A ball valve consists of a floating ball with a ho...MORE >>
When you talk about steam, the temperature and pressure […]
When you talk about steam, the temperature and pressure plays a very important role in the choice of valves apart from the application.
The globe valves are one of the best valves for regulating/ throttling purpose in comparison to other valves where the steam usually just breaks through and tears the valve apart.
The ball valves are probably the best valves for isolation purpose though. Since their sealing surface hardly comes in contact with the flow of steam. That being the major difference.
When talk about temperature and pressure playing an important role, the higher the temperature and pressure ( ASME Class ) the worse the steam gets and affects the valve. What I mean to say is, a globe valve could last for years in a service where the temperature and pressure are less. Whereas the same globe valve would miserably fail as we go higher on the P and T curve.
Cost definitely comes into place where globe valves are cheaper and can be repaired easily as compared to ball valves. The end users tend to continuously repair or replace the cheap globe valves as they have a lower initial cost.