This New Yorker Boiler Relief Valve is a safety device designed to control or limit the pressure in the system and prevent it from building up and causing potential damage or explosion. The valve has a 3/4 inch inlet and outlet size, which is standard for most residential and commercial applications. It is set to open at a pressure of 50 pounds per square inch (psi), ensuring that the system operates within safe limits. With a British thermal unit (BTU) rating of 950,000, this relief valve can handle high-capacity systems, making it suitable for large-scale operations.