Piping length

Table 1. Required Straight Pipe Lengths for Orifice Plates, Nozzles, and Venturis ...

The pressure drop due to fricdional losses is proportional to pipe length L for fully developed flow and may be denoted as the (positive) quantity AP Pj - P2. 

For laminar flow the losses in sudden contraction may be estimated for area ratios Ao A < 0.2 by an equivalent additional pipe length Lc given by... 

Figures 26-63 and 26-64 illustrate the significant differences between subcooled and saturated-liquid discharge rates. Discharge rate decreases with increasing pipe length in both cases, but the drop in discharge rate is much more pronounced with saturated liquids. This is because the flashed vapor effectively chokes the flow and decreases the two-phase density.

The maximum value for G,p is G,, evaluated with zero pipe length. Denoting this value as G,, Fig. 26-68 plots the dimensionless mass... 

Use hard piping where possible Minimize pipe lengths where possible... 

Table A. I provides, for a particular rate of discharge in GPM. the friction loss in pipes for every 100 feet of straight pipe length, reasonably smooth and free from incrustation.

Friction loss in bends, reducers, elbows etc. are provided in Table A.2 in equivalent pipe length. 

Total equivalent length of pipe (assuming that every fitting has an average 5 m of equivalent pipe length, to account for friction) = 1000 + 25 X 5... 

Table A.2 Friction in fittings in equivalent of pipe length (ft)...

Water pipe length 2 to 4 m, 1.3 m deep soil pipe length 12 m, 1 m covering. The disbonding is clearly time dependent. 

The Lapple charts for compressible fluid flow are a good example for this operation. Assumptions of the gas obeying the ideal gas law, a horizontal pipe, and constant friction factor over the pipe length were used. Compressible flow analysis is normally used where pressure drop produces a change in density of more than 10%. 

The most difficult part of a field test is the flow meter, if it wasn t planned in the construction phase. There is no way to simulate a meter run if you don t have the proper pipe length. Figure 10-8 is an example of the requirements. An ASME long radius flow nozzle is preferred by the author, though a short throat venturi will do. The probability is that an orifice is all that will be available. It should be examined before and after the test to verify not only the bore diameter, but the finish. The bore should... 

The following analysis enables one to calculate the diameter of a pipeline transporting any compressible fluid. The required inputs are volumetric flow rate, the specific gravity of the gas relative to air, flow conditions, compressibility factor Z where Z is defined by nZRT = PV, the pressure at the point of origin and the destination, the pipe length, and pipe constants such as effective roughness. The working equations have been obtained from the literature. Since the friction factor... 

Reynolds number for the fluid being released. For sharp edged orifices with Reynolds numbers approaching 30,000, it approaches 0.61. For these conditions, the exit velocity of the fluid is independent of the size of the hole. For a rounded opening, Cj approaches 1. For a short section if pipe (length/diameter > 3), Cj = 0.81. For cases where is unknown or uncertain use C. = I i[Pg.338]

The temperature difference may not remain constant throughout the flow path. Plots of temperature vs. pipe length for a system of two concentric pipes in which the annular fluid is cooled and the pipe fluid heated are shown in Figures 2-2 and 2-3. When the two fluids travel in opposite directions, as in Figure 2-2, they are in countercurrent flow. When the fluids travel in the same direction, as in Figure 2-3, they are in co-current flow. 

Pipe length from suction pipeline to suction scrubber... 

Pipe length from scrubber to suction pulsation dampeners... 

Pipe length from discharge pulsation dampeners to cooler... 

Pipe length from discharge scrubber to pipeline... 

Where the pipe run contains similar ends (closed-closed or open-open), prohibited pipe lengths are ... 

A radial force on the pipe watt behind the flame front. For a closed pipe, this remains constant (at abont STi) everywhere for a deflagration, bnt decays from abont 20Ti to STi behind the detonation over most of the pipe length. 

For deflagrations, the dependence of overpressure and its effect on a flame arrester do not scale in proportion to pipe length, pipe diameter, or pipe length to diameter ratio. 

The flame arrester tested must be able to withstand seqnendally (a) five deflagrations with an ondet pipe length equal to 10 pipe diameters, (b) five deflagrations with a restriction in die ondet pipe... 

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