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Small brass check valve, deep black finish, G1/4 thread

Alphacool

Alphacool 20046 G1/4 Check Valve Deep Black

SKU CH-QK3Y-RW70Z MPN 20046

A G1/4" brass check valve in deep black that prevents reverse flow in custom liquid-cooling loops

  • TypeFittings
  • G1/4" thread fits standard water-cooling loops
  • Brass body resists corrosion in liquid-cooling systems
  • Deep Black chromatised finish prevents colour peeling
  • Check-valve design allows flow in one direction only
  • High-flow inner diameter maximises coolant throughput

G1/4 Check Valve for Liquid Cooling

The Alphacool 20046 is a brass check valve with a G1/4 inch thread and a Deep Black chromatised finish. It allows coolant to flow in one direction only, preventing backflow in custom liquid-cooling loops. The high-flow internal bore keeps restriction low while the durable coating resists peeling. It suits builders who need reliable directional control in a compact fitting.

Thread Standard and Flow Limits

The G1/4 thread is the common standard for PC water-cooling components, so the valve screws into most radiators, blocks and reservoirs without adapters. Because it is a passive mechanical valve, it adds a small cracking pressure that the pump must overcome. Loops with very low pump head or extremely restrictive layouts may see a measurable flow reduction. The valve cannot regulate pressure or prevent leaks from damaged seals.

Replaces Inline Barbs or Rotary Fittings

This valve replaces a standard straight or rotary fitting when the design calls for guaranteed one-way flow, such as drain lines, fill ports or parallel loop branches. The upgrade is worth it when backflow could introduce air bubbles or cause reservoir overflow during maintenance. It is not for builders who need a simple pass-through fitting without any flow restriction or cracking pressure.

Highlights

  • G1/4" thread fits standard water-cooling loops
  • Brass body resists corrosion in liquid-cooling systems
  • Deep Black chromatised finish prevents colour peeling
  • Check-valve design allows flow in one direction only
  • High-flow inner diameter maximises coolant throughput

Specifications

BrandAlphacool
ModelAlphacool G1/4 Check Valve - Black
TypeFittings

Questions about this item

How do I choose the right check valve for my G1/4" loop?

This model 20046 is a G1/4" check valve in Deep Black brass; select it when your loop uses standard G1/4" threads and you want the black finish to match other Alphacool fittings.

What does the G1/4" thread mean once the valve is installed in a custom loop?

The G1/4" thread is the industry-standard fitting size for water-cooling components, so this valve screws directly into any G1/4" port on radiators, blocks, reservoirs or pumps without adapters.

Does the G1/4" interface limit flow or pressure in a high-flow build?

The brass body is machined for a high-flow inner diameter, so the G1/4" connection does not create a bottleneck; the valve simply prevents reverse flow while maintaining the loop's normal flow rate.

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