Valves float type

If a check valve is used in a system without an arrestor, excessive pressure may be exerted on the system when the reversing water column is violently stopped by the check valve. If a float-type air vent is located between the check valve and the closing valve, the float could easily be ruptured. 

FIGURE 3-16. Ventex (float type) fast-acting isolation valve (Eckhoff 1997). 

A float-type FM regulator type is primarily employed on packaged FT boilers. It has a float chamber located at the NOWL and is connected to the steam-water areas of the boiler. When the water level falls, the float drops and mechanically moves a mercury switch (or electronic switch), which in turn actuates the FW regulator valve. 

Valves are used to control the water flow through the water lines of the cooling tower distribution system. Valves used for this type application include stop valves, flow control valves and float control valves. The types of valves, quantity required and complexity of design are dictated by the type and size of tower. 

A simple example of an area meter is a gate valve of the rising-stem type provided with static-pressure taps before and after the gate and a means for measuring the stem position. In most common types of area meters, the variation of the opening is automatically brought about by the motion of a weighted piston or float supported by the fluid. Two different cyhnder- and piston-type area meters are described in the ASME Research Committee on Fluid Meters Report, op. cit., pp. 82-83. 

Fractionation Research, Inc. Report of Tests of Nutter Type B Float Valve Tray, July 2, 1964 from Nutter Engineering Co. 

A variety of fast-acting valves are available, inclnding slide gate, flap (bnt-terfly), and float (poppet) valves. Slide gate and flap type valves are actn-ated (closed) npon a signal from a detector (sensor) in the pipeline between two items of interconnected process eqnipment. The detector sends a... 

The flash vessel should be fitted with a float or inverted-bucket type steam trap to the condensate discharge line, and also a pressure relief valve to prevent excess pressure buildup, as may happen if the demand for LP steam drops below the flash steam production rate. 

There are two major types of cryogenic tanks one used primarily for liquid dispensing (see Fig. 6.6 and Fig. 6.7) and another used primarily for gas dispensing (see Fig. 6.6 and Fig. 6.10). Both are similar in size, both have rings of sheet metal around their tops to protect their valves from impact, and both have float devices on the top that indicate approximate liquid volume. 

Various types of valve arrangements are used for the valve-tray towers. Some of these are liltable disk-type valves which come as a cap with each riser. As the vapor rate increases, the valve lifts to provide a larger opening until it reaches a limit point which still directs the vapors horizontally into the liquid. Float-valve trays are designed to operate on the same principle as the liltable disk-type valves except that a floating pivotal valve is used hi each cap. 

Float Flange Conn. Slxe Drilling Plug Type Valve Balanced Parabolic V-Port or Equal ... 

In the operation of a downflow-type saturator, water is introduced at the top of the saturator tank (there is an air gap to avoid the possibility of a cross-connection) and the level is regulated with a float-operated controller valve on the water supply line. The water then trickles down through the bed of sodium fluoride solids the solution is clarified in the sand and gravel filter bed and ends up as a clear, saturated solution at the bottom of the tank where it is withdrawn by the feeder. The fluoride-water solution pump withdraws the solution and delivers it into the water system at a desired dosage rate. Operator attention is required only to ensure that an adequate quantity of sodium fluoride solids is kept in the saturator and that the saturator is kept in a reasonably clean condition. 

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