Pipe roughness: A measurement of the average height of peaks producing roughness on the internal surface of pipes. Roughness is measured in many locations and then averaged, it is usually defined in micro-inches RMS (root mean square).

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[hr][/hr] Piping pressure (maximum): it may be necessary in certain applications to check the maximum rating of your pipes to avoid bursting due to excessive pressure. The ASME pressure piping code B31.3 provides the maximum stress for pipes of various materials. Also the pipe flange rating will have to be checked.
for more information see

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Table of allowable piping stress from the ASME pressure piping code B31.3
[hr][/hr] Pitot pump: also know as rotating casing pump. This pump’s specialty is low to medium flow rates at high pressures. It is frequently used for high pressure shower supply on paper machines.

Pitot (Roto-jet ) pump
see

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[link Point to another website Only the registered members can access] [hr][/hr] Pressure: The application of a force to a body producing more or less compression within the liquid. In a static fluid pressure varies with height.
Fluid weight is the cause of hydrostatic pressure. A thin slice of fluid is isolated so that the forces surrounding it can be visualized. If we make the slice very thin, the pressure at the top and bottom of the slice will be the same. The slice is compressed top and bottom by force vectors opposing each other. The fluid in the slice also exerts pressure in the horizontal direction against the pipe walls. These forces are balanced by stress within the pipe wall. The pressure at the bottom of the slice will be equal to the weight of fluid above it divided by the area.


The weight of a fluid column of height (z) is:

The pressure (p) is equal to the fluid weight (F) divided by the cross-sectional area (A) at the point where the pressure is calculated :

where F : force due to fluid weight

V : volume

g : acceleration due to gravity (32.17 ft/s2)

: fluid density in pound mass per unit volume

: fluid density or specific weight in pound force per unit volume
[hr][/hr] Pressure head: an expression of energy, specifically it is energy per unit weight of fluid displaced.

[link Point to another website Only the registered members can access] We often need to calculate the pressure head that corresponds to the pressure. Pressure can be converted to pressure head or fluid column height for any fluid. However, not all fluids have the same density. Water for example has a density of 62.34 pounds per cubic foot whereas gasoline has a density of 46.75 pounds per cubic foot.

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where is the fluid density and is water density at standard conditions. Since

where is the fluid density in terms of weight per unit volume. The constant gc is required to provide a relationship between mass in lbm and force in lbf .


The quantity ( = 62.34 lbm/ft3 for water at 60 °F) is:


After simplification, the relationship between the fluid column height and the pressure at the bottom of the column is: