Does the Quick coupling plug with hose end, NITTO KOHKI HI CUPLA, stainless steel AISI 304 require a specific flow direction from socket to plug for safe operation?

Yes. The Quick coupling plug with hose end, NITTO KOHKI HI CUPLA, stainless steel AISI 304 requires the medium to flow from the socket to the plug for safe and proper operation. It is a plug without a valve, designed specifically for water installations; correct flow direction ensures the coupling functions as intended, maintains vibration resistance and durability, and meets the specified working pressure (15 bar) and flow rates (4000 l/min 1â³; 3200 l/min 3/4â³; 2600 l/min 1/2â³; 1600 l/min 3/8â³; 1000 l/min 1/4â³ at 5 bar). Operating it in the opposite direction may compromise sealing and safety.

Can the Quick coupling plug with hose end, NITTO KOHKI HI CUPLA, stainless steel AISI 304 be used if fluid flows from plug to socket?

No - Quick coupling plug with hose end, NITTO KOHKI HI CUPLA, stainless steel AISI 304 cannot be used if fluid flows from plug to socket. The product description specifies it is designed for water installations and that the medium must flow from the socket to the plug; the plug is without a valve and requires flow in that specified direction. Using it with flow from plug to socket risks leakage, malfunction, or failure.

Quick coupling plug with hose end, NITTO KOHKI HI CUPLA, stainless steel AISI 304

Q: Is it safe to use the Quick coupling plug with hose end, NITTO KOHKI HI CUPLA, stainless steel AISI 304 if fluid flows from plug to socket?

No. it is not safe. The Quick coupling plug with hose end, NITTO KOHKI HI CUPLA, stainless steel AISI 304 (plug without valve) is specified and designed for medium flow from the socket to the plug. Using it with fluid flowing from the plug to the socket can bypass intended sealing and safety features, leading to leaks, loss of connection integrity, or component damage. Although the material (AISI 304) and pressure/flow ratings (up to 15 bar, listed flow rates at 5 bar) indicate good mechanical capacity, the explicit note that the medium must flow from the socket to the plug is a functional requirement. violating it risks improper operation and potential safety hazards. Use the coupling only in the direction specified or select a version with a valve or a plug/sockel pair rated for bidirectional flow.

All products, General-purpose low-pressure quick couplings/

Additional information

Material	SS – stainless steel

Nitto Kohki HI CUPLA series plug without valve with hose end, featuring excellent durability and vibration resistance. Designed for water installations. Material: AISI 304 steel. Working pressure: 15 bar. Flow rate: 4000 l/min (1″), 3200 l/min (3/4″), 2600 l/min (1/2″), 1600 l/min (3/8″), 1000 l/min (1/4″) at a pressure of 5 bar. Note: the medium must flow from the socket to the plug.

List of product variants

Article number	Product variant name	Nominal inner diameter	Working pressure [bar]
NK-20PH-SS	HI CUPLA quick coupling plug, for 1/4" hose, AISI 304	-	15
NK-30PH-SS	HI CUPLA quick coupling plug, for 3/8" hose, AISI 304	-	15
NK-400PH-SS	HI CUPLA quick coupling plug, for 1/2" hose, AISI 304	-	15
NK-40PH-SS	HI CUPLA quick coupling plug, for 1/2" hose, AISI 304	-	15
NK-600PH-SS	HI CUPLA quick coupling plug, for 3/4" hose, AISI 304	-	15
NK-800PH-SS	HI CUPLA quick coupling plug, for 1" hose, AISI 304	-	15

Nitto Kohki HI CUPLA series plug without valve with hose end, featuring excellent durability and vibration resistance. Designed for water installations. Material: AISI 304 steel. Working pressure: 15 bar. Flow rate: 4000 l/min (1″), 3200 l/min (3/4″), 2600 l/min (1/2″), 1600 l/min (3/8″), 1000 l/min (1/4″) at a pressure of 5 bar. Note: the medium must flow from the socket to the plug.