NASA's Marshall Space Flight Center has developed a device and method for blocking the flow of fluid from an open pipe. The device plugs, controls, and meters the flow of gases and liquids. Anchored with friction fittings, spikes, or explosively activated fasteners, the device is well-suited for harsh environments and high fluid velocities and pressures. With the addition of instrumentation, it can also be used as a variable-area flow metering valve that can be set based upon flow conditions. With robotic additions, it can be configured to crawl into a pipe and then anchor and activate itself to block or control fluid flow.
The device incorporates a metallic, variable-area, cone-shaped mechanism to restrict the cross-sectional area of a pipe to throttle and control gas and liquid flow. The pointed shape allows easy insertion into a flowing pipe with minimal resistance. The device is anchored within the pipe using compression, lead screws, or pyrotechnic mechanisms when activated remotely. Actuators are used to mechanically change the device shape, which stops or controls pipe flow; with appropriate robotics, activation can be performed remotely. With proper pipe framing, nearly 100% flow blockage is possible.
For the oil industry, the device can reduce the amount of escaping oil from a broken pipe while relief wells are drilled. The device can then be removed or used as a valve to measure the amount of flow from inside the pipe, much like a control valve. In the fluid handling industry, the device can be used with additional instrumentation as a variable-area flow meter that can be set based upon flow conditions to enhance flow metering accuracy, control pressure losses, or control flow in a closed-loop feedback.