Instrument switch valve
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What is the difference between HV and XV?
http://bbs.hcbbs.com/thread-854080-1-1.html:lol
hv: Manual control valve, capable of only controlling the valve position. There is no other variable xv: it is generally a solenoid valve with only two states, on and off. It is generally hung at chain locations
These two aren’t usually distinguished that carefully these days.
HV is a manual control valve, and XV is a interlock valve.
HV/XV: HV is a manual switch and there’s no problem with it; X actually doesn’t mean anything – it’s just the initial letter added before V. I believe these two ways of expression will not appear simultaneously in the design of a single set of equipment; they differ depending on the design unit, and may appear together only at different times of design (modification) for the same set of equipment.
HV has control valves and isolation valves. Generally, it has no control features; it is only operated manually from a distance. XV generally only has a shut-off valve. And there is usually interlocking.
Both of these are automatic valves; manual valves are not labeled in this way. HV refers to the remote control valve. What he means is that the control room issues commands, that is, the operator gives instructions and the valves move; it’s not automatic control based on a feedback loop. It moves as much as the valve position allows; it is set manually, not determined by circuit interlocks. XV switch valve. Ensure that the valve is opened or closed to the full position. Commands can be given manually, or via interlock circuits. Generally, there are only an open position and a closed position.
It means it’s determined by the design. Standards are also just recommendations. Common (*usual): HV is a manual valve. Sometimes, in chain- or program-controlled valves, those equipped with manually operable valves also use HV ； XV is typically used in sequential or programmable valves with multiple input variables
HV is a manual control valve, and XV is a interlock valve.