What lurks beneath the surface? What is underneath, where eyes cannot see? Is it something valuable? Is it something old? Is it some treasure or something frightening to behold? These are common questions for miners, deep-sea oceanographers, or even a young child staring into the murky water, but this is an article on boiler steam stop valves. What exactly do these questions have to do with the subject matter? Let’s find out.
Located at the steam outlet of the boiler, the steam stop valve provides a means of isolation. For multiple boiler installations, two stop valves are required. Typically, one of the two valves is a gate valve, and the other is commonly a stop-check valve. In lower pressure/temperature applications, a solid wedge gate valve can be used, while a flexible wedge style is typically employed when ANSI CL600 – CL900 valve ratings are required. Above Class 900, the most common design chosen is the parallel disc or parallel slide gate valve.