(June 5, 2020, 2:49 PM EDT) -- HOUSTON — A group of affiliated companies that make fluid control devices for the hydraulic fracturing industry on May 27 sued a company that sells those same pieces of equipment, alleging that it violated federal law when it engaged in “inequitable conduct” to obtain a patent for something that was the property of the plaintiff (Vulcan Industrial Holdings LLC, et al. v. Kerr Machine Co., et al., No. 20-1852, S.D. Texas)....