1. Introduction
To give the best performance, KROHNE flowmeters must be installed in a correct way. Important instructions should be taken into consideration, like the inlet and outlet length, pipe to be completely filled, direction of the flow, etc. Depending on the measuring principle of each device, the guidelines will differ. In this article we will explain the installation instructions for Vortex flow meters.
The article cover the following topics:
- Recommended installation positions.
- Recommended installation positions in case of measuring liquids.
- Recommended installation positions in case of measuring gases or steam.
2. Recommended installation positions
- A straight inlet runs of 20 DN (15 DN is also possible in case of OPTISWIRL 4200) the pipe diameter is needed for Vortex flowmeters.
- Control valves should not be installed upstream from the device. If this cannot be avoided a distance of at least 50 DN must be guaranteed.
- After pipe diameter reductions a distance of 20 DN should also be kept in front of the device.
- An inlet run of 20 DN is enough for a single bend, because of the changed flow profile, longer inlet runs, in this case 30 DN are needed for a double bend.
- Outlet runs should be straight and at least 5 DN in length. After this, valves, pipe bends, measuring points or extensions can be installed. The same applies to other measuring points such as pressure measuring points, in this case there should also be a distance of at least 5 DN to a measuring device.
- To shorten the inlet runs from 20 DN to 10 DN. a flow straightener can be installed. This should be installed at a distance of 2 DN downstream from a pipe bend or a shut-off valve and 8 DN upstream from the measuring device.
3. Liquids Measurement
- The vortex flowmeter should be installed in such a way that it is always completely filled during operation.
- Installations upstream from an outlet or in a down pipe should be avoided as this will result in a partially-filled pipeline.
- It’s recommended to install in the lower pipe bend mounting a rising pipe when installing the device in a down pipe
- Install the device in a vertical rising pipe
- Install the device in an inclined rising pipe.
- Gas bubbles can develop when a vortex flowmeter is installed in an upper pipe bend. As gas bubbles should generally be avoided when measuring. This installation is not advisable.
4. Gases Measurement
- For measuring gases and vapors the device must be installed in such a way that condensate deposits are prevented.
- Don’t install in a lower pipe bend. These can cause constriction of the measuring cross section and thus inaccurate readings. ( installing suitable condensate separator can solve this problem).
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Install instead in an upper pipe bend.
- Shut-off devices, such as valves or flaps also create vortices, can also affect a vortex flowmeter so. Wherever possible. There should be no valves in the inlet run.
- Installing the device upstream from the control valve is recommended.
- If a shut-off valve is to be installed downstream from the device there should be an outlet run of 5 DN — the pipeline diameter.
- It’s not recommended to install the converter in a down pipe with wet gases and saturated steam since it can condensate and get into the ring orifice around the sensor and this can lead to damping and measuring failure.
- Install the converter above a horizontal pipe, under a horizontal pipe, or a vertical pipe.