7/28/2019 PICV vs Manual Balancing With Dp Controller
1/1
Conparison Table Between Pressure Independent Control Valve vs
Manual Valve with Differential Pressure Controller
FLOWCON
Low head requirement with just 1 valve
(Typically at 16/35kpa depending on index Loop)
Pressure Independent Control Valve require at terminal only
Lowest pump head requirement
Higher head requirement for all balancing valve in series(Main,
riser, branch and terminal)( 12-20kpa)
+ Control valve(16-35kpa) + Dp Controller(10-25kpa)
Higher pump head requirement
ACCURACY +/-5% (Factory Pre-set) +/-10% (Site setting)
No time spent in calculating Cv valves
(Least nos of valves in system)
Installation time for just 1 valve
No Balancing required - Self Balancing System
Time spent in calculating Cv valves
(Most nos of valves in system)
Installation time for all valves = Time Consuming
Commissioning time for all terminal units, branches, riser and
mian
Control Valve Authority can be easily sized at 50% depending on
the available KV value for the control valve and
setting on the Dp controller in the distribution loop.
In event of a long loop with ahu and fcu, fluctuating Dp will
still occur within the control loop, which will affect the
authority and cause the controller to hunt for the setpoint
PART LOAD
OPERATION
At full/part load, design flow will always be maintained with
no
overflow at all time.At full load, design flow can be
maintained. But at part load, slight overflow with occur within the
control loop.
+ Branch return side + Terminal
PUMP HEAD
+
+
+
COST
TIME
Install at the return line with
balancing valve at the supply
connected with a capillary
tube
APPLICATION
Just 1 Pressure Independent Control Valve at terminal
Installation cost for just 1 valve
No commissioning required
Manual Balancing Valve + 2-way Control Valve(Terminal) + Manual
balancing valves + DP Controller(Branches) +
extra set of balancing valve at main, risers
Installation cost for all the valves
Expensive Balancing Instruments + Additional Labour to
commission valves
None (Pressure Independent Characteristic-Spacing Saving)Placed
at a safe distance of
2D - 5D on pipe
+
+
+
+
Static Cv valve - Tedious Cv
calculations required
Select dPL in tables, pipe size
, check desired Q < spec. Q.
Only One PICV to one Terminal(FCU/AHU)
No more additional balancing valve or dp controller require
at
main, riser or branches
Main, riser, branch and
terminal
REMARKS
VS
+
Tedious Cv calculations for authority sizing
Restricted to limited CV Value
(Control Valve often oversized; 50% Valve
Authority
PLUMBING
RESTRICTIONS
MODEL
DEFINITION
RETROFITTING /
ADDENDUM
FEATURE -
SME/SM valve controls and balances Q at varying dP
(Full Load & Part Load)DESCRIPTION
Balance Q manually @
specific constant dP
Equipment added do not require to rebalancing as the PICV
will
adjust automatically to maintain the required flowrate.
Allow project to run in phases without having to rebalance
the
system
Equipment added will require rebalancing as the DP Controller
only maintain constant Dp and balancing will be
require at terminal level for individual branch
Project running in phases will require some rebalancing of
system
OTHER
Manual Balancing ValveDifferential Pressure
Controller2-Way Pressure Dependent Control ValveSME / SM
Pressure Independent Control Valve
(Modulating Control + DP Controller + Automatic Balancing)Manual
Balancing Valve
Differential Pressure
Controller2-Way Pressure Dependent Control Valve
+ +
ENERGY
SAVINGS
1 valve --> inaccuracies, losses, head, pump head,
motor power, overall cost, time spent, energy savings
valves, inaccuracies, losses, head, pump head, motor power,
total cost, time spent, energy
savings
Control Q @ specific constant dPMaintain dP constant within
individual loop/branch
N.A.
SIZING
Dynamic Variable Cv valve -- No Cv calculations required;
simply
know the Q and tune the settings
(100% Valve Authority)
CONTROL
VALVE
AUTHORITY
Pressure Independent Control Valve Authority is always at
100%due to the in-build Dp Controller which equalize the
pressure
during variable flow in the distribution loop
With 100% control valve authority, the output odf the
controller
for the setpoint will not be affected by fluctuating DP
