SP Cupla Type A

Medium Pressure up to 75 Bar

The Nitto Kohki SP Cupla Type A is a steel quick coupling for medium-pressure service up to 75 bar, covering the widest nominal size range in its group: plugs (P) and sockets (S) in nominal sizes 2, 3, 4, 6, 8, 10, 12 and 16. The 146-item range is available in two seal variants, NBR for general compressed-air and hydraulic duty and FKM (fluoroelastomer) for elevated media and temperature resistance. All types follow the Type-A coupling principle, allowing push-to-connect engagement with automatic valve locking on disconnection.

⚙ Steel body - robust, for general hydraulic and pneumatic duty up to 75 bar

✓ NBR and FKM available - NBR for standard use, FKM for mineral oils, fuels and solvents

⚡ Nominal sizes 2-16 - plug (P-A) and socket (S-A) per size in both seal variants

↕ 146 items - comprehensive stock range covering all sizes and seal materials

✦ Type-A principle - automatic valve locking on disconnection, one-hand operation

Nominal size	Plug NBR	Socket NBR	Plug FKM	Socket FKM
2	2P-A	2S-A	2P-A (FKM)	2S-A (FKM)
3	3P-A	3S-A	3P-A (FKM)	3S-A (FKM)
4	4P-A	4S-A	4P-A (FKM)	4S-A (FKM)
6	6P-A	6S-A	6P-A (FKM)	6S-A (FKM)
8	8P-A	8S-A	8P-A (FKM)	8S-A (FKM)
10	10P-A	10S-A	10P-A (FKM)	10S-A (FKM)
12	12P-A	12S-A	12P-A (FKM)	12S-A (FKM)
16	16P-A	16S-A	16P-A (FKM)	16S-A (FKM)

Typical applications: Hydraulic presses, injection moulding machines and machine tools in the medium-pressure range up to 75 bar, compressed-air systems with quick-change couplings, metalworking coolant lines, chemical plant with mineral oil or fuel contact (FKM variants), and applications that need a broad nominal size range within a unified coupling system.

Technical data from the manufacturer catalogue

Series	SP CUPLA Type A
Body material	Brass, Stainless steel (SUS304), Steel (Nickel plated)
Seal material	Nitrile rubber (NBR), Fluoro rubber (FKM), Ethylene-propylene rubber (EPDM)
Max working pressure	1.5 to 7.5 MPa {15 to 76 kgf/cm2}
Working temperature	Nitrile rubber (NBR): -20 °C to +80 °C \| Fluoro rubber (FKM): -20 °C to +180 °C \| Ethylene-propylene rubber (EPDM): -40 °C to +150 °C
Valve structure	Two-way shut-off
Applicable fluids	Water, Hydraulic oil, Chemicals, Air, Gas, Steam
Vacuum service	1.3x10-1 Pa {1x10-3 mmHg}: socket only -, plug only -, when connected Operational
Size range	1/8 inch to 2 inch
Catalogue page	C01en-b, 85

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.

Automatic shut-off valves in both socket and plug prevent fluid spill out on disconnection.
Available in various standard body materials, sizes and end configurations to cope with diversified applications and operating situations.
Plugs with male thread end are also available.
New self-aligned valve design provides better seal: the new design of the valve head makes smooth self-aligned return to its original position when socket and plug are disconnected. This mechanism enhances safety sealing of individual socket or plug when disconnected (1 to 8SP-A Type).
Fluid flow can be bi-directional when socket and plug are connected.

All models of the series

P-A - Female thread

Model	Coupling part	Application	Steel (g)	Brass (g)	Stainless steel (g)	L	C	T	øH(WAF)
1P-A	Plug	R 1/8	17	19	17	29	19	Rc 1/8	Hex.14
2P-A	Plug	R 1/4	32	34	32	36	22	Rc 1/4	Hex.17
3P-A	Plug	R 3/8	56	61	56	40	25	Rc 3/8	Hex.21
4P-A	Plug	R 1/2	112	121	112	44	28	Rc 1/2	Hex.29
6P-A	Plug	R 3/4	190	205	190	52	36	Rc 3/4	Hex.35
8P-A	Plug	R1	311	333	310	62	40	Rc 1	Hex.41
10P-A	Plug	R 1 1/4	590	630	620	70	45	Rc 1 1/4	Hex.54
12P-A	Plug	R 1 1/2	870	920	880	75	49	Rc 1 1/2	Hex.63
16P-A	Plug	R2	1540	1640	1560	80	52	Rc 2	77×ø84

S-A - Female thread

Model	Coupling part	Application	Steel (g)	Brass (g)	Stainless steel (g)	L	T	øH(WAF)	øøD
1S-A	Socket	R 1/8	73	79	75	48	Rc 1/8	14	24
2S-A	Socket	R 1/4	119	128	130	58	Rc 1/4	19	28
3S-A	Socket	R 3/8	187	202	193	65	Rc 3/8	21	35
4S-A	Socket	R 1/2	368	397	391	72	Rc 1/2	29	45
6S-A	Socket	R 3/4	639	686	645	88	Rc 3/4	35	55
8S-A	Socket	R1	951	1024	962	102	Rc 1	41	65
10S-A	Socket	R 1 1/4	1430	1520	1440	115	Rc 1 1/4	54	77
12S-A	Socket	R 1 1/2	2130	2270	2150	124	Rc 1 1/2	63	88
16S-A	Socket	R2	3280	3510	3310	132	Rc 2	77	108

P-M-A - Male thread

Model	Coupling part	Application	Brass (g)	L	C	T	øH(WAF)
1P-M-A	Plug	Rc 1/8	24	(40)	19	R 1/8	Hex.14
2P-M-A	Plug	Rc 1/4	41	(44)	22	R 1/4	Hex.17
3P-M-A	Plug	Rc 3/8	71	(51)	25	R 3/8	Hex.21
4P-M-A	Plug	Rc 1/2	149	(62)	28	R 1/2	Hex.27
6P-M-A	Plug	Rc 3/4	295	(75)	36	R 3/4	Hex.35
8P-M-A	Plug	Rc 1	406	(83)	40	R1	Hex.41

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
TSP CUPLA Socket with Ball Valve	10 bar	1/4 inch to 1 inch	One-way shut-off	Water, Hydraulic oil, Air, Gas
ZEROSPILL CUPLA	36 bar	1/4 inch, 3/8 inch, 1/2 inch, 3/4 inch, 1 inch (thread)	Two-way shut-off (Spill Reduction)	Water, Hydraulic oil, Chemicals, Air, Gas
SP CUPLA Type A	75 bar	1/8 inch to 2 inch	Two-way shut-off	Water, Hydraulic oil, Chemicals, Air, Gas, Steam
TSP CUPLA	75 bar	1/8 inch to 2 inch (thread and hose)	Straight through	Water, Hydraulic oil, Chemicals, Air, Gas, Steam

Choose SP CUPLA Type A when a line in the 1.5 to 7.5 MPa {15 to 76 kgf/cm2} range has to shut off on both sides as it is disconnected. TSP CUPLA covers the same pressure range but is straight through and does not shut off, and TSP CUPLA Socket with Ball Valve is one-way shut-off and limited to 1.0 MPa {10 kgf/cm2}. ZEROSPILL CUPLA is also two-way shut-off and additionally reduces spillage, but it stops at 3.5 MPa {35 kgf/cm2}.

Body and seal materials

Body material
Brass
Stainless steel (SUS304)
Steel (Nickel plated)

Seal material	Mark	Working temperature	Remarks
Nitrile rubber (NBR)	-	-20 °C to +80 °C	-
Fluoro rubber (FKM)	-	-20 °C to +180 °C	-
Ethylene-propylene rubber (EPDM)	-	-40 °C to +150 °C	-

Further catalogue data

Note	Value
Working pressure - brass, sizes 1/8 inch, 1/4 inch, 3/8 inch	5.0 MPa {51 kgf/cm2} = 50 bar = 725 PSI
Working pressure - brass, sizes 1/2 inch, 3/4 inch, 1 inch	3.0 MPa {31 kgf/cm2} = 30 bar = 435 PSI
Working pressure - brass, sizes 1 1/4 inch, 1 1/2 inch	2.0 MPa {20 kgf/cm2} = 20 bar = 290 PSI
Working pressure - brass, size 2 inch	1.5 MPa {15 kgf/cm2} = 15 bar = 218 PSI
Working pressure - stainless steel (SUS304) and steel (nickel plated), sizes 1/8 inch, 1/4 inch, 3/8 inch	7.5 MPa {76 kgf/cm2} = 75 bar = 1090 PSI
Working pressure - stainless steel (SUS304) and steel (nickel plated), sizes 1/2 inch, 3/4 inch, 1 inch	4.5 MPa {46 kgf/cm2} = 45 bar = 653 PSI
Working pressure - stainless steel (SUS304) and steel (nickel plated), sizes 1 1/4 inch, 1 1/2 inch	3.0 MPa {31 kgf/cm2} = 30 bar = 435 PSI
Working pressure - stainless steel (SUS304) and steel (nickel plated), size 2 inch	2.0 MPa {20 kgf/cm2} = 20 bar = 290 PSI
Maximum tightening torque - steel	1/8 inch 9 {92}, 1/4 inch 14 {143}, 3/8 inch 22 {224}, 1/2 inch 60 {612}, 3/4 inch 90 {918}, 1 inch 120 {1224}, 1 1/4 inch 260 {2652}, 1 1/2 inch 280 {2856}, 2 inch 500 {5100} Nm {kgf - cm}
Maximum tightening torque - brass	1/8 inch 5 {51}, 1/4 inch 9 {92}, 3/8 inch 12 {122}, 1/2 inch 30 {306}, 3/4 inch 50 {510}, 1 inch 65 {663}, 1 1/4 inch 150 {1530}, 1 1/2 inch 180 {1836}, 2 inch 260 {2652} Nm {kgf - cm}
Maximum tightening torque - stainless steel	1/8 inch 9 {92}, 1/4 inch 14 {143}, 3/8 inch 22 {224}, 1/2 inch 60 {612}, 3/4 inch 90 {918}, 1 inch 120 {1224}, 1 1/4 inch 260 {2652}, 1 1/2 inch 280 {2856}, 2 inch 500 {5100} Nm {kgf - cm}
Minimum cross-sectional area (mm2)	1SP-A 14, 2SP-A 26, 3SP-A 51, 4SP-A 73, 6SP-A 178, 8SP-A 229, 10SP-A 395, 12SP-A 553, 16SP-A 803
Admixture of air on connection (mL)	1SP-A 0.6, 2SP-A 1.1, 3SP-A 2.7, 4SP-A 3.9, 6SP-A 11, 8SP-A 17, 10SP-A 29, 12SP-A 45, 16SP-A 84. May vary depending upon the usage conditions.
Volume of spillage per disconnection (mL)	1SP-A 0.4, 2SP-A 0.8, 3SP-A 2.1, 4SP-A 3.4, 6SP-A 9.5, 8SP-A 15, 10SP-A 29, 12SP-A 45, 16SP-A 84. May vary depending upon the usage conditions.
Flow direction	Fluid flow can be bi-directional when socket and plug are connected.
Accessory	CUPLA ADAPTER for Braided Hose Connection, can be screwed into CUPLA with female threads 3/8 inch, 1/2 inch, 3/4 inch (see page 166).
Accessory	SLEEVE STOPPER for SP CUPLA Type A: sleeve stopper exclusively for SP CUPLA Type A sockets. Attaching the sleeve stopper after connection of socket and plug locks the sleeve of the socket and prevents unexpected disconnection (see page 165).
Related product	SP CUPLA Type A PV Type (made-to-order): SP CUPLA Type A equipped with a residual pressure eliminating valve for connection with residual pressure. The small purge valve is pressed and completes the connection by releasing the residual pressure. Smooth connection even when there is residual pressure when connecting; no residual pressure eliminating operation required on your piping (see page 161).
Flow rate	Flow rate - pressure loss characteristics chart on page 86 for the pairs 1S-A x 1P-A to 16S-A x 16P-A. Test conditions: fluid water, temperature 23 deg C. Chart range 1 to 1000 L/min against 0.001 to 1.0 MPa {0.01 to 10 kgf/cm2} pressure loss.

Interchangeability and size groups

Socket and plug of different sizes cannot be connected. Interchangeable with conventional SP CUPLA in the same size. Can be connected with SP-V CUPLA but take heed of flow rate change.

Safety and application notes

Before use, please be sure to read the Safety Guide described at the end of the catalogue and the Instruction Sheet that comes with the products.
Depending on the temperature of steam / hot water, the heat may damage seal materials.

All technical data on this page is taken from the Nitto Kohki general catalogue Quick Connect Couplings C01en-b, page 85. The complete catalogue is available for download on this page.

What is a Nitto Kohki SP Cupla Type A and what industrial applications require this pneumatic coupling?

The Nitto Kohki SP Cupla Type A is a high-performance pneumatic quick connect coupling engineered for medium pressure applications up to 75 bar in industrial pneumatic and hydraulic systems. These couplings are essential in manufacturing automation, semiconductor fabrication, pharmaceutical processing, and precision machining operations where rapid tool changes and secure fluid connections are critical. The SP-A design enables swift connection and disconnection of pneumatic lines without pressure loss, making it indispensable for production lines requiring frequent equipment reconfiguration and maintenance access.

What are the key technical selection criteria for choosing between different Nitto Kohki SP-A Cupla variants?

Selection of SP-A Cupla variants depends on body material compatibility, seal elastomer chemistry, and port configuration for specific operating conditions up to 75 bar maximum pressure. Stainless steel (SUS) bodies provide superior corrosion resistance for aggressive media, while brass offers cost-effectiveness for standard compressed air applications. Seal material selection between NBR, EPDM, and FKM elastomers determines chemical compatibility, with FKM providing the broadest chemical resistance range and temperature stability. Port sizes available include 10S-A, 12S-A, and 16S-A configurations, with socket (S) and plug (P) connection types for complete system integration.

Which international standards and certifications apply to Nitto Kohki SP Cupla Type A pneumatic couplings?

Nitto Kohki SP Cupla Type A couplings are manufactured to comply with ISO 4414 pneumatic system safety requirements and ISO 5676 quick-acting coupling specifications for interchangeability and performance standards. The stainless steel variants meet food-grade applications under FDA CFR 21.177.2600 regulations when equipped with appropriate seal materials. These couplings are designed for industrial environments requiring IP65 ingress protection ratings and can operate within ATEX Zone 2 classified areas when properly specified with compatible seal compounds and surface treatments for potentially explosive atmospheres.

What are the main differences between SP-A Cupla variants in terms of body materials and seal options?

The SP-A Cupla range offers three primary body materials with distinct performance characteristics for different operating environments up to 75 bar service pressure. Stainless steel (SUS) bodies provide maximum corrosion resistance and cleanability for pharmaceutical, food processing, and chemical applications, while brass bodies offer excellent machinability and thermal conductivity for standard industrial compressed air systems. Carbon steel bodies deliver high strength and cost-effectiveness for general manufacturing applications. Each body material is available with NBR seals for petroleum-based fluids, EPDM seals for water and steam service, or FKM seals for aggressive chemicals and high-temperature applications up to 200°C.

What installation requirements and system compatibility considerations apply to SP-A Cupla connections?

SP-A Cupla installations require threaded connections matching the coupling's port configuration, with proper thread sealant application to maintain system pressure integrity up to 75 bar maximum operating pressure. The socket components mount permanently to equipment or manifolds using NPT or metric threaded connections, while plug components attach to pneumatic tools or flexible hoses for quick connection capability. System compatibility requires matching the coupling's flow coefficient (Cv) to application requirements, ensuring adequate bore diameter for the intended flow rates while maintaining the recommended minimum bend radius for connected flexible hoses. Thread engagement must achieve minimum 4-thread contact for pressure integrity and comply with installation torque specifications provided in the technical documentation.

What safety ratings and operating parameter limits define the SP Cupla Type A performance envelope?

Nitto Kohki SP Cupla Type A couplings operate safely at maximum working pressures up to 75 bar with proof pressure testing conducted at 150% of working pressure per ISO 5676 requirements. Operating temperature ranges vary by seal material, with NBR seals functioning from -20°C to +80°C, EPDM seals rated for -40°C to +150°C service, and FKM seals capable of -15°C to +200°C continuous operation. The couplings achieve IP65 ingress protection when properly mated, preventing dust ingress and protecting against low-pressure water jets. Safety factor calculations incorporate a 4:1 design margin against ultimate tensile strength for all metallic components, ensuring reliable operation under dynamic loading conditions typical in automated manufacturing environments.

What maintenance schedule and inspection requirements ensure reliable SP-A Cupla service life?

SP-A Cupla maintenance requires quarterly visual inspection of coupling bodies for wear, corrosion, or damage, with particular attention to seal groove areas and locking mechanism components operating at pressures up to 75 bar. Seal replacement intervals depend on operating conditions and media compatibility, typically ranging from 12-24 months for NBR seals in standard compressed air service, while FKM seals may achieve 36-month service life in chemical applications. Annual pressure testing at 110% of working pressure verifies coupling integrity and leak-tightness per ISO 5676 maintenance protocols. Expected service life exceeds 100,000 connection cycles under normal operating conditions when proper maintenance schedules are followed and compatible seal materials are selected for the specific application environment.