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Sloan Valve Company vs. Zurn Industries

Case Summary: 10-cv-204

This case began in 2010 when Sloan Valve Co. (Sloan) filed a complaint against Zurn Industries (Zurn) alleging that Zurn had infringed upon a patent Sloan has. The patent is for a manual plumbing system that permits a user to flush one amount of water for solid waste and a significantly reduced amount of water for liquid waste. Sloan is asking for injunctive relief to prevent Zurn from continuing to sell a similar system and monetary damages. Zurn is asking the court to declare Sloan’s patent to be unenforceable. A jury trial was requested.

This video is of a “Markman hearing” and includes the testimony of expert witnesses, presentation of exhibits, and argument of counsel. A Markman hearing is a pretrial hearing during which the judge examines evidence to determine the meaning of key words used in the patent claim. It is also known as a "Claim Construction Hearing". Holding a Markman hearing has been common practice since the U.S. Supreme Court found that the language of a patent is a matter of law for a judge to decide, not a matter of fact for a jury to decide. In the United States, juries determine the facts, but judges determine the law. The evidence considered in a Markman hearing falls into two categories: intrinsic and extrinsic. Intrinsic evidence consists of the patent documentation and any evidence presented to obtain, amend, or object to the patent (aka the prosecution history). Extrinsic evidence is testimony, expert opinion, or other unwritten sources. Extrinsic evidence may not contradict intrinsic evidence. The court has not yet ruled in favor of either party in this hearing.

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Case-related documents, including those referenced above, are available via the Public Access to Court Electronic Records (PACER) service. For more information, visit