Basis of calculation

1.

Determine energy demand Q [kW]

2.

Determine temperature differential (supply – return) ΔT [K]

3.

Calculate volumetric flow

Hint: you can also determine the volumetric flow using the valve slide rule.

4.

Select suitable PICV

  • Pipe connections (internally or externally threaded)
  • With or without P/T ports
  • Ideally, PICVs should be selected such that they operate at about 80 % of their maximum flow, enabling them to deliver spare capacity, if required.

⇒

Determine dial setting using volumetric flow/dial presetting table, cf. Volumetric flow/dial presetting

 

Example

Given is a heat exchanger with:

1.

Energy demand: Q = 1.9 kW

2.

Temperature differential: ΔT = 6 K

3.

Volumetric flow

4.

The valve shall have connections with external threads to ISO 228-1 and size DN 15.

  • PICV selection:
    VQP46.15L0.5 (externally threaded connections, no pressure test points P/T, nominal volumetric flow 520 l/h)

5.

Volumetric flow: 270 l/h

Dial setting: 2.6