Square head

Bolts shall have regular square heads or heavy hexagonal heads conforming to ASME B18.2.1 and shall have heavy hexagonal nuts conforming to the dimensions of ASME B18.2.2. 

The sperm whale, Physeter macrocephalus, is the largest of all toothed whales and the largest extant carnivore. It lives in deep waters in most of the world s oceans, though it is only the mature males that visit Arctic waters. It is recognised by its huge, square head. 

The body is stout and white or off white. Their antenna are longer than thrips, their heads are more triangular compared to a more square head for thrips. In stored grains they cause great economic loss, due mainly to the growth... 

Using a box-end wrench or a ratchet-handled socket wrench to drive lag bolts (p.86) is tedious work. I prefer to use a hand-drill brace and a modified short extension bar from a yg-in. or /2-in. socket set. Simply grind the square-holed end of the extension bar to fit the brace (1,2,3). Use a hexagonal (6-poinl) socket for hex-head lag bolts and an octagonal (8-point) socket for square-head lags (4). 

B18.6.2-1972(R1993) Slotted Head Cap Screws, Square Head Set Serene and Slotted Headless Set... 

Fig. 4 The visible wavefront of head wave in the sonnd field of square crystal...

Switching-Field Distribution. Both and have a strong relation with the recording process. determines the maximum output signal of a recording medium and hence the signal-to-noise ratio. ascertains how easily data can be recorded and erased or changed, but it also determines the maximum head field. On the other hand it also controls the ease with which data can be destroyed, eg, by stray fields. The lower the the more sensitive the medium is to all kinds of fields. In this way, influences the noise level as well. The squareness ratio S (= /Af ) can also be derived from the... 

Affinity Laws. Pump performance is affected by the rotating speed. When speed increases, the flow increases linearly, and the head increases as a square of the speed (14). 

Linearizing the output of the transmitter. Functions such as square root extraction of the differential pressure for a head-type flowmeter can be done within the instrument instead of within the control system. 

Head meters with density compensation. Head meters such as orifices, venturis, or nozzles can be used with one of a variety of densitometers [e.g., based on (a) buoyant force on a float, (b) hydrauhc couphug, (c) voltage output from a piezoelectric ciystal, or (d) radiation absolution]. The signal from the head meter, which is proportional to pV" (where p = fluid density aud V = fluid velocity), is multiphed by p given by the densitometer. The square root of the produc t is proportional to the mass flow rate. 

When the total dynamic head H is expressed in pounds-force per square inch, then... 

Head (h) varies as square of the impeller rotational speed. 

FIG. 10-67 Compressor coverage chart based on the normal range of operation of commercially available types shown. Solid lines use left ordinate, head. Broken lines use right ordinate, pressure. To convert cubic feet per minute to cubic meters per boiir, multiply by 1.699 to convert feet to meters, multiply by 0.3048 and to convert poiinds-force per square incb to Idlopas-cals, multiply by 6.895 ( F — 32)% = C. 

When points for 20-ft-long tubes do not appear in Fig. 11-41, use 0.95 times the cost of the equivalent 16-ft-Iong exchanger. Length variation of steel heat exchangers affects costs by approximately 1 per square foot. Shell diameters for a given surface are approximately equal for U-tube and floating-head construc tion. 

Horizontal pre.s.sure leaf filters. In these filters the leaves may be rectangular leaves which run parallel to the axis and are of varying sizes since they form chords of the shell or they may be circular or square elements parallel to the head of the shell, and aU of the same dimension. The leaves may be supported in the sheU from an independent rack, individuaUy from the shell, or from a filtrate manifold. Horizontal filters are particiilarly suited to diy-cake discharge. 

FIG. 29-58 Head-horsepower-capacity characteristics of a lean pump tandem-connected with a power-recovery turbine operating as the sole driver. To convert gallons per minute to cubic meters per minute, multiply by 3.79 X 10 to convert horsepower to kilowatts, multiply by 0.746 and to convert pounds-force per square inch to megapascals, multiply by 6.89 X 10 . ... 

Table A.4 Head of water in feet and equivalent pressure in pounds per square inch ...

Table A.5 Pressure in pounds per square inch and equivalent head of water in feet...

Head = H Liquid force measured in feet of elevation. H can be converted into pounds per square inch (psi). This is di.scussed in Chapter 2. 

Head, H, ehanges directly proportional with the square of the ehange in veloeity, H a. N2. 

Wliere N = the speed of the pump/motor in revolutions per minute Q = the square root of the flow in gallons per minute at the Best Efficiency Point BEP. For double suction pumps, use A BEP Flow. NPSHr = the net positive suction head required by the pump at the BFiP. 

The measurement of the linear velocity as a function of shaft RPM can be done at room temperature and pressure in air. It is best to do this on the catalyst already charged for the test. Since u is proportional to the square of the head generated, the relationship will hold for any fluid at any MW, T, and P if the u is expressed at the operating conditions. The measurement can be done with the flow measuring attachment and flow meter as shown in Figure 3.5.1. 

Head varies directly with the square of impeller diameter and speed. 

The equations have been expressed as proportionals however, they can be used by simply ratioing an old to a new value. To add credibility to fan law adaptation, recall the flow coefficient, Equation 5.19, The term Qj/N is used which shows a direct proportion between volume Qj and speed N. Equation 5.12 indicates the head, Hp, to be a function of the tip speed, squared. The tip speed is, in turn, a direct function of speed making head proportional to speed. Finally, the power, Wp, is a function of head multiplied by flow, from which the deduction of power, proper tional to the speed cubed, may be made. 

With the introduction of the new instruments, speed is basically taken for granted. It is a very important parameter for reciprocating compressors, however, because speed is one of the factors in generating displaced volume. For the axial and the centrifugal compressor, speed offers a multiple influence. In the fan laws stated in Chapter 5, speed was the common parameter in both capacity and head. In fact, since head is proportional to speed squared, it becomes quite important that the speed be accurate. 

One of the most important parameters to measure is speed, yet it is often overlooked. The fan law in Chapter 5 states that for a centrifugal compressor, the head is proportional to speed squared. For an axial, the sensitivity to speed is as great or greater. Capacity is directly proportional to speed on all compressors, both the positive displacement and the... 

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