CVHE-SVX02M-EN
43
For CenTraVac™ chillers using a rupture disk relief:
• L = equivalent length of discharge piping, ft (m)
• C
r
= rated capacity as stamped on the relief device
in lb/min (kg/s), or SCFM multiplied by 0.0764 lb/
min (convert multiplier in lb/min to kg/s for SI)
C
r
= CC value from the preceding table (convert CC
in lb/min to kg/s for SI)
• f = Moody friction factor in fully turbulent flow
• d = inside diameter of pipe or tube, in. (mm)
• ln = natural logarithm
• P
2
= absolute pressure at outlet of discharge piping,
psi (kPa)
• P
0
= allowed back pressure (absolute) at the outlet
of pressure relief device, psi (kPa)
P
0
= (0.50 P) + atmospheric pressure
NNoottee:: For rupture disks on CenTraVac
™
chillers, P
is 15 lb (6.8 kg). Atmospheric pressure is at
the elevation of the installation above sea
level; a default value is the atmospheric
pressure at sea level, 14.7 psi (101.34 kPa).
VVeenntt PPiippiinngg