Sealed Valve to Prevent Negative Pressures in Pipes

Technology #16816

Questions about this technology? Ask a Technology Manager

Download Printable PDF

Image Gallery
Sealed Valve to Prevent Negative Pressures in Pipes 1Sealed Valve to Prevent Negative Pressures in Pipes 2Sealed Valve to Prevent Negative Pressures in Pipes 3Sealed Valve to Prevent Negative Pressures in Pipes 4
Professor Alexander Slocum
Department of Mechanical Engineering, MIT
External Link (
David Taylor
Department of Mechanical Engineering, MIT
Managed By
Christopher Noble
MIT Technology Licensing Officer - Clean and Renewable Energy
Patent Protection

Auto-throttle Valves for Residential Water Supply Systems

PCT Patent Application WO 2015-100502


The technology is applicable to piping systems to maintain a positive or neutral pressure within the main system.

Problem Addressed

Pressure in piping systems can become lower than ambient atmospheric pressure when too much fluid is drawn at a connection, such as with a booster pump.  This negative pressure increases contamination risks in the main system and reduces flow rates in the other pipe connections.  Such problems are particularly evident in municipal water supplies where many household booster pumps are illegally connected directly to the main line and the total available water is limited.  Over-pumping in one household can create negative pressure within the system that can pull in contaminates from the surroundings and prevent other households from receiving any water.  This technology is a tamper-resistant regulation valve that cuts off flow to a connection when the local pressure becomes negative, preventing system-wide negative pressures and maintaining flow rates at the other connections.


The valve in this technology primarily consists of flexible tubing that collapses when the fluid pressure inside the pipe becomes less than ambient atmospheric pressure.  Internal inserts stabilize the tubing and reduces fluttering while a wire mesh adds mechanical strength and prevents ballooning.  The flexible tubing does not allow contact between the fluid within the pipes and the surrounding environment, which protects the system from contamination and, if the system is carrying a hazardous material, preventing toxic spills into the environment.  The valve is enclosed within a larger pipe to prevent tampering that could allow negative pressures into the system.  The enclosure also contains any leaks if the flexible tubing becomes damaged.


  • Low cost
  • Tamper resistant
  • Prevents negative pressures in piping systems
  • Fully enclosed and does not allow contact between fluid in the pipes and the environment