Page 81 - Fluid mechanics, heat transfer, and mass transfer

PIPING, SEALS, AND VALVES
58
(Continued)
TABLE 3.6 & Use of perforated diffuser-type silencers in which the
gas is made to flow through numerous small orifices
Deviation Causes and Consequences
(as small a possible, minimum diameter of 5 mm,
Reverse flow Differential pressure on joining lines, drains or dictated by considerations of blockage). Shapes can
temporary connections causing back flow of be perforated plate, cone, or bucket.
fluid resulting in undesirable reaction or & Hammer in valves will be reduced if valve opening/
over-filling, and so on. closing is made gradual than sudden. Dampening
Loss of Failure to isolate flow from sample connection,
these operations considerably reduces hammer.
containment drain and other fittings resulting in discharge
to environment. . Give recommended equivalent lengths for valves and
Breakage of sight glasses and glass rotameters pipe fittings for the estimation of pressure drops.
due to overpressure, thermal stress, or & The recommended equivalent lengths for valves and
physical impact. fittings are listed in Table 3.5.
Loss of containment due to leakages from
. Summarize operational deviations and their causes and
piping, flanges, valves, Hoses, pipe rupture,
consequences in piping systems.
collision, or improper support.
Pipe failure due to excessive thermal stress. & A summary is presented in Table 3.6.
Breakdown of pipe/hose lining.