FLOWMETER INSTALL & COMMISSIONING
Traditional Magflow, Coriolis, Venturi, Paddle wheel, Insertion flowmeters are well known in most industries. The installation of these devices all require some form of intrusion into or cutting of the pipe. This requires planned plant shutdown, health and safety requirements and loss of production. The right sizing, flange type, earthing, sealing, electrodes, lining and a range of site specific parameters are required before the meter can be purchased or installed.
An alternative method using non-invasive flow meters provides a smarter solution.
Ultrasonic Installation Basics
The principals of flow and flow profiles for most meters are the same. Rule of thumb is to ensure a straight section of pipe 10x diameter upstream and 5 x diameter downstream of the measuring point. Accurate measurement of flow in pipes would equate to flow of traffic on a highway. A dual lane merging into one or the other way, a sharp bend, twisting road or an obstruction all change the flow profile. A control valve causes even more flow problems.
Typical installation would follow these steps.
- Establish the right location and the pipe dimensions with accurate diameter tape.
- Pipe wall thickness is easily determined with built in wall thickness gauge.
- Locate the transduces on a suitable straight section of pipe and follow the general rule for all flowmeters.
- Calibration of tanks, vessels and instruments.
- Leak Detection.
- Flow meter challenging, Inline meter validation and testing.
- Clamp the sensors on the pipe using simple mounting bracket with s/steel straps for permanent use. Cable ties, cargo straps “OKKI straps” all work.
- Final diagnostic test will identify any commissioning defects which can be rectified on site.
Benefits of Ultrasonic Flowmeters
- Retro-fitting on existing processes where the flow simply cannot be turned off – Hospitals, Universities (Particularly with on-going research projects) High rise buildings.
- Clamp-on flowmeters have an overall reduced total installation cost often eliminating OS&H, work permits, emptying the pipe, special purges (Nitrogen) cutting and welding
- Ultrasonic flowmeters are fast becoming the preferred method of metering flow in buried pipes.
Where critical in-line flowmeters have become unreliable or fail an ultrasonic clamp-on meter can be installed directly next to the failed meter without the cost of removing it.
- High pressure- since the sensors do not make contact with the medium the only limiting factor is the capacity of the pipe to withstand internal pressure. Flow of GAS pressures of 60 Bar are commonly measured.
- Upgrading or changing of pipe size. Pipes are often increased in size to accommodate larger flows which result in existing meters being redundant. Clamp on flowmeters are simply removed, reinstalled and reprogrammed to new pipe dimensions.