The Reliance 7 Bar TPR15 Pressure Temperature Relief Valve with a 200mm probe is designed for use in hydronic (hot water) heating systems, specifically in indoor storage tanks. Made with brass tank lining material, this model (Alpha) features a temperature pressure relief valve function. Its medium water heater profile and green colour make it a reliable and visually appealing addition to any heating system. With its dependable brand reputation and specific design features, this pressure relief valve offers peace of mind and efficiency in regulating water temperature and pressure.