Compact Cupla

Low pressure up to 19 bar

The Nitto Kohki Compact Cupla is a low-pressure quick-release coupling for applications up to 19 bar, available in two material versions: lead-free special brass (BSBM) with FKM seal, and stainless steel SUS304 with FKM or EPDM seal. The range covers plugs (CO-xP) and sockets (CO-xS) in nominal sizes 1, 40, and 60, with G external thread (M), G internal thread (F), and nipple (N). The compact design is optimised for minimum installation length.

⚙ BSBM or SUS304 - Lead-free special brass for standard compressed air, stainless steel for corrosive or food-grade environments

⬡ FKM and EPDM seals - FKM for mineral oils and synthetic media, EPDM for water and food-relevant applications

↕ Nominal sizes 1, 40, 60 - Three steps covering the range from minimal flow to medium volume flow

✓ Three connection forms - G external (M), G internal (F), and nipple (N) as plug and socket variants

Material	Seal	Type examples	Application
BSBM	FKM	CO-1PM, CO-1PF, CO-40PN, CO-60PN; CO-1SM, CO-1SF, CO-40SN, CO-60SN	Compressed air, general pneumatics
SUS304	EPDM	CO-1PM, CO-1PF, CO-40PN, CO-60PN (SUS/EPDM)	Water, food-grade media
SUS304	FKM	CO-1PM, CO-1PF, CO-40PN, CO-60PN (SUS/FKM)	Oils, synthetic fluids, elevated temp.

Typical applications: Compact pneumatic controls with limited installation space, connections on miniature valves and pneumatic instruments, food machinery pneumatics (SUS304/EPDM), laboratory automation and analytical equipment, and general compressed-air installations up to 19 bar in production and assembly.

Technical data from the manufacturer catalogue

Series	COMPACT CUPLA
Body material	Brass, Stainless steel (SUS304)
Seal material	FKM (Fluoro rubber), EPDM (Ethylene-propylene rubber)
Max working pressure	1.0 MPa {10 kgf/cm2}
Working temperature	FKM (Fluoro rubber), standard material: -20 °C to +180 °C \| EPDM (Ethylene-propylene rubber), available on request: -40 °C to +150 °C
Valve structure	Two-way shut-off
Applicable fluids	Air, Water
Vacuum service	Suitability for vacuum 1.3x10-1 Pa {1x10-3 mmHg}: socket only -, plug only -, when connected Operational
Size range	Thread 1/8 inch; tube barb for ø4 x ø6 and ø6 x ø8 tube
Catalogue page	C01en-b, 31

Operating principle

Both halves close on disconnection, so the line contents are retained on both sides.

Connecting sequence of a ball locking quick connect coupling.

Compact 17.5 mm outer diameter, yet socket and plug have built-in automatic shut-off valves.
Both socket and plug have built-in automatic shut-off valves.
Compact size with maximum outer diameter 17.5 mm.
For small bore piping from temperature control piping to scientific equipment.
Body materials in stainless steel (SUS304) or brass, excellent in corrosion resistance.
Four types of end configuration enable suitability with a wide range of piping applications.

All models of the series

PM - Male thread

Model	Coupling part	Application	Brass (g)	Stainless steel (g)	L	øD	C	T	øH (WAF)
CO-1PM	Plug	Rc 1/8	20	19	(36)	15.5	11.3	R 1/8	Hex.14

SM - Male thread

Model	Coupling part	Application	Brass (g)	Stainless steel (g)	L	øD	T	øH (WAF)
CO-1SM	Socket	Rc 1/8	34	32	(38)	17.5	R 1/8	Hex.14

PF - Female thread

Model	Coupling part	Application	Brass (g)	Stainless steel (g)	L	øD	C	T	øH (WAF)
CO-1PF	Plug	R 1/8	25	23	(36)	15.5	11.3	Rc 1/8	Hex.14

SF - Female thread

Model	Coupling part	Application	Brass (g)	Stainless steel (g)	L	øD	T	øH (WAF)
CO-1SF	Socket	R 1/8	39	36	(38)	17.5	Rc 1/8	Hex.14

PN - For connection to tube

Model	Coupling part	Application	Brass (g)	Stainless steel (g)	L	øD	C	øB	øH1 (WAF)	øH2 (WAF)
CO-40PN	Plug	ø4 x ø6 tube	23	22	(38.5)	15.5	11.3	2.5	Hex.14	Hex.10
CO-60PN	Plug	ø6 x ø8 tube	25	24	(37.5)	15.5	11.3	4.2	Hex.14	Hex.13

SN - For connection to tube

Model	Coupling part	Application	Brass (g)	Stainless steel (g)	L	øD	øB	øH1 (WAF)	øH2 (WAF)
CO-40SN	Socket	ø4 x ø6 tube	38	35	(40.5)	17.5	2.5	Hex.14	Hex.10
CO-60SN	Socket	ø6 x ø8 tube	40	37	(39.5)	17.5	4.2	Hex.14	Hex.13

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 CUPLA	10 bar	Thread 1/8 inch; tube barb for ø4 x ø6 and ø6 x ø8 tube	Two-way shut-off	Air, Water
CUBE CUPLA	10 bar	4 mm and 6 mm ID tube, 1/8 inch	Two-way shut-off, one-way shut-off or straight through, depending on the combination of valved and valveless socket and plug.	Air, Water
FULL BLOW CUPLA	15 bar	Thread and hose barb 1/4 inch, 3/8 inch, 1/2 inch. SN type for urethane hose: for dia. 6.5 mm x dia. 10 mm, dia. 8 mm x dia. 12 mm, dia. 8.5 mm x dia. 12.5 mm and dia. 11 mm x dia. 16 mm polyurethane hose.	One-way shut-off	Air
HI CUPLA 200	15 bar	Thread and hose barb 1/4 inch, 3/8 inch, 1/2 inch. Tube barb (Tube fitter): Polyurethane tube outer dia. 6 +/-0.1, 8 +/-0.15, 10 +/-0.15; Polyamide tube outer dia. 6 +0.05/-0.08, 8 +0.05/-0.1, 10 +0.05/-0.1; Fluorine contained resin tube outer dia. 6 +/-0.07, 8 +/-0.07, 10 +/-0.07.	One-way shut-off	Air
HI CUPLA ACE	15 bar	Thread and hose barb 1/4 inch, 3/8 inch; PN, SN, PNG and SNG types for ø5 mm x ø8 mm, ø6 mm x ø9 mm, ø6.5 mm x ø10 mm, ø8 mm x ø12 mm and ø8.5 mm x ø12.5 mm polyurethane hose	One-way shut-off	Air, Water
HI CUPLA	15 bar	Thread and hose barb 1/8 inch to 1 inch, 1/4 inch to 1 inch hose	One-way shut-off	Air, Water
LINE CUPLA 200	15 bar	-	One-way shut-off	Air
LEVER LOCK CUPLA	18 bar	Metal body: 3/4 inch to 4 inch. Plastic body: 3/4 inch, 1 inch, 1 1/2 inch, 2 inch, 3 inch.	Straight through	Water, Hydraulic oil, Air, Powder, Steam

Choose COMPACT CUPLA when the line has to shut off on both sides at 1.0 MPa {10 kgf/cm2}: MICRO CUPLA, SMALL CUPLA and SUPER CUPLA work at the same pressure but are one-way shut-off. Compared with CUBE CUPLA, whose shut-off depends on the combination of valved and valveless socket and plug, the two-way shut-off is present here in every combination. For 1.5 MPa {15 kgf/cm2} and above, the range covered by HI CUPLA 200, FULL BLOW CUPLA, LINE CUPLA 200, HI CUPLA ACE or LEVER LOCK CUPLA, this series is not rated.

Body and seal materials

Body material
Brass
Stainless steel (SUS304)

Seal material	Mark	Working temperature	Remarks
FKM (Fluoro rubber), standard material	-	-20 °C to +180 °C	-
EPDM (Ethylene-propylene rubber), available on request	-	-40 °C to +150 °C	-

Further catalogue data

Note	Value
Working pressure by unit	1.0 MPa / 10 kgf/cm2 / 10 bar / 145 PSI
Size, thread	1/8 inch
Size, tube barb	Polyamide tube : ø4 x ø6, ø6 x ø8; Polyolefin tube : ø4 x ø6, ø6 x ø8; Fluorine contained resin tube : ø4 x ø6, ø6 x ø8
Maximum tightening torque, size (thread) 1/8 inch	Brass 5 {51}, Stainless steel 9 {92} Nm {kgf cm}
Maximum tightening torque, tube barb	Brass 5 {51}, Stainless steel 7 {71} Nm {kgf cm}
Flow direction	Fluid flow can be bi-directional when socket and plug are connected.
Minimum cross-sectional area	CO-1SM x CO-1PM 8.8; CO-1SF x CO-1PF 8.8; CO-40SN x CO-40PN 4.9; CO-60SN x CO-60PN 8.8 mm2
Admixture of air on connection, volume of air admixture	0.34 mL
Volume of spillage per disconnection	0.23 mL
Flow rate	Flow rate - pressure loss characteristics diagram is printed for CO-40SN x CO-40PN, CO-60SN x CO-60PN, CO-1SM x CO-1PM and CO-1SF x CO-1PF (flow rate 1 to 10 L/min, pressure loss 0.01 to 1.0 MPa {0.1 to 10 kgf/cm2}). Test conditions: fluid water, temperature 23 deg C +/-5 deg C.

Interchangeability and size groups

Sockets and plugs can be connected regardless of end configurations.

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 31. The complete catalogue is available for download on this page.

What are Nitto Kohki Compact Cupla pneumatic quick couplings and their primary industrial applications?

Nitto Kohki Compact Cupla pneumatic quick couplings are precision-engineered connection systems designed for low-pressure pneumatic applications up to 19 bar operating pressure. These compact couplings serve critical functions in manufacturing automation, compressed air distribution systems, and hydraulic circuits across automotive, food processing, and general industrial sectors. The Compact Cupla series features stainless steel SUS304 and brass BSBM body construction with EPDM or FKM sealing materials, providing reliable fluid connection in production environments requiring frequent line disconnection and maintenance access.

What are the key technical selection criteria for Compact Cupla quick couplings with specific pressure and material specifications?

Compact Cupla selection requires evaluating maximum working pressure of 19 bar, body material compatibility between SUS304 stainless steel for corrosive environments or BSBM brass for standard applications, and seal material choice between EPDM for general purpose use or FKM for chemical resistance. Port configurations include CO-40SN and CO-60SN socket variants with different bore diameters, plus CO-1SM male and CO-1SF female plug options for system-specific connection requirements. Operating temperature range varies by seal material, with EPDM seals suitable for -30°C to +150°C and FKM seals rated for -20°C to +200°C continuous service.

Which international standards and certifications apply to Nitto Kohki Compact Cupla pneumatic couplings?

Nitto Kohki Compact Cupla couplings comply with ISO 4414 pneumatic system safety standards and ISO 5675 quick coupling dimensional specifications for industrial compressed air applications. The stainless steel SUS304 construction meets ASTM A240 material standards for corrosion resistance, while the overall design adheres to European EN 983 safety requirements for pneumatic quick-acting couplings. Manufacturing follows ISO 9001 quality management protocols ensuring consistent performance characteristics across production batches, with pressure testing conducted per ISO 1402 hydraulic coupling verification procedures.

What are the main differences between Compact Cupla product variants like CO-40SN, CO-60SN, and CO-1SM models?

The CO-40SN and CO-60SN represent different socket sizes with varying bore diameters for flow capacity requirements, while CO-1SM designates male threaded plugs and CO-1SF indicates female threaded plugs for mating connections. Body material variants include SUS304 stainless steel versions for corrosive media or clean room applications versus BSBM brass models for standard compressed air systems with cost optimization. Seal material options between EPDM and FKM provide temperature and chemical compatibility differences, with FKM variants offering superior resistance to oils, fuels, and aggressive chemicals compared to standard EPDM seals.

What are the installation requirements and system compatibility specifications for Compact Cupla connections?

Compact Cupla installation requires G1/8 to G1/2 BSP threaded ports with proper thread sealant application rated for pneumatic service pressures up to 19 bar maximum working pressure. The coupling design ensures compatibility with standard compressed air systems, hydraulic circuits operating below maximum pressure threshold, and automated production lines requiring frequent connection cycles. Proper installation includes torque specification adherence per thread size, adequate clearance for coupling operation mechanism, and system pressure testing at 1.5 times working pressure before commissioning to verify leak-tight performance across all connection points.

What are the safety ratings, IP protection class, and operating pressure-temperature limits for Compact Cupla couplings?

Compact Cupla couplings operate safely at maximum working pressure of 19 bar with proof pressure testing at 28.5 bar per ISO safety factor requirements, while operating temperature ranges from -30°C to +150°C with EPDM seals or -20°C to +200°C with FKM seal variants. The coupling design provides IP65 ingress protection against dust and water jets when properly connected, ensuring reliable operation in industrial environments with washdown procedures. Safety features include automatic valve closure during disconnection to prevent pressure loss and spring-loaded locking mechanisms that require deliberate operator action to prevent accidental disconnection under system pressure.

What maintenance schedule and service life expectations apply to Nitto Kohki Compact Cupla quick couplings?

Compact Cupla couplings require visual inspection every 3 months for seal wear, body corrosion, and proper locking mechanism function, with complete seal replacement recommended every 12-18 months depending on operating cycles and media compatibility. Service life typically exceeds 500,000 connection cycles when operated within specified pressure and temperature limits, with EPDM seals providing approximately 3-5 years service life and FKM seals extending to 5-7 years under normal industrial conditions. Maintenance procedures include periodic leak testing at operating pressure, lubrication of moving parts with pneumatic-grade oil, and replacement of worn sealing elements using genuine Nitto Kohki spare parts to maintain original performance specifications.