Hot Tap Removal of Insertion Magmeter

This short video, produced by Seametrics, outlines the procedure for removal of their insertion magnetic flow sensor from an active line. The flow sensor has been installed in conjunction with a full port ball valve that allows isolation of the sensor from the pipe once the sensor has been properly positioned. The capability to remove the sensor for inspection or other operations without disturbing the contained process can be advantageous to certain applications.

Magnetic flow measurement instruments are effective in applications with sufficiently conductive liquids. A magnetic field is produced by the sensor. As liquid flows through the magnetic field, a small electric current is produced. The polarity of the magnetic field is rapidly reversed by the unit electronics, and the resulting output signal from the sensing unit is a rapid pulse, proportional to the flow rate. The pulse can be counted by electronic devices and used for monitoring, totalizing, or control. The signal is also easily converted to a 4-20 mA or other analog signal for transmission to other instruments or devices.

Share your flow measurement requirements and challenges with process measurement instrumentation specialists. The combination of your own process knowledge and experience with their product application expertise will foster the development of effective solutions.

Understanding Hot Tapping: Insertion Flowmeter Example

Hot tapping insertion probe.

The ability to remove an insertion flowmeter probe is important for service and calibration. In many situations, it is not desirable to shut down the process and drain the pipe. In these cases, a method for removal known as "hot tapping" is preferred. Hot tapping (also known as pressure tapping) is a technique where a connection is made to an existing pipe or pressure vessel without disturbing flow or having to empty the pipe or vessel. This allows a pipe or tank to be in operation while maintenance or modifications are being done.

This video demonstrates the steps (and precautions) to remove a Seametrics flowmeter insertion probe from a live process (hot tap).  Insertion type flowmeters use a ball valve as the shut-off device and as isolation from the process media in the pipe. The video outlines the sequence of loosening the lock nut, raising the probe, then shutting off the valve before removal.

Additionally, here is a good document with more specific information on the insertion flow meter / hot tapping process:

Flow Meter Hot Tap Instructions from Instrument Specialties, Inc.

For more information on any flowmeter installation, contact:

Instrument Specialties Inc.
3885 St. Johns Parkway
Sanford, FL 32771
phone 407.324.7800
fax 407.324.1104

www.isisales.com