Is the QC-LOK® Quick Connector Plug Cap with Cord, Type QC4/QC6 suitable for use under pressure or only for protection when disconnected?

The QC-LOK® Quick Connector Plug Cap with Cord, Type QC4/QC6 is intended only for protection when the coupling is disconnected, not for use under pressure. It protects plugs and sockets from dirt, dust, and mechanical damage, but is not designed to transfer or contain pressure. Made of AISI 316 stainless steel with a tether and rated for -26°C to +204°C, it ensures durable, corrosion-resistant protection and secure handling, extending component life in demanding environments.

Can the QC-LOK® Quick Connector Plug Cap with Cord, Type QC4/QC6 be used in corrosive or marine environments without additional protective coatings?

Yes. The QC-LOK® Quick Connector Plug Cap with Cord, Type QC4/QC6 can be used in corrosive and marine environments without additional protective coatings in most cases. It is manufactured from AISI 316 stainless steel, which offers excellent corrosion resistance—particularly against chlorides and saltwater—and is commonly specified for marine and corrosive-service applications. Its durable construction, resistance to wear, and wide operating temperature range (-26°C to +204°C) further support reliable performance in demanding environments. Caveats: for extremely aggressive chemistries, prolonged immersion in highly concentrated chloride solutions, or unusually harsh marine conditions (e.g., tidal zones with heavy biofouling or stray-current corrosion), additional protective measures or a site-specific corrosion assessment may be advisable to ensure long-term performance.

QC-LOK® Quick Connector Plug Cap with Cord, Type QC4/QC6

All products, Precision threaded fasteners/

Additional information

Material	SS – stainless steel

The plug cap for quick couplings QC4 and QC6, manufactured in compliance with Standard Instrumentation requirements, offers reliable protection for your equipment when the connection is disengaged. Designed for sizes 1/4″ and 3/8″, it is equipped with a practical tether to ensure secure handling and prevent misplacement. Made from durable AISI 316 stainless steel, the cap provides exceptional resistance to corrosion and wear, guaranteeing long-lasting performance even in demanding environments. While not intended for pressure transfer, it effectively safeguards plugs and sockets from dirt, dust, and mechanical damage, maintaining system integrity and extending the service life of your components. With an impressive operating temperature range from -26°C to +204°C, this cap ensures dependable functionality across a wide variety of applications, making it an essential accessory for maintaining cleanliness, safety, and efficiency in your operations.

List of product variants

Article number	Product variant name	Nominal inner diameter	Working pressure [bar]	Enquiry
HM-QC4-SP-SS	QC4 plug blind cap, SS	-	-
HM-QC6-SP-SS	QC6 plug blind cap, SS	-	-

The plug cap for quick couplings QC4 and QC6, manufactured in compliance with Standard Instrumentation requirements, offers reliable protection for your equipment when the connection is disengaged. Designed for sizes 1/4″ and 3/8″, it is equipped with a practical tether to ensure secure handling and prevent misplacement. Made from durable AISI 316 stainless steel, the cap provides exceptional resistance to corrosion and wear, guaranteeing long-lasting performance even in demanding environments. While not intended for pressure transfer, it effectively safeguards plugs and sockets from dirt, dust, and mechanical damage, maintaining system integrity and extending the service life of your components. With an impressive operating temperature range from -26°C to +204°C, this cap ensures dependable functionality across a wide variety of applications, making it an essential accessory for maintaining cleanliness, safety, and efficiency in your operations.