Urea letdown valve from Flowserve Corp. is designed to tolerate the high pressure drops and crystallization associated with the letdown process in urea production.
Urea letdown valve from Flowserve Corp. tolerates the high pressure drops and crystallization associated with the letdown process in urea production.
Urea letdown valve from Flowserve Corp . is designed to tolerate the high pressure drops and crystallization associated with the letdown process in urea production. Valve is robust and rugged with double top-stem guiding, single-point throttling, a single-piece plug, and a clean and streamlined exit. Design is said to minimize vibration, noise, sticking, and plugging common to valves not specifically made to work in urea letdown.
Urea is a common chemical reactant and precursor used in the production of other chemicals and materials, including fertilizers, resins, plastics, and paper. Produced at high temperatures and pressures, it is highly corrosive and erosive. The urea letdown process happens near the end of the production cycle, where pressure is reduced to a more easily handled state. Typical urea production conditions include an inlet pressure of 3,500 psig, an outlet pressure of 300 psig, an operating temperature of 350 °F, and a flow rate of 8 million scfh. A 4-in ANSI Class 2500 valve would be typical for this process.
Valve is made of 316 stainless steel and features a specially shaped Venturi seat ring, sweep-angle design, advanced velocity control, straight-shot exit, and an oversized gallery. The elements reportedly help mitigate the erosive effects of the continuous, high-velocity flow of urea, which may also contain entrained particulates. It is available in 1-4-in. sizes and comes standard with a Flowserve VL cylinder actuator. Valve is compatible with nearly any four-way digital or analog positioner.
—Jeanine Katzel, senior editor, Control Engineering, [email protected]
