BRASS FLARE DEAD NUTS

Product Description

In the HVAC and high-pressure plumbing industry, Brass Flare Dead Nuts (also known as Flare Caps or Blind Flare Nuts) are used to permanently or temporarily seal off an open flare fitting. Unlike a standard flare nut which has a hole for tubing to pass through, a "dead" nut is solid at one end.

1. Function and Utility

A flare dead nut acts as a structural plug. It is used in three primary scenarios:

• System Isolation: To seal off a port on a manifold or a service valve that is not currently in use.

• Leak Testing: To cap off a section of a line set so it can be pressurized with nitrogen to check for leaks.

• Shipping/Protection: To protect the precision-machined threads and flare seat of a component (like a split AC valve) during transport, preventing debris or moisture from entering.

• Key Technical Specifications

  • Material: High-tensile Forged Brass (typically CA360 or CA377). Forging is essential here because a "dead" nut must withstand the full static pressure of the system against its solid base.

  • Thread Type: Standard UNF (Fine Thread), matched to the flare size (e.g., 1/4", 3/8", 1/2" SAE Flare).

  • Pressure Rating: Identical to standard flare fittings, usually rated up to 600700 PSI for HVAC-R applications.