AquaLock 3515-10 1/2 in. CTS Push-to-Connect Plastic Union Connector Coupling

The AquaLock 3515-10 is a 1/2-inch CTS (Copper Tube Size) push-to-connect plastic union connector coupling designed for fast, reliable, and tool-free plumbing connections. Built from off-white polysulfone — a high-performance thermoplastic — this lead-free fitting delivers years of trouble-free service in both residential and marine water systems.

Simply push the tubing into the fitting for an instant, secure connection. No tools, tube inserts, or thread sealant are required, making this coupling ideal for new installations, repairs, and retrofits. The unique O-ring guide ensures a zero-leak seal every time, and the stainless steel gripping teeth in the collet lock onto tubing firmly and resist corrosion across all compatible materials.

Key Features:

• 1/2 in. CTS x 1/2 in. CTS straight union connector coupling
• Tool-free push-to-connect installation and removal
• Compatible with copper, CPVC, PEX (LDPE, MDPE, HDPE), and CTS-rated pipe
• Unique O-ring guide provides a zero-leak connection
• Joins tubing on the outside, maximizing flow capacity over barb-style fittings
• Rotates under full pressure — ideal for vibrating and dynamic applications
• Stainless steel gripping teeth for corrosion-resistant, multi-material compatibility
• Rated for hot and cold water applications, including behind-the-wall installations
• Pressure ratings: 250 PSI at 75°F (17.3 Bar at 24°C) / 100 PSI at 180°F (6.8 Bar at 82°C)
• Lead-free construction; approved for potable water use
• Backed by a 25-year limited warranty

Certifications & Approvals: FDA, ANSI/NSF-61, NSF-14, CSA B137.5, ASTM F877, NSF-UP, IAPMO ASSE 1061-2006, UPC

Alternate Part Numbers: 003515-10, 013515-10 | Also sold under the SeaTech brand (rebranded to Watts AquaLock; part numbers and specifications unchanged).

The AquaLock 3515-10 is the go-to choice for plumbers, RV technicians, marine installers, and DIYers who need a dependable, reusable coupling that installs in seconds and performs for decades.