Piping velocity

The flow resistance of pipe fittings (elbows, tees, etc) and valves is expressed in terms of either an equivalent length of straight pipe or velocity head loss (head loss = Kv /2g ). Most handbooks and manufacturers pubHcations dealing with fluid flow incorporate either tables of equivalent lengths for fittings and valves or K values for velocity head loss. Inasmuch as the velocity in the equipment is generally much lower than in the pipe, a pressure loss equal to at least one velocity head occurs when the fluid is accelerated to the pipe velocity. 

Taper the diameter of the distributor pipe so that the pipe velocity and velocity head remain constant along the pipe, thus sud-stantially reducing pressure variation in the pipe. 

However, is dependent on the ratio of hole diameter to pipe diameter, pipe wall thickness to hole diameter ratio, and pipe velocity to hole velocity ratio. As long as all these are small, the coefficient 0.62 is generally adequate. 

Suggested Steam Pipe Velocities in Pipe Connecting to Steam Turbines... 

One velocity head for inlet and one half for outlet pipe velocity is close. 

Minimum pipe velocity Minimum pipe velocity (fps) for full disc lift (fps) for full disc lift... 

Minimum pipe velocity Minimum pipe velocity... 

FOR LARGER PIPES MULTIPLY 3 PIPE VELOCITY BY FOLLOWING FACTORS ... 

Minimum pipe velocity (fps) for full disc lift... 

NOTE All boiler plant operators are urged to meter the MU water consumption as an aid to calculating a material balance. Steam generation rates can be reasonably accurately determined from the fuel consumption because records of fuel costs are always maintained. Daily and weekly BD rates usually can be estimated from the use of a measuring bucket or pipe velocity table. The difference between steam production and MU represents a combination ofBD and loss of CR. 

There are many parameters influencing the size-related performance of a reactor where feed mixing is important concentrations of reactants, feed flow rate, feed pipe velocity, geometry and size of both reactor and stirrer, and stirrer rotational speed. The following remarks should be kept in mind when composing an experimental program for engineering studies ... 

V is the discharge pipe velocity, V is the volume of liquid in the tank, h is the depth of liquid in the tank and g is the constant of gravitational acceleration. 

Typical pipe velocities and allowable pressure drops, which can be used to estimate pipe sizes, are given below ... 

The relationship between flow rate, pressure drop, and pipe diameter for water flowing at 60°F in Schedule 40 horizontal pipe is tabulated in Appendix G over a range of pipe velocities that cover the most likely conditions. For this special case, no iteration or other calculation procedures are required for any of the unknown driving force, unknown flow rate, or unknown diameter problems (although interpolation in the table is usually necessary). Note that the friction loss is tabulated in this table as pressure drop (in psi) per 100 ft of pipe, which is equivalent to 100pef/144L in Bernoulli s equation, where p is in lbm/ft3, ef is in ft lbf/lbm, and L is in ft. 

If the loss coefficient is based upon the velocity through the orifice (VD) instead of the pipe velocity, the /l4 term in the denominator of Eq. (10-22) does not appear ... 

Pumping power is required to transport fluid in the streams 9, 10, and 13. Gas flow rate and density in these streams are 7.1xl0b lb/day and 0.44 lb/ft8, respectively. Using a 0.25 ft diameter pipe, velocity in the pipe is... 

Table 76—Values op va, v, and (va — v) for Manitoba Wheat Moving in a Vertical Pipe. (Velocities Expressed in M per Sec)...

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