John Guest Quick Connect Inline Shut-Off Valve - 3/8in QC

3/8in QC Inline Shut-Off Valve — Tool-Free Flow Control

This John Guest-format 3/8in Quick Connect Inline Shut-Off Valve gives you instant, tool-free flow control anywhere in a water purification or hydroponic irrigation line. A simple quarter-turn ball valve snaps into 3/8in quick connect (QC) tubing without fittings, clamps, or thread tape, making it easy to isolate sections of a system for maintenance, filter changes, or reconfiguration.

Key Features & Benefits

• Quick Connect Installation: Pushes directly onto 3/8in QC tubing; no tools, thread sealant, or additional fittings required.
• Ball Valve Design: Quarter-turn operation delivers positive on/off shutoff with minimal effort and reliable leak-free sealing.
• Inline Configuration: Mounts anywhere along a water line to isolate components, divert flow, or simplify system servicing.
• Water-Purification-Grade Materials: Suited to RO permeate and feed water lines used in indoor growing and water purification.
• Compact Form Factor: Low-profile body fits in tight equipment bays, filter housings, and under-bench plumbing runs.

Who Should Use This

Home and commercial growers running Hydro-Logic water purification systems, or any hydroponic operator who wants simple shutoff capability at key points in a QC water line.

Compatibility

Designed for 3/8in quick connect (QC) tubing. Compatible with Hydro-Logic Stealth-RO, Evolution-RO, and similar water purification systems using the same tubing size.

About Hydro-Logic

Hydro-Logic Purification Systems is a Hawthorne Gardening Company brand, now under Vireo Growth, best known for reverse osmosis systems and pre-filters such as Stealth-RO, Evolution-RO, smallBoy, and TALLBoy. Quick-connect (QC) push-fit fittings in the John Guest format are a widely used industry standard for water-purification plumbing, and Hydro-Logic offers this line of replacement and accessory QC fittings for use with its own water purification systems and other equipment built to the same QC standard.

Frequently Asked Questions

Do I need any tools or thread tape to install this valve?

No — it pushes directly onto 3/8in QC tubing. No tools, thread tape, or additional fittings are required.

Can I use this valve with non-Hydro-Logic systems?

Yes, as long as your tubing uses 3/8in quick connect fittings, this valve will function correctly regardless of the system brand. It is a universal fitting size, not a proprietary connector.

Is this valve suitable for use with filtered or RO water?

Yes — it is designed for use in water purification lines, including RO permeate and pre-filter feed water. The ball valve seal holds up well under the pressures typical of these lines.

How do I know if the valve is open or closed?

The ball valve handle aligns with the flow direction when open and sits perpendicular to the line when closed, giving a clear visual indicator. A quarter turn is all it takes to switch between the two positions.