A pressure relief valve, PRV, comprising: a first housing part comprising first major and minor surfaces and a first deformed corner at an intersection of the first major and minor surfaces; and a second housing part comprising second major and minor surfaces and a second deformed corner at an intersection of the second major and minor surfaces, the first and second housing parts being disposed with the first and second minor surfaces facing oppositely at a distance to define a metering hole, a sealing ball which is elastically biased toward the metering hole; the first and second deformed corners having been deformed by a coining ball to cooperatively form a coined seat at the metering hole for seating and re-seating the sealing ball, and the first and second deformed corners having respective radii of curvatures resulting from deformation which are larger than that of the sealing ball; wherein: at the first housing part, the coined seat comprises a first curved edge and first corners at opposite ends of the first curved edge, and at the second housing part, the coined seat comprises a second curved edge and second corners at opposite ends of the second curved edge; and the first corners comprise a first major surface corner which protrudes upwardly from a plane of the first major surface and a first minor surface corner which protrudes inwardly from a plane of the first minor surface, and the second corners comprise a second major surface corner which protrudes upwardly from a plane of the second major surface and a second minor surface corner which protrudes inwardly from a plane of the second minor surface; and the first and second minor surface corners are disposed at the metering hole to define a sealing hole having a smaller diameter than the metering hole. a first housing part comprising first major and minor surfaces and a first deformed corner at an intersection of the first major and minor surfaces; and a second housing part comprising second major and minor surfaces and a second deformed corner at an intersection of the second major and minor surfaces, the first and second housing parts being disposed with the first and second minor surfaces facing oppositely at a distance to define a metering hole, a sealing ball which is elastically biased toward the metering hole; the first and second deformed corners having been deformed by a coining ball to cooperatively form a coined seat at the metering hole for seating and re-seating the sealing ball, and the first and second deformed corners having respective radii of curvatures resulting from deformation which are larger than that of the sealing ball; wherein: at the first housing part, the coined seat comprises a first curved edge and first corners at opposite ends of the first curved edge, and at the second housing part, the coined seat comprises a second curved edge and second corners at opposite ends of the second curved edge; and the first corners comprise a first major surface corner which protrudes upwardly from a plane of the first major surface and a first minor surface corner which protrudes inwardly from a plane of the first minor surface, and the second corners comprise a second major surface corner which protrudes upwardly from a plane of the second major surface and a second minor surface corner which protrudes inwardly from a plane of the second minor surface; and the first and second minor surface corners are disposed at the metering hole to define a sealing hole having a smaller diameter than the metering hole. at the first housing part, the coined seat comprises a first curved edge and first corners at opposite ends of the first curved edge, and at the second housing part, the coined seat comprises a second curved edge and second corners at opposite ends of the second curved edge; and the first corners comprise a first major surface corner which protrudes upwardly from a plane of the first major surface and a first minor surface corner which protrudes inwardly from a plane of the first minor surface, and the second corners comprise a second major surface corner which protrudes upwardly from a plane of the second major surface and a second minor surface corner which protrudes inwardly from a plane of the second minor surface; and the first and second minor surface corners are disposed at the metering hole to define a sealing hole having a smaller diameter than the metering hole.