What is the minimum pressure above which the exhaust side of a steam turbine may be protected by a safety valve or rupture disc?

The minimum pressure above which the exhaust side of a steam turbine may be safely protected by a safety valve or rupture disc is 15 psig. This standard is in place because safety devices are designed to help prevent overpressure situations, effectively protecting both the equipment and personnel.

In steam turbine operations, the exhaust side experiences a variety of pressure changes and requires careful monitoring. By establishing a minimum of 15 psig, regulators ensure that there's a sufficient margin for safety mechanisms to function properly without risking premature activation due to minor fluctuations in pressure.

This choice aligns with industry standards and regulations that aim to protect systems from unexpected failures and maintain safe operational conditions. Understanding this threshold is crucial for those working with steam turbines, as it helps in the selection and installation of appropriate safety devices that will operate effectively without impeding normal system performance.