AquaLock 3539R-1004 Reducing Stop Valve 1/2 in CTS x 1/4 in OD Push-to-Connect

The AquaLock 3539R-1004 is a 1/2-inch CTS x 1/4-inch OD plastic reducing straight stop valve from the Watts AquaLock Series 35 push-to-connect fitting line. Engineered for fast, reliable installation, this reducing valve delivers a secure shut-off connection between 1/2-inch CTS supply lines and 1/4-inch OD tubing — with no tools, compression sleeves, clamps, or adhesives required.

Manufactured in off-white polysulfone, a high-performance thermoplastic material built for long-term durability, this valve is designed for years of trouble-free service. A unique O-ring guide feature ensures a zero-leak connection every time. Unlike traditional barb-style fittings, the AquaLock design grips the tubing from the outside, which preserves full interior flow capacity. Once connected, the tubing retains the ability to swivel, making this fitting ideal for vibrating and dynamic plumbing applications.

Key Features:

• Connections: 1/2 in CTS inlet x 1/4 in OD outlet — reducing configuration
• Push-to-connect design — tool-free, snap-on installation
• Zero-leak O-ring guided connection
• Compatible with copper, CPVC, PEX, and CTS-rated pipe
• Suitable for both hot and cold water applications
• Manufactured in off-white polysulfone (high-performance thermoplastic)
• Lead-free construction
• Tubing can swivel after connection for vibration-tolerant installs
• Certified to NSF-61, NSF-14, CSA B137.5, and ASTM F877 standards
• Recognized by the Uniform Plumbing Code and IAPMO

The AquaLock 3539R-1004 is well-suited for residential plumbing, marine, RV, and water treatment applications. Also marketed under the SeaTech brand; Watts has rebranded SeaTech to AquaLock, with part numbers and specifications remaining identical. UPC: 098268299502. Ordering Code: 0959099.