Floating level indicators

If you use ball-float level indicators, compare the size of the balls with those of the branches on the top of the vessel. If a loose ball could lodge in one of the branches, protect the branch with a metal cage, or use another type of level indicator. 

The middle gauge cock is located at the boiler NOWL. Boilers operating at more than 250 psig have either two gauges or one gauge and an electric or electronic level indicator. Low water alarms are either float types or weight types. 

An instrument to measure the specific gravity (SG) of fluids. Typically a small, calibrated, and bottom-weighted glass or metal cylinder that floats to a level indicating the SG. 

As shown in the figure, float gaging is implemented using a float that rests on the surface of the liquid inside the float chamber. As water or wastewater enters the tank, the liquid level rises increasing the head. The increase in head causes the liquid to flow to the float chamber through the connecting pipe. The liquid level in the chamber then rises. This rise is sensed by the float which communicates with the liquid-level indicator. The indicator can be calibrated to read the liquid level in the tank directly. 

Add 200-300 lb of coarse crystalline sodium fluoride (20-60 mesh coarse crystal). (Do not use powdered NaF or fine crystal.) Make sure the sodium fluoride surface does not interfere with float and float rod of the level indicator. Add water to keep down the dust and to assist in leveling the fluoride surface. 

Formation of emulsions that can confound interface level measurements Leak in float type level indicators... 

Specially sealed level indicator tubes are provided on the boot of the tower. Either a transparent tube is attached to see the top of the indicator rod attached to a float or a magnet is attached to the top of the rod. 

Plasticizer level indicators are essential to protect storage tanks from overflows. Differential pressure gauges and floating type indicators are used for the measurement of tank levels. It is possible to calibrate level gauges in volumetric units or to indicate depth of liquid. Level indicators can also have transmitters and these may be related to high level... 

Tank level measurement relies on nickel or Monel flush diaphragm d/p cells or nickel float-type indicators. Figure 11.48 shows both types. 

This paper presents a quantitative description of a floating insulation for the surfaces of cryogenic fluids stored in open-topped dewar flasks. The technique makes use of polystyrene beads, which provide good thermal insulation, conform to a complex surface geometry—such as partially immersed equipment—and act as a good electrical insulator as well. Since the beads float on the liquid surface, they need not be removed when refilling the container and provide an easily visible liquid level indication. 

Level indicators A float or visible reference mark used to indicate the electrolyte level within a cell. 

The measurements of Phillips and Murphy [1.49, 1.50] were made with the method of a capillary viscometer with a floating level (without pressure unloading) at Reynolds numbers from 50 to 700 the results occupy an intermediate position between the data in [3.35] and [2.38]. However, comparing these results with new experimental values [2.4, 2.13] obtained using capillary viscometers of advanced design indicates that discrepancy rises with increasing temperature and reaches 12% at 347 K. It is pertinent to mention that in Ref. [1.50], the information necessary to analyze the measurements in detail is absent. Therefore, it is not possible to give a simple explanation for such a considerable deviation. 

Fig. 8-20. HRE-2 float-type level indicator (covers a 5-in. range at psi-2000 operating pressure).

Liquid-level measurements. Instruments arc available for both on-off and continuous level measurements. On-off measurements are made with modified automotive-type spark plugs in which a long rod is used in place of the normal cent( r conductor of the spark plug. To olitain a continuous level measurement, the fluid head is measured with a differential pressure in.strumc iit. The pre.ssure reciuired to bubble a gas into the fluid is compared with the pressure above the liquid to obtain the fluid head. Resistance probe and float types of level indicators are available for use in liquid-metal. systems. 

If it is not possible to utilize the fluid itself for level indication, the liquid level may be obtained in a roundabout manner by means of a stainless-steel float. A stainless-steel tube long enough to protrude from the tank is attached to the float. A short length of cold-rolled steel rod is contained in the uppermost section, which is completely enclosed so that no liquid can come in contact with it. The liquid level is obtained by locating the position of the cold-rolled steel rod with a search coil wound about a tube concentric with the one protruding from the tank. 

The shielding-water switch, which consists of a water-tight micro switch and an actuator connected to a float bob, indicates whether or not the shielding water level is at the proper height in the water tank. 

The containers for water softener and clarifiers are situated in the door of the dishwasher. The reed sensor is mounted next to the plastic casing that contains a magnet in a protective foam housing, floating on the liquid. When the level drops to a certain point, the floater activates the reed sensor, which in turn directly operates an indicator light on the front panel. The operator of the dishwasher is then alerted that softeners and/or clarifiers need to be refilled. 

Studies conducted by Mechanabve Institute [1,2] indicate that tantalite and columbite can be floated using sodium oleate. Figure 23.1 shows the effect of level of sodium oleate... 

Some time is needed for the constructed wetland to operate smoothly and at the intended low cost level. In particular, the algae and floating aquamats need several years to reach full performance, so that the filter adsorbents are needed during this period. The frequent replacement of these filters adds considerably to the cost. Stand-by of the conventional treatment plant, which is required by the regulators to cope with any unexpected malfunctioning is another cost factor which makes the wetland more expensive in the early years of its operation. The cost breakdown is summarized in Table 2, which also indicates those components which can be significantly reduced over time. 

Lavoisier directed sunlight at tin floating on a block of wood in a glass jar inverted over water. As the tin reacted to form a powder, the water level in the jar rose, indicating that some of the air originally in the jar had taken part in the reaction. 

The operation of the chain float is similar to the ball float except in its method of positioning the pointer and its connection to the position indication. The float is connected to a rotating element by a chain with a weight attached to the other end to provide a means of keeping the chain taut during changes in level. 

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