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Multi-stage restriction orifice calculation

Allgemeine Diskussion » Multi-stage restriction orifice calculation Posted: 20. February 2018 - 6:45

Good day:

I need to know is the Multi-stage restriction orifice calculation module is available at Conval 10

if yes, could you please provides more data about it


Andreas Vogt

Andreas Vogt's picture

Multi-stage / multi-hole restriction orifices

Posted: 20.02.2018 - 11:33

The "stand-alone" restriction orifice sizing module supports single & multi-hole orifice sizing.

It's very common to have multi-stage / multi-hole restriction orifices downstream of a valve. Therefore, the restriction orifice sizing integrated in the control valve sizing module fully supports sizing AND recalculation of multi stage / multi-hole restriction orifices.

Even if you are only interested in the restriction orifices, you can use the control valve module to size multi-stage / multi-hole restriction orifices.

CONVAL® supports design as well as recalculation for the plates (see screenshot below) with all their parameters and dimensions.

Jeff Peshoff

Jeff Peshoff's picture

Resistance Structure

Posted: 13.04.2022 - 21:00

In Control Valve Sizing, there are options to select various types of manual valves for downstream resistors, rather than just restriction orifices.  This is a valuable feature of Conval, but there is little identifying data on such valves as the results show Cv data for these restrictors but not restrictor valve size or indication of restrictor valve opening. Therefore, is the CV res and CV tot output simply the projected Cv once the manual valve is closed enough to generate the pressure drops described in the Resistance Structure detail table?  I assume the software has a reference table somewhere for various types of restrictor valve options.

Dirk Hackländer

Dirk Hackländer's picture

Manual Valves for Downstream Resistors

Posted: 14.04.2022 - 9:55

In the table of resistors you can find details about the downstream valve(s). The downstream pipe size is used as the valve size by default. However, you can overwrite this. The Cv value shown in the table is the value to which the valve must be set in order to have the required pressure drop.

CONVAL uses design- and size-dependent valve modifiers to calculate the Cv value, choked flow conditions, cavitation and sound level for the downstream valves. You can make a more precise calculation of the downstream valve in a separate control valve calculation.

If several resistors are connected in series, the Cv values of the individual resistors are summarized to Cv,res. Cv,tot is the total Cv value of the control valve and downstream valve(s).