A manifold body includes at least first and second valve body segments each comprising an upper perimeter wall portion defining a valve cavity and a lower base portion defining one or more flow ports, a unified leak test port, a first branch leak test passage extending from the unified leak test port to an outer peripheral portion of the valve cavity of the first valve body segment, radially outward of an outer seal surface in the valve cavity, and a second branch leak test passage extending from the unified leak test port to an outer peripheral portion of the valve cavity of the second valve body segment, radially outward of an outer seal surface in the valve cavity.

An assembly is provided for performing start-up testing on a fluid flow control device. The assembly includes a retainer adapted to be disposed in a valve body of the fluid flow control device, and a sealing assembly coupled to a portion of the retainer and adapted to be disposed adjacent a valve seat of the fluid flow control device. The sealing assembly includes one or more sealing elements configured to provide a seal during start-up testing at a service temperature of between approximately 325 degrees Fahrenheit and approximately 1250 degrees Fahrenheit.

A vacuum relief valve for a railroad tank car and methods for using the same to test the vacuum relief valve for leaks without requiring removal of the valve from the railroad tank car are described herein. According to one aspect of the invention, a vacuum relief valve described herein may be inspected for leaks without removing the vacuum relief valve from the railroad tank car by using two or more access openings located on the body of the vacuum relief valve. According to another aspect of the invention, a vacuum relief valve described herein may be inspected for leaks without removing the vacuum relief valve from the railroad tank car by using an opening to an interior cavity of the valve body that is revealed by rotating a cover from a closed position to an open position.

Apparatus and methods detect blind leaks in a fire suppression system. A valve assembly comprises an absorption spectrometer and a controller, in which the absorption spectrometer include a light source and a light sensor. A first generated light is emitted from the light source. A first measured light corresponding to the first generated light is detected at the light sensor at a first receiving time. A second generated light is emitted from the light source. A second measured light corresponding to the second generated light is detected at the light sensor at a second receiving time different from the first receiving time. A concentration of an extinguishing agent between the light source and the light sensor is determined based on a difference between a first measurement of the first measured light and a second measurement of the second measured light.

Techniques for detecting a high gas pressure situation within a gas delivery system (e.g., for natural gas delivery to homes and businesses) are described. In one example, a device measures gas pressure. If a pressure over a threshold value is detected, a nearby device is messaged. The nearby device either confirms the over-pressure condition or indicates it may be more localized. If the condition is present within an area of the gas delivery system and/or within a group of devices within the gas delivery system, protective measures may be taken, such as closing valves providing gas to a number of service sites.