What is required downstream of each PSV when discharged vertically?

When a pressure safety valve (PSV) discharges vertically, having a drip pan elbow is essential to manage any potential liquid that may accumulate at the outlet of the valve. The purpose of the drip pan elbow is to direct any condensation or liquid back to the system or to a safe drain, preventing pooling or the possibility of dangerous overflow situations. This design feature is crucial for ensuring safety and compliance with regulations.

In contrast, while a drain valve, discharge pipe, and pressure gauge are important components in a piping system, they do not specifically address the need to manage the liquid discharge effectively when a PSV discharges vertically. The drip pan elbow is specifically tailored for this scenario, underscoring its necessity in maintaining operational safety and system integrity.