HSU Cupla
High-Pressure up to 700 Bar
The Nitto Kohki HSU Cupla is a high-pressure quick coupling manufactured in stainless steel (SUS) with HNBR seals, designed for use in high-pressure service. The range comprises 10 items in nominal sizes 2, 3, 4, 6 and 8, each available as plug (P) and socket (S). The stainless body combined with HNBR (hydrogenated nitrile rubber) seals gives this series enhanced resistance to aggressive media, temperature variation and corrosive environments.
| Criterion | Option |
|---|---|
| Nominal sizes | 2, 3, 4, 6, 8 |
| Connector types | P (plug), S (socket) |
| Part numbers | HSU-2P, HSU-3P, HSU-4P, HSU-6P, HSU-8P (plugs); HSU-2S, HSU-3S, HSU-4S, HSU-6S, HSU-8S (sockets) |
| Body material | Stainless steel (SUS) |
| Seal material | HNBR (hydrogenated nitrile rubber) |
| Application group | High pressure up to 700 bar |
Typical applications: High-pressure hydraulic systems handling corrosive or aggressive media, offshore and marine installations with elevated corrosion requirements, cleanroom and food-processing applications mandating stainless steel, test rigs with cyclic high-pressure loading, and processes operating at elevated temperatures where HNBR is preferred over NBR.
Technical data from the manufacturer catalogue
| Series | HSU CUPLA |
|---|---|
| Body material | Stainless steel (SUS304) |
| Seal material | Hydrogenated nitrile rubber (HNBR) |
| Max working pressure | 21.0 MPa {214 kgf/cm2, 210 bar, 3050 PSI} |
| Working temperature | Hydrogenated nitrile rubber (HNBR): -20 °C to +120 °C |
| Valve structure | Two-way shut-off |
| Applicable fluids | Water, Hydraulic oil, Gas |
| Vacuum service | 1.3x10-1 Pa {1x10-3 mmHg}: socket only not applicable, plug only not applicable, operational when connected. |
| Size range | Thread 1/4 inch, 3/8 inch, 1/2 inch, 3/4 inch, 1 inch |
| Catalogue page | C01en-b, 99 |
Operating principle
- Body material is excellent corrosion resistant stainless steel (SUS304). Suitable for use in tough/harsh environments such as offshore applications.
- Separation prevention mechanism is easily locked by turning the sleeve after connection.
- Despite having a stainless steel body, the working pressure, 21.0 MPa, of HSU CUPLA is comparable to that of special steel body CUPLA such as HSP CUPLA series.
- Both socket and plug have built-in automatic shut-off valves that prevent fluid outflow on disconnection.
- Hydrogenated nitrile rubber (HNBR) is used as a seal material for wide variety of liquids.
- The flow volume is increased by between 14 to 44% while at the same time the coupled length is reduced by at least 10% compared with the S210 CUPLA.
- Easy to operate separation prevention mechanism enhances operator safety.
- Align the cutout in the sleeve with the ball stopper, and pull the sleeve to connect the plug.
All models of the series
P - Female thread
| Model | Coupling part | Application | Stainless steel (g) | L | øD | C | T | øH (WAF) |
|---|---|---|---|---|---|---|---|---|
| HSU-2P | Plug | R 1/4 | 49 | 45.5 | 21 | 27.5 | Rc 1/4 | Hex.19 |
| HSU-3P | Plug | R 3/8 | 86 | 51.5 | 26.5 | 32 | Rc 3/8 | Hex.24 |
| HSU-4P | Plug | R 1/2 | 152 | 59 | 33 | 39 | Rc 1/2 | Hex.30 |
| HSU-6P | Plug | R 3/4 | 295 | 74 | 42 | 51.5 | Rc 3/4 | Hex.38 |
| HSU-8P | Plug | R1 | 481 | 83 | 51 | 58 | Rc 1 | Hex.46 |
S - Female thread
| Model | Coupling part | Application | Stainless steel (g) | L | øD | T | øH (WAF) |
|---|---|---|---|---|---|---|---|
| HSU-2S | Socket | R 1/4 | 142 | 63 | 28 | Rc 1/4 | 19 |
| HSU-3S | Socket | R 3/8 | 255 | 71.5 | 35 | Rc 3/8 | 24 |
| HSU-4S | Socket | R 1/2 | 479 | 84 | 45 | Rc 1/2 | 30 |
| HSU-6S | Socket | R 3/4 | 953 | 106 | 55 | Rc 3/4 | 38 |
| HSU-8S | Socket | R1 | 1432 | 118 | 65 | Rc 1 | 46 |
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 HSU CUPLA when a line up to 21.0 MPa {214 kgf/cm2} also demands corrosion resistance: it delivers that working pressure from a stainless steel (SUS304) body and is comparable to special steel body series such as HSP CUPLA, which is rated 14.0 to 20.6 MPa {142 to 210 kgf/cm2}. Against the S210 CUPLA at 20.6 MPa {210 kgf/cm2} it adds 14 to 44% more flow volume and at least 10% less coupled length. Above 21.0 MPa the 280 CUPLA, 350 CUPLA, 450B CUPLA and 700R CUPLA cover the higher ratings and are likewise two-way shut-off.
Body and seal materials
| Body material |
|---|
| Stainless steel (SUS304) |
| Seal material | Mark | Working temperature | Remarks |
|---|---|---|---|
| Hydrogenated nitrile rubber | HNBR | -20 °C to +120 °C | - |
Further catalogue data
| Note | Value |
|---|---|
| Working pressure | 21.0 MPa / 214 kgf/cm2 / 210 bar / 3050 PSI |
| Flow direction | Fluid flow can be bi-directional when socket and plug are connected. |
| Maximum tightening torque, Nm {kgf.cm} | 1/4 inch 28 {286}, 3/8 inch 35 {357}, 1/2 inch 70 {714}, 3/4 inch 100 {1020}, 1 inch 180 {1836} |
| Minimum cross-sectional area (mm2) | HSU-2SP 27.1, HSU-3SP 48.2, HSU-4SP 84.2, HSU-6SP 143.6, HSU-8SP 221.2 |
| Admixture of air on connection (mL) | HSU-2SP 0.7, HSU-3SP 1.5, HSU-4SP 3.6, HSU-6SP 6.3, HSU-8SP 10.9. May vary depending upon the usage conditions. |
| Volume of spillage per disconnection (mL) | HSU-2SP 0.6, HSU-3SP 1.7, HSU-4SP 3.0, HSU-6SP 6.8, HSU-8SP 11.2. May vary depending upon the usage conditions. |
| Suitability for vacuum, degree | 1.3x10-1 Pa {1x10-3 mmHg} |
| Suitability for vacuum, socket only | Not applicable |
| Suitability for vacuum, plug only | Not applicable |
| Suitability for vacuum, when connected | Operational |
| Separation prevention mechanism | Align the cutout in the sleeve with the ball stopper, and pull the sleeve to connect the plug. Separation prevention mechanism is easily locked by turning the sleeve after connection. Without alignment of the cutout with the ball stopper disconnection cannot be made. The stopper is marked with blue for visual understanding. |
| WAF | WAF stands for width across flats. |
| Flow rate | Flow Rate - Pressure Loss Characteristics charts on page 100. Hydraulic oil chart: test conditions - fluid hydraulic oil, fluid viscosity 32x10-6 m2/s, density 0.87x103 kg/m3; pressure loss in MPa {kgf/cm2} from 0.01 {0.1} to 1.0 {10} against flow rate 1 to 1000 L/min, plotted for HSU-2S x HSU-2P, HSU-3S x HSU-3P, HSU-4S x HSU-4P, HSU-6S x HSU-6P and HSU-8S x HSU-8P. Water chart: pressure loss in MPa {kgf/cm2} from 0.001 {0.01} to 1.0 {10} against flow rate 1 to 1000 L/min, plotted for the same five pairs. The test temperature figures and the individual curve values are not readable in the page text. |
Interchangeability and size groups
Socket and plug of different sizes cannot be connected.
Safety and application notes
- The seal materials used in HSU CUPLA are not suitable for Freon gas.
- Socket and plug of different sizes cannot be connected.
- The operable temperature range depends on the operating conditions.
- Without alignment of the cutout with the ball stopper disconnection cannot be made.
- Before use, please be sure to read 'Safety Guide' described at the end of this book and '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 99. The complete catalogue is available for download on this page.
