WorksheetsQuiz 10 : Belimo 250821
Total questions: 10
Worksheet time: 11mins
Pressure independent control valves (PICV) are often supplied by SCA but....
What exactly is "pressure independent"?
Equal percentage flow characteristic at any operating pressure
Maintain differential pressure across valve by manually adjust its shaft position
Constant flowrate regardless of pressure fluctuation
Able to operate & withstand any pressure condition
Main energy efficiency/saving features of PIFLV & PIQCV?
Dynamic balancing
Zero leakage (Ball valve design)
Self cleaning (Ball valve design)
Brushless motor
Common positioning / application of PIFLV & PIQCV?
Fan coil unit
Large AHU unit
Chilled beams
Heating/Cooling ceilings
Assume current PIFLV flow = 0.5 l/s..... If inlet pressure/flow increases to 0.8l/s
How will the flow limiting disc response to maintain chilled water flowrate?
Remain unchanged due to pressure independent
1. Differential pressure across valve increases
2. O-ring in disc begins to expand & restrict flow
3. Flow reduces to set point
1. Differential pressure across valve increases
2. O-ring start relaxing to allow more flow to pass through
3. Flow returns to set point
PIFLV will modulate by reducing its valve opening which lowers the flowrate & differential pressure
Assuming PIQCV is now operating at 0.25 l/s, differential pressure ( ΔP ) of 200 kPa.
How would pressure regulator & flowrate respond under scenario 1 & 2?
1 : Isolating valve before entering PIQCV is now turned half open
2 : Pump head increases (Higher inlet flow and pressure)
PIQCV still within working ΔP under these circumstances
1. ΔP between P1 & P3 + pressure regulator position remained
2. ΔP between P1 & P3 ↑ , regulator opening & flow ↓
1. P3 > P2; backflow occurs
2. P1 > P3; regulator opening & flow ↓
1. P1 > P2; regulator opening & flow ↑
2. P3 > P1; pressure regulator maintains its opening position
1. ΔP between P1 & P3 ↓ , regulator opening & flow ↑
2. ΔP between P1 & P3 ↑ , regulator opening & flow ↓
Which of the following statements about PIQCV & PIFLV are "FALSE"?
Behaves as pressure dependent valves whenever differential pressure is under or exceed its working range
Both are equal percentage flow characteristic control
Fouling/Clogging increases cooling coil consumption to cool down air which results in energy losses
Vmax of PIQCV & PIFLV can be configured by using an end clip stopper
PIQCV comes with "PT port" option. Generally, they are used for ______
Optimize pump performance
Commission & troubleshoot systems
Configure Vmax value of PIQCV
Measure differential pressure and flowrate across the valve (Red port = ↑ kPa connection)
Site engineer gave you a call. He informed you that one of his operator had messed up the "end stop clip" position for C220QPT-D + CQ230A.
He is now asking where the clip has to be placed to set Vmax = 250 l/h
"4 -"
"6 +"
"5+"
"6 -"
C215QPT-D + CQK24A-SR
Based on the model above, what information can be gathered?
2-way valve, DN 15, Nominal flow = 0.11 l/s
Fast running with electronic fail safe, AC/DC 24 V, Modulating Control
3-way valve, DN 15, Nominal flow = 0.58 l/s
Spring fail safe, AC 24/230V, On/Off Control
2-way valve, DN 15, PT port option, Nominal flow = 0.27 l/s
Non-spring, AC 24 V, Modulating Control
2-way valve, DN 15, PT port option, Nominal flow = 0.11 l/s
Electronic fail safe, AC/DC 24 V, Modulating Control
In comparison, there are some difference between PIFLV and PIQCV.
Select the relevant points...
PIQCV = on/off, 3-point & modulating control
PIFLV limited to only On/Off control
PIFLV does not requires end clip setting on actuator
Both type have exact flowrate capacity and range of actuator models to pair with
Both function with built-in pressure regulating mechanism & control valve under a single unit
