Teledyne 4220 installation and operation guide Mounting Rings, Spring Rings

4220 Flow Meter Section 4 Submerged Probe Installation

Slanted Nose

Section

Flume Cap

4.3 Mounting Rings

4.3.1 Spring Rings

Slanted Nose Section – Under certain conditions - low flow rates in debris-laden small sewers, for example - the submerged probe may catch and retain the debris, obstructing the flow stream and causing erroneous level readings. To avoid this problem, use the slanted nose section. This nose section has a slanted leading edge that tends to shed debris more readily than the standard nose section.

Use the slanted nose section with caution, however, Under condi- tions of low flow and high velocity, the slanted nose section may induce a hydraulic “jump” in the flow stream that can cause erro- neous level readings.

Flume Cap – The flume cap is a small, blunt cap that replaces the nose section. Most flume manufacturers can supply flumes with a small cavity to accept an Isco probe. The probe cap pro- tects the transducer while minimizing the total length

The following sections describe sensor installation using the two options available for mounting the probe in pipes or round-bot- tomed flow streams. For pipes up to 15" (38.1 cm) in diameter, stainless steel self-expanding mounting rings (Spring Rings) are available. For pipes larger than 15" in diameter, Teledyne Isco offers the Universal Mounting Rings (Scissors Rings).

To install a spring ring, you compress the ring, slip it inside the pipe, and then allow it to spring out to contact the inside diameter of the pipe. The inherent outward spring force of the ring firmly secures it in place. A typical self-expanding mounting ring (with a probe mounted on it) is shown in Figure 4-1.

These mounting rings are available for use in pipes with inside diameters of 6" (15.2 cm), 8" (20.3 cm), 10" (25.4 cm), 12" (30.5 cm), and 15" (38.1 cm). The Teledyne Isco part numbers for the various size mounting rings available are listed in Appendix B. These part numbers include not only the ring, but also the mis- cellaneous hardware necessary to mount the sensor on the ring.

CAUTION

Always wear leather gloves when handling the rings (either type). The metal is finished, but there is still a possibility of cut- ting your hands on the edges.

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