Ten faults of valve installation
1. The bolt is too long
Only one or two threads exceed the nut for the bolts on the valve. The risk of damage or corrosion can be reduced. Why buy a bolt longer than you need? Often, the bolt is too long because someone didn’t have time to calculate the correct length or the individual simply didn’t care what the end result looked like. This is lazy engineering.
2. The control valve is not isolated separately
Although isolating valves take up valuable space, it is important to allow personnel to work on the valve when maintenance is required. If space is limited, if a gate valve is considered too long, at least install a butterfly valve, which takes up hardly any space. Always keep in mind that for maintenance and operations that must be done standing on top, it is easier to work with them and perform maintenance tasks more efficiently.
3. There is no pressure gauge or device installed
Some utilities prefer calibration testers, and these facilities usually do a good job of providing their field personnel with connection testing equipment, but some even have interfaces for mounting accessories. Although not specified, it is designed so that the actual pressure at the valve can be seen. Even with supervisory control and data acquisition (SCADA) and telemetry capabilities, at some point, someone will be standing next to the valve and need to see what the pressure is. That’s so convenient.
4. The installation space is too small
If it is a hassle to install a valve station, which may involve digging concrete etc., don’t try to save that little bit of cost by making it as small as possible in the installation space. Doing basic maintenance at a later stage will be very difficult. One more thing to remember: the tool can be quite long, so it is necessary to set up a headroom to loosen the bolt. Some space is also required, which allows you to add equipment later.
5. Does not consider later disassembly
Most of the time, installers understand that you can’t connect everything together in a concrete chamber without some type of connection that will allow for parts to be removed at some point in the future. If all the parts are tightly screwed on with no gaps, it will be next to impossible to pull them apart. It is necessary whether it is a groove coupling, a flange joint, or a pipe joint. In the future, parts may sometimes need to be removed, and while this is usually not a concern of the installing contractor, it should be the concern of the owner and engineer.
6. Horizontal installation of concentric reducers
The eccentric reducer can be installed horizontally. Concentric reducers are installed in vertical lines. In some applications where it is necessary to install at level, eccentric reducers are used, but this issue is usually related to cost: concentric reducers are cheap.
7. Valve wells that do not allow drainage
All rooms are wet. Even during valve actuation, water will fall to the floor at some point as the air is expelled from the valve cover. Anyone in the industry has seen a flooded valve at any time, but there’s really no excuse (unless, of course, the entire area is flooded, in which case you have bigger problems). If a drain cannot be installed, a simple sump pump is used, assuming power is available. In the absence of power, a float valve with an injector will effectively keep the chamber dry.
8. Does not exclude air
When the pressure drops, air is expelled from the suspension and is diverted into the piping, which causes problems downstream of the valve. A simple bleed valve will get rid of any air that may be present and will prevent downstream problems. A bleed valve upstream of the control valve is also effective as air in the pilot line can cause instability. Why isn’t the air removed before it reaches the valve?
9. Spare Tap
This may be a minor issue, but it is always helpful to have spare taps in the chamber upstream and downstream of the control valve. This setup allows for easy future maintenance, whether connecting hoses, adding remote sensing to a control valve or adding a pressure transmitter for SCADA. For the small cost of adding accessories during the design phase, it significantly increases usability in the future. Made maintenance tasks more difficult as everything was covered in paint so it was impossible to read nameplates or make adjustments.
