cm2} |
| Working temperature | NBR (Nitrile rubber), standard material: -20 °C to +80 °C | FKM (Fluoro rubber), made-to-order item: -20 °C to +180 °C |
| Valve structure | Two-way shut-off |
| Applicable fluids | Hydraulic oil |
| Vacuum service | Suitability for vacuum 1.3 Pa {1x10-2 mmHg}: socket only -, plug only -, when connected Operational |
| Size range | 3/8 inch |
| Catalogue page | C01en-b, 111 |
Operating principle
- Metal-touch valve system with superior durability.
- Separation prevention mechanism gives secure connection.
- CUPLA for higher working pressure up to 44.1 MPa {450 kgf/cm2}.
- Separation prevention mechanism is easily locked by turning the sleeve after connection.
- Both socket and plug have metal-touch automatic shut-off valves that prevent fluid spill out on disconnection.
All models of the series
P - Female thread
| Model | Coupling part | Application | Steel (g) | L | øD | C | T | øH(WAF) |
|---|---|---|---|---|---|---|---|---|
| 450B-3P | Plug | R 3/8 | 95 | 37.5 | 28 | 22.5 | Rc 3/8 | 24 |
S - Female thread
| Model | Coupling part | Application | Steel (g) | L | øD | T | øH(WAF) |
|---|---|---|---|---|---|---|---|
| 450B-3S | Socket | R 3/8 | 285 | 59.5 | (36) | Rc 3/8 | 24 |
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 |
|---|---|---|---|---|
| 210 CUPLA | 206 bar | 1/4 inch to 1 inch | Two-way shut-off | Hydraulic oil |
| HSP CUPLA | 206 bar | 1/4 inch, 3/8 inch, 1/2 inch, 3/4 inch, 1 inch, 1 1/4 inch, 1 1/2 inch, 2 inch | Two-way shut-off | Hydraulic oil |
| HYPER HSP CUPLA | 206 bar | 1/4 inch, 3/8 inch, 1/2 inch, 3/4 inch, 1 inch | Two-way shut-off | Hydraulic oil |
| HSU CUPLA | 210 bar | Thread 1/4 inch, 3/8 inch, 1/2 inch, 3/4 inch, 1 inch | Two-way shut-off | Water, Hydraulic oil, Gas |
| 280 CUPLA | 315 bar | Thread 1/4 inch, 3/8 inch, 1/2 inch, 3/4 inch, 1 inch | Two-way shut-off | Hydraulic oil |
| 350 CUPLA | 345 bar | Thread 1/4 inch, 3/8 inch, 1/2 inch, 3/4 inch, 1 inch, 1 1/4 inch, 1 1/2 inch | Two-way shut-off (Spill Reduction) | Hydraulic oil |
| 450B CUPLA | 441 bar | 3/8 inch | Two-way shut-off | Hydraulic oil |
| 700R CUPLA | 686 bar | Thread 3/8 inch, 1/2 inch | Two-way shut-off | Hydraulic oil |
Choose 450B CUPLA when the hydraulic line works above the 34.5 MPa {352 kgf/cm2} of 350 CUPLA and the 27.5 to 31.5 MPa {281 to 321 kgf/cm2} of 280 CUPLA, but does not need the 68.6 MPa {700 kgf/cm2} of 700R CUPLA. All of these series shut off on both sides, so the deciding factors are the working pressure of 44.1 MPa {450 kgf/cm2} and the single catalogue size of 3/8 inch. For circuits in the 20.6 MPa {210 kgf/cm2} class, HSP CUPLA, HYPER HSP CUPLA, 210 CUPLA, S210 CUPLA or HSU CUPLA already cover the requirement.
Body and seal materials
| Body material |
|---|
| Special steel (Nickel plated) |
| Seal material | Mark | Working temperature | Remarks |
|---|---|---|---|
| NBR (Nitrile rubber), standard material | - | -20 °C to +80 °C | - |
| FKM (Fluoro rubber), made-to-order item | - | -20 °C to +180 °C | - |
Further catalogue data
| Note | Value |
|---|---|
| Working pressure by unit | 44.1 MPa / 450 kgf/cm2 / 441 bar / 6400 PSI |
| Size (Thread) | 3/8 inch |
| Stand-alone leakage rate on either socket or plug | 0.1 mL/min at 0.3 MPa {3 kgf/cm2} |
| Maximum tightening torque | 40 {408} Nm {kgf cm} |
| Minimum cross-sectional area | 37 mm2 |
| Admixture of air on connection, volume of air admixture | 1.43 mL |
| Flow direction | Fluid flow can be bi-directional when socket and plug are connected. |
| Flow rate | Flow rate - pressure loss characteristics diagram is printed for 450B-3SP (flow rate 1 to 100 L/min, pressure loss 0.001 to 1.0 MPa {0.01 to 10 kgf/cm2}). Test conditions: fluid hydraulic oil, temperature 25 deg C +/-5 deg C, fluid viscosity 32x10-6 m2/s, density 0.87x103 kg/m3. |
Interchangeability and size groups
There is no interchangeability between 450B CUPLA and HSP CUPLA, 210 CUPLA or 280 CUPLA. Do not connect each other even if some sizes are approximate.
Safety and application notes
- Precautions for use: There is no interchangeability between 450B CUPLA and HSP CUPLA, 210 CUPLA or 280 CUPLA. Do not connect each other even if some sizes are approximate.
- 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 111. The complete catalogue is available for download on this page.
