In the valve installation process, we are easy to fall into these nine misunderstandings.
Bolt too long
The bolt on the valve has only one or two threads over the nut. It can reduce the risk of damage or corrosion. Why buy a bolt longer than you need? Usually, the bolts are too long, because someone doesn't have time to calculate the correct length, or the individual doesn't care what the end result looks like. This is a lazy project.
Control valve is not isolated separately
Although the isolation valve takes up valuable space, it is important to allow personnel to work on the valve when maintenance is required. If the space is limited, if the gate valve is considered too long, at least the butterfly valve is installed, it takes up almost no space. Always remember that it is easier to work and perform maintenance tasks more effectively when you have to stand on top for maintenance and operation.
No pressure gauge or device installed
Some utilities like to calibrate the tester. These facilities usually provide a good connection test device for their field personnel, but some devices even have an interface to the accessory. Although not specified, it is designed so that the actual pressure of the valve can be seen. Even with supervisory control and data acquisition (SCADA) and telemetry capabilities, someone will be standing next to the valve at some point, and it is convenient to see what the pressure is.
Installation space is too small
If it is very troublesome to install a valve station, it may involve excavating concrete and so on. Do not try to save the cost by making it reduce the installation space as much as possible. Basic maintenance in the later stages will be very difficult. Also keep in mind that the tool can be very long, so space reservations must be set so that the bolts can be loosened. It also needs some space, which allows you to add devices later.
Not considering post-disassembly
Most of the time, the installer understands that you can't connect everything together in a concrete room without the need for some type of connection to remove parts at some point in the future. If all the parts are tightly tightened and there are no gaps, it is almost impossible to separate them. Whether it is a slot coupling, a flange joint or a pipe joint, it is necessary. In the future, it may sometimes be necessary to remove parts, and although this is usually not a concern for the installation contractor, it should be the concern of the owner and the engineer.
Concentric reducer horizontal installation
This may be nitpicking, but it is also worthy of attention. The eccentric reducer can be installed horizontally. Concentric reducers are mounted on vertical lines. In some applications it is necessary to install on a horizontal line, using an eccentric reducer, but this problem usually involves cost: concentric reducers are cheaper.
Valve well that does not allow drainage
All rooms are wet. Even when the valve is started, when the air is discharged from the bonnet, the water will fall on the floor at some point. Any one has seen a flooded valve at any time in the industry, but there is really no excuse (unless, of course, the entire area is submerged, in which case you have bigger problems). If the drain cannot be installed, use a simple drain pump, assuming a power source. In the absence of power, a float valve with an ejector will effectively keep the chamber dry.
Does not exclude air
When the pressure drops, air is expelled from the suspension and transferred to the pipe, which can cause problems downstream of the valve. A simple bleed valve will get rid of any air that may be present and will prevent downstream problems. The bleed valve upstream of the control valve is also effective because the air in the pilot line can cause instability. Why not remove the air before it reaches the valve?
This can be a minor problem, but it is always helpful to have spare taps in the chamber upstream and downstream of the control valve. This setting provides convenience for future maintenance, whether it is connecting hoses, adding remote sensing to the control valve or adding a pressure transmitter to SCADA. For the small cost of adding accessories during the design phase, it significantly increases usability in the future. It makes the maintenance task more difficult because everything is covered by paint, so the nameplate cannot be read or adjusted.
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