The 840 series cage-guided valve is specially designed using recent advances in control valve technology. It is used to control a wide variety of relatively clean liquids and gases at high pressure differentials. Configured with either flow-to-open or flowto-close trims, the valve is well suited for steam, gas or liquids, where flow-to-close is typically used for liquid service, and flow-toopen for steam and gas. The design of the 840H (drilled-hole-cage) valve is primarily used for severe service applications requiring anti-cavitation or low-noise trim. In most cases, high pressure drop in process conditions may cause erosion, noise or vibration, which can affect process control. The 840H is a good solution to this severe service application.