Petroleum refineries and several other processing industries have high-temperature flows. Valves used for throttling and on/off control must be made of materials to withstand the high temperatures.
In a Hydrocarbon Processing article, Using ball valves in high-temperature applications, Emerson’s Jason Jablonski and Wade Helfer share recommendations for manufacturers and producers to use in specifying and purchasing suitable valves.
For their article, high temperature is any process fluid greater than 400 degF/204 degC.
They open highlighting some of the high temperature applications for the ball valves:
- Hydrocracker feed: 650°F (343°C)
- Gas plant debutanizer bottom product: 650°F (343°C)
- Hydrotreater: 750°F (399°C)
- Catalyst in hydrocracking: 950°F (510°C)
- Coker crude oil bottoms, furnace feed, coke slurry, drum switching, blowdown and overhead vapor: 970°F (521°C)
- CCR and FCCU catalyst handling, flue gas and fractionator bottoms: up to 1,400°F (760°C)
Power plant steam:
…may also require dozens of condensate drain valves and vents with temperatures exceeding 1,000°F (538°C).
Valve drivetrains are one source of potential failure, since:
…torque may increase up to two times compared to what is experienced at ambient temperature, thereby making actuator sizing critical.
Jason and Wade note the careful attention the valve trim requires. Beyond fluid compatibility:
…they must also be capable of withstanding high stresses…they should be made from corrosion-resistant material that maintains high yield strength and torsional stiffness at elevated temperatures, such as Inconel 718, 17-4 stainless steel or Nitronic 50.
Tight shutoff is another big consideration since metal-to-metal seals are required for these high temperature applications. They also share several ways to harden the surfaces of trim components.
Suitability for the application requires an understanding of the coefficients of thermal expansion for the valve materials. Also the duty whether used in a throttling or on/off application due to the change in heat profile.
Read the article for more on stem seal considerations, packing problems, body gasket considerations, and relevant industry standards. Working with a trusted supplier to test and verify performance is important to select the right valves with the right materials, actuator and accessories for their intended us.
Visit the Fisher Z500 Severe Service Ball Valve page on Emerson.com for more on the specifications on a potential solution for your high temperature applications. You can also connect and interact with other valve experts in the Valves, Actuators & Regulators group in the Emerson Exchange 365 community.