valves quix

• After an adjustment of the packing gland on a valve that had a minor leak, the operator attempts to operate the valve but finds that the valve is stuck.  What is the most probable cause? The operator over-tightened the packing, causing the stem to bind.
• If a discharge valve is opened to the atmosphere, what will happen to the pressure on the upstream side of the valve? decrease, and the pressure on the downstream side will remain the same.
• When comparing the application of a globe and gate valve for the same process, which of the following statements is true? The gate valve has a lower pressure drop when fully open and is the poorer choice for throttling operation.
• Which of the following types of similarly sized valves requires the most manual valve stem rotation to move from fully open to fully closed? (Assume that each valve has a non-rising stem.) Gate
• If you open a discharge valve to the atmosphere, what will happen to the pressure on the upstream side of the valve? The pressure will decrease on the upstream side but will remain the same on the downstream side.
• What type of valve has an operating mechanism that moves a wedge across the passage of flow to close the valve? gate valve
• An outside stem and yoke (OS&Y) valve offers no resistance to the flow of steam when open. True
• The purpose of backseating a manual valve in an operating system is to: Isolate system pressure from the packing and stuffing box to minimize packing leakage.