For companies that rely on readings from metering pipeline systems, inaccurate readings can be costly. When an error is identified, the problem causing it must be identified and fixed as quickly as possible. Most companies first look for upstream obstructions when they come across an error, as these can cause readings that are off by more than 50 percent. These aren't the only issues to look for, though. If your company identifies a metering pipeline error, you should also check for pulsation-caused errors. Here's how pulsation causes errors, along with how to repair them.
Pulsation Causes Reading Errors
Pulsation refers to increases and decreases in flow rates through a capped line in a metering pipeline system. When a meter takes a reading, the reading isn't accurate because the flow rate isn't consistently that speed. It may be higher or lower, and likely oscillates. Moreover, there's no way to know whether the reading is on the faster end of the range or the slower end. Because the rate's always changing, it's virtually impossible to get an accurate flow-rate reading on a pulsating line.
There are two ways to fix errors caused by a pulsating flow, and they don't require calling a metering pipeline repair service. Your company can make all of these repairs itself.
Check Your Software's Root-Mean-Square Deviation
Your software's root-mean-square deviation is the first thing to check, because fixing it is easy. Meter readings are rarely exactly identical, but they should fall within an expected range. The range is determined by your software's root-mean-square deviation, which is a complex formula that computer programs use to predict the anticipated variance between meter readings.
The root-mean-square deviation is based on numbers that you enter into the software. If your software's projections aren't matching up with your meter's readings, then you might have entered incorrect figures. Double-check the inputs you provided the software, making sure they match the real-world variables that your metering system must deal with. These variables may include anything from a line's pitch to the outside temperature.
To find what numbers you initially gave the software, and to change them if necessary, consult your program's user's manual. It should contain a section that details how to set up and adjust the software's root-mean-square deviation.
Minimize Sound Pressure and Noise Levels
High noise levels produce sound waves, which can create enough pressure to damage finely tuned metering equipment. Control valves, control valve accessories and regulators are all susceptible to sound-induced damage. Although these components don't take readings, they manage the flow rate through pipes. When they fail, they can't prevent pulsation from developing.
If you find broken equipment, the first thing to do is to replace or repair the malfunctioning pieces. Functioning components should be installed as quickly as possible in order to prevent the pulsation from continuing.
Once the immediate threat of pulsation is curbed, the root cause should be addressed. There's currently no maximum noise level that metering pipeline systems should be kept below, but there are specific limits for their equipment. For example, regulators shouldn't be exposed to noises above 110 decibels.
Even if your company's equipment doesn't have stated noise limits, you need to reduce the sound wave pressure if it's broken a component. There are a few things you can do to lessen how much sound the metering pipeline system is exposed to:
- install insulation around pipes and equipment
- bury equipment underground, which will insulate the equipment
- use pipes with thick walls that aren't as prone to vibrations caused by sound waves
- put silencers on especially loud pieces of equipment
At times, you may have to call a metering pipeline repair service to fix a meter error. First, however, you should check for pulsation-caused errors. They're easy to fix. Finding and fixing them could save you a phone call to a repair company.