Teledyne 4220 installation and operation guide Rings

4220 Flow Meter

Section 4 Submerged Probe Installation

The spring ring may need anchoring. Under conditions of high velocity (greater than 5 feet per second or 1.5 meters per second), the ring may not have sufficient outward spring force to maintain a tight fit inside the pipe. The ring may start to lift off the bottom of the pipe in a waving fashion, or may even be carried downstream.

This problem is more prevalent in the larger diameter pipes (10", 12", and 15", and in pipes with smooth inside surfaces, such as plastic pipes). If any of these conditions are present, or if movement of the mounting ring is detected or suspected, you must anchor the ring in place. You can do this by setting screws through the ring into the pipe, or by other appropriate means. If there is a problem with the smaller diameter rings, it may be suf- ficient to simply increase the outward spring force of the ring by bending it into a less round configuration.

4.3.2Universal Mounting For pipes larger than 15" in diameter, Teledyne Isco offers the

Rings	adjustable Universal Mounting Ring (also known as the “Scissors
	Ring”). This device consists of two or more metal strips that lock
	together with tabs to form a single assembly. There is a base
	section where the sensors are mounted, one or more extension
	sections (usually), and a scissors section at the top that expands
	the entire assembly and tightens it inside the pipe. The scissors
	section contains a long screw that increases the length of the
	section as it is tightened.
	The assembled scissors rings fit pipe diameters from 16" to 80".
	Secure the unit in place by tightening the scissors mechanism
	with a 5/8" socket wrench or other suitable tool. Ring sections are
	.040" thick half-hard 301 stainless steel sheet. All other parts are
	also stainless steel, except for the plastic cable ties in the
	hardware kit.
	Each extension, 1, 2, 3, and 4, adds 9.0", 21.5", 31.5", or 41.5",
	respectively, to the circumference of the ring. Used alone, the
	base section fits pipe that is approximately 16" to 18" in
	diameter. The 9.0" (the smallest) extension exists so that in
	larger pipe sizes, where large variations in circumference can
	occur, you can use one or two of these extensions to take up or
	remove slack, to bring the scissors mechanism into a position
	where it can be effectively tightened.

Figure 4-4contains drawings of the rings and a table that indi- cates the recommended part configurations for some common pipe diameters. The formula to use when deciding upon a config- uration is:

diameter x π = circumference (π = approx. 3.14159)

Once you have the circumference of the pipe, add up the dimen- sions of different ring combinations until you find one that will fit, leaving 3.5" to 16" of room for the scissors mechanism.

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