With the fast-moving pace of technology and innovation, valuable information that should be passed on is often glossed over. While shortcuts or quick ways to get by can reflect well on short-term budgets, they show a lack of experience and overall understanding of what makes a system viable for the long haul.
As I travel for my job, the sites and valve stations I visit always intrigue me. They either impress me with their engineering brilliance or cause me to shake my head and wonder how they were ever approved, let alone built.
Based on this experience, the following list outlines 10 common red flags that should make you question what else has been short-circuited that will lead to more maintenance and costly repairs involving valve chambers.
- Bolts that are too long. We were always taught that only one or two threads should protrude past the nut once the joint is tight. I assumed that this was to reduce the risk of damage or corrosion—or even to prevent the bolt from finding your shin as you walk past it—but it also makes economic sense. Why buy a bolt longer than you need? Typically, bolts are too long because somebody did not have time to calculate the correct length or simply did not care what the end result would look like. Bottom line: It is lazy engineering.
- Valve chambers where the control valve has no way of being isolated. While valve chambers and isolating valves take up valuable real estate, it is important to allow enough space for personnel to work on the valve when maintenance is required. If gate valves are considered too long, at least install butterfly valves, which take up hardly any space at all. Always bear in mind that, for the operators who have to work on these stations, the easier it is to work on, the greater the chance that maintenance tasks will be done effectively.
- Installations with no pressure gauges or provisions to temporarily install one. Some utilities like to have calibrated test gauges that they move from site to site. These facilities typically are good at providing connections for their site personnel to access, but what about those installations that don’t even have fittings? It always amazes me that someone is expected to set a valve with no provision to be able to see the actual pressures right at the valve. Even with supervisory control and data acquisition (SCADA) and telemetry capabilities, someone at some point will stand next to a valve and need to see what the pressure is.
- Improper gaskets. This issue usually results from poor planning, lack of knowledge or simple apathy. This mistake may not affect the operation of the valve, but it is still important to use the correct gasket. Raised flanges use ring gaskets, while flat-face use full-face gaskets. Years ago when we used to mate cast iron to steel flanges, you had to be careful about mating a raised face to a flat face because you could easily break the cast iron flange. For this reason, people were more aware of which gasket should be used. The advent of ductile iron has caused this to become a non-issue in many cases, but nevertheless, use the right gasket.
- Valve chambers with no piping allowance for the removal of parts. Most of the time, installers understand that you cannot bolt everything together in a concrete chamber without having some type of coupling to allow for component removal at some point in the future. Whether this be a grooved type coupling, a flange adapter or a pipe coupling, they are necessary. It is still shocking to see so many installations without any allowance at all.
- Concentric reducers on horizontal lines. This might seem like nitpicking, but this is a valid issue. Eccentric reducers keep the top of the pipeline at the same level, which means that air pockets are less likely to form. Concentric reducers are for vertical lines. In some applications, an eccentric reducer may not be available or even necessary, but this issue usually comes down to cost; concentric reducers are less expensive, so if a contractor can get away with them, he will.
- Valve chambers that have no allowance for drainage. All chambers get wet. Even during valve startup when air is being bled out of bonnets, water will end up on the floor at some point. Anyone who has been in the industry for any length of time has seen a flooded valve pit, but there is really no excuse for it (unless, of course, the entire area is flooded, in which case you have bigger issues). If a daylight drain cannot be installed, use a simple sump pump, assuming there is power. In cases where there is no power, a float valve with an ejector will efficiently keep a chamber dry.
- No allowances to get rid of air. Pressure-reducing valves are great at producing air. As pressure drops, air comes out of suspension and is transferred into the pipelines, which will cause issues downstream of the valve. A simple air-release valve will get rid of any air that may be present and will prevent problems downstream. An air-release valve upstream of a control valve is also effective because air in pilot lines can cause instability. Why not get rid of air before it ever reaches the valve?
- No spare tapping on the line. This may be a minor issue, but it is always helpful to have a spare tapping in the chamber upstream and downstream of the control valves. This setup provides options for the future, whether it is connecting a hose, adding remote sensing for the control valve or adding a pressure transmitter for SCADA. The small cost of adding a fitting during the design stage significantly increases the usability of a chamber in the future.
- Painting everything. Painting over everything in a valve station—valve handles, nameplates, pilot tubing, pilots, etc.—makes maintenance tasks much more difficult. You may not be able to read a nameplate or make an adjustment because everything is covered in paint. Most reputable valve companies will use fusion-bond epoxy on their valves, so nothing you could paint them with will make them better.
Remember: Doing things the right way always proves beneficial, but a culmination of shortcuts usually leads to more headaches.