Fitting kit Alphacool 17377 — brass, black, height 16 mm, diameter 21 mm for liquid cooling

Alphacool 17377 is a brass fitting kit with a black finish, designed for custom liquid cooling loops in PCs. The connector has a height of 16 mm and an outer diameter of 21 mm and is intended to connect and seal coolant tubing, fittings and adaptors. Manufactured as part of Alphacool’s Eiszapfen Connector Series, this fitting is engineered for high flow, secure sealing and durable surface coating to withstand regular use in water-cooling systems.

Advantages

The brass construction provides mechanical strength and corrosion resistance while the special coating process bonds the black finish to the surface to reduce chipping and peeling. The Eiszapfen series design includes slanted nut edges that press the O-ring firmly against hard tubing for improved sealing and transport safety. Multiple O-ring colour options are included in the shipment, and the fittings are compatible with the UV-light reactive O-rings available for visual customization.

Suitable for

• Building or repairing custom PC water-cooling loops
• Connecting hard tubing, adaptors and other fittings in cooling circuits
• High-flow cooling applications requiring secure, low-leak connections

Key specifications

• Material: brass body
• Finish: matte black coated surface
• Height: 16 mm
• Outer diameter: 21 mm
• Series: Eiszapfen Connector Series
• Sealing: O-ring based sealing for hard tubing

How to use

Install the fitting by sliding it onto the prepared hard tubing or by connecting it to the corresponding adaptor or port in the cooling loop. Ensure the appropriate O-ring is seated correctly in the nut groove and that the tubing end is pushed fully against the fitting seat. Tighten the nut with hand force and, if required, a light tool-assisted turn to achieve a secure seal; avoid over-tightening to prevent damage to the O-ring or tubing. Verify alignment and tighten progressively while checking for even contact with the O-ring.

Recommendations

Before final system fill, perform a pressure or leak test with distilled water or a compatible test fluid and run the pump for several hours to confirm there are no leaks. Use O-rings that match the tubing diameter and consider the supplied coloured O-rings or UV-reactive variants for visual identification. Periodically inspect fittings and O-rings during maintenance and replace O-rings showing wear or deformation to maintain leak-free operation.