Definition
Dart Valve — A dart valve is a dart-shaped check cartridge dropped or pumped down the drill string to seat in a landing sub, where it converts the string into a one-way, downward-flow barrier during well-control operations.
Also known as: dart valve, drop dart, pump-down dart
What a dart valve does
A dart valve is the deployable element of a drop-in check-valve system. It has a streamlined, dart-like body carrying a spring-loaded check that is released into the open string and carried down by circulation to a preinstalled landing sub. Once landed and locked, it seals against upward flow while still allowing mud to be pumped downward, giving the crew a string barrier without breaking out the pipe.
Dart valves are used when a kick must be contained through the pipe bore and a surface valve cannot be stabbed quickly, or as an added contingency barrier during circulation. Some designs are retrievable so the string can be reopened after the well is secured.
How it works with the landing sub
The dart is sized to seat and lock in a specific landing sub. Correct matching of the dart to the sub bore and profile is essential so it lands, seals and holds the expected differential pressure. The sub is made up in the string at a planned depth before the dart is dropped.
Why it matters for rentals
Dart valves and their landing subs are pressure-critical, matched components that require current certification and pressure testing. Rental sets should suit your string bore and working pressure. See our pressure control equipment or contact us with your specs.