HSP DC Cupla

Quick couplings

The Nitto Kohki HSP DC Cupla is a steel quick coupling with NBR seal for pressure-assisted mating (DC: Double-Check). The programme covers 12 items in plug (HP-DC) and socket (HS-DC) configurations in nominal sizes 2, 3, 4, 6, 66, and 8. The DC mechanism allows connection and disconnection under residual pressure without first depressurising the circuit.

DC mechanism (Double-Check) - connect and disconnect under residual pressure without prior depressurisation
Steel body, NBR seal - for compressed air and oil-mist air in industrial service
Nominal sizes 2, 3, 4, 6, 66, 8 - 12 items in HP-DC (plug) and HS-DC (socket)
Short cycle times - no waiting for pressure bleed-off during line changes

Nominal sizePlug (HP-DC)Socket (HS-DC)MaterialSeal
22HP-DC2HS-DCSteelNBR
33HP-DC3HS-DCSteelNBR
44HP-DC4HS-DCSteelNBR
66HP-DC6HS-DCSteelNBR
6666HP-DC-SteelNBR
88HP-DC-SteelNBR

Typical applications: Compressed-air systems with frequent quick-change operations under working pressure, production lines with short cycle times, pneumatic component test benches, mobile compressed-air supplies, and installations where pressure bleed-off time would reduce productivity.

Technical data from the manufacturer catalogue

SeriesHSP-DC CUPLA
Body materialSpecial steel (Nickel plated)
Seal materialNitrile rubber (NBR)
Max working pressure20.6 MPa {210 kgf/cm2}
Working temperatureNitrile rubber (NBR): -20 to +80 deg C
Valve structureTwo-way shut-off
Applicable fluidsHydraulic oil
Vacuum serviceAt 1.3x10-1 Pa {1x10-3 mmHg}: socket only -, plug only -, when connected Operational
Size range1/4 inch to 1 inch (applicable pipe size 1/4 inch, 3/8 inch, 1/2 inch, 3/4 inch, 1 inch)
Catalogue pageC01en-b, 158

Operating principle

Two-way shut-offTwo-way shut-offshut-off valve in socketshut-off valve in plugSocketPlugFlow direction: socket to plug
Both halves close on disconnection, so the line contents are retained on both sides.
Connecting in three stepsConnecting in three steps1. Pull the sleeve back2. Push the plug fully home3. Release the sleeve, balls lockSingle hand operation. Depressurise the line before disconnecting.
Connecting sequence of a ball locking quick connect coupling.
  • For various applications with large pressure fluctuations.
  • "Electroless nickel phosphor plating" which is not soluble to fire-resistant "water glycol type hydraulic fluid" is entirely adopted.
  • Valve material with high impact resistance. Available for die casting machines with large pressure fluctuations.
  • Various thread sizes available.
  • How to distinguish from HSP CUPLA: the DC mark is engraved on the flat part of the plug and the flat part of the socket to distinguish from HSP CUPLA.

All models of the series

HP - Female thread

ModelCoupling partApplicationTotal (g)LCTøH (WAF)øøD
2HP-DCPlugR 1/4403217.5Rc 1/4Hex.1920.5
3HP-DCPlugR 3/8683822.5Rc 3/8Hex.2325
4HP-DCPlugR 1/21244427.5Rc 1/2Hex.2932
6HP-DCPlugR 3/41485027.5Rc 3/4Hex.3235
66HP-DCPlugR 3/42325128Rc 3/43540
8HP-DCPlugR 13616136Rc 14147

HS - Female thread

ModelCoupling partApplicationTotal (g)LTøH (WAF)øøD
2HS-DCSocketR 1/413449Rc 1/41927.5
3HS-DCSocketR 3/822660Rc 3/823(33)
4HS-DCSocketR 1/248572Rc 1/235(43)
6HS-DCSocketR 3/446072Rc 3/435(43)
66HS-DCSocketR 3/456978.5Rc 3/43547
8HS-DCSocketR 11,04293Rc 146(58)

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

SeriesMax working pressureSize rangeValve structureApplicable fluids
HSP-DC CUPLA206 bar1/4 inch to 1 inch (applicable pipe size 1/4 inch, 3/8 inch, 1/2 inch, 3/4 inch, 1 inch)Two-way shut-offHydraulic oil
FLATFACE CUPLA F35350 barThread 1/4 inch, 3/8 inch, 1/2 inch, 3/4 inch, 1 inchTwo-way shut-off (Spill Reduction)Hydraulic oil
FLATFACE CUPLA FF350 bar3/8 inch, 1/2 inch, 3/4 inch, 1 inch (thread)Two-way shut-off (Spill Reduction)Hydraulic oil
In-Line PURGE ADAPTER350 barPAD-2: R 1/4. PAD-3FM: R 3/8 x Rc 3/8. PAD-4FM: R 1/2 x Rc 1/2. PAD-6FM: R 3/4 x Rc 3/4. PAD-8FM: R 1 x Rc 1.-Hydraulic oil

Pick HSP-DC CUPLA when the line carries hydraulic oil at up to 20.6 MPa {210 kgf/cm2}; every sibling series listed in this group is rated at 1.0 to 1.5 MPa {10 to 15 kgf/cm2} and is not usable at that level. Of those siblings only COMPACT ZEROSPILL CUPLA also shuts off on both sides, and it does so at 1.0 MPa {10 kgf/cm2}, while HI CUPLA BL, NUT CUPLA, LOCK CUPLA 200, HI CUPLA Two Way Type, PURGE HI CUPLA, PURGE LINE CUPLA and the ROTARY models are one-way shut-off. Where 1.5 MPa {15 kgf/cm2} is sufficient and a one-way shut-off is acceptable, one of those series is the simpler choice.

Body and seal materials

Body material
Special steel (Nickel plated)
Seal materialMarkWorking temperatureRemarks
Nitrile rubber (NBR)--20 to +80 deg C-

Further catalogue data

NoteValue
Maximum tightening torque, thread 1/4 inch28 Nm {286 kgf-cm}
Maximum tightening torque, thread 3/8 inch45 Nm {459 kgf-cm}
Maximum tightening torque, thread 1/2 inch90 Nm {918 kgf-cm}
Maximum tightening torque, thread 3/4 inch100 Nm {1020 kgf-cm}
Maximum tightening torque, thread 1 inch180 Nm {1836 kgf-cm}
Flow directionFluid flow can be bi-directional when socket and plug are connected.
Minimum cross-sectional area (mm2), 2HS-DC x 2HP-DC21
Minimum cross-sectional area (mm2), 3HS-DC x 3HP-DC37
Minimum cross-sectional area (mm2), 4HS-DC x 4HP-DC77
Minimum cross-sectional area (mm2), 6HS-DC x 6HP-DC77
Minimum cross-sectional area (mm2), 66HS-DC x 66HP-DC145
Minimum cross-sectional area (mm2), 8HS-DC x 8HP-DC203
Admixture of air on connection (mL), 2HS-DC x 2HP-DC0.7
Admixture of air on connection (mL), 3HS-DC x 3HP-DC1.9
Admixture of air on connection (mL), 4HS-DC x 4HP-DC3.5
Admixture of air on connection (mL), 6HS-DC x 6HP-DC3.5
Admixture of air on connection (mL), 66HS-DC x 66HP-DC8.2
Admixture of air on connection (mL), 8HS-DC x 8HP-DC12.4
Flow rateFlow Rate - Pressure Loss Characteristics chart on page 159. [Test conditions] -Fluid : Hydraulic oil -Temperature : 35 deg C +/-5 deg C -Fluid viscosity : 32x10-6 m2/s -Density : 0.87x103 kg/m3. Curves plotted: 2HS-DC x 2HP-DC, 3HS-DC x 3HP-DC, 4HS-DC x 4HP-DC, 6HS-DC x 6HP-DC, 66HS-DC x 66HP-DC, 8HS-DC x 8HP-DC. Pressure loss in MPa {kgf/cm2} from 0.01 {0.1} to 1.0 {10} against flow rate in L/min from 1 to 1000.

Interchangeability and size groups

Interchangeable with standard HSP CUPLA plug or socket in the same size. Use HSP-DC CUPLA for die-casting machines with large pressure fluctuations. The "DC" mark is engraved on the hex. part of the plug and the flat part of the socket to distinguish from HSP CUPLA. Note printed with the model table: 4HSP with 6HSP can be connected with each other whereas 6HSP with 66HSP cannot be connected.

Safety and application notes

  • 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 158. The complete catalogue is available for download on this page.

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  1. Quick connect coupling HSP DC Cupla 6HS-DC, steel - Nitto Kohki 369821610
    €143.78