Using Griswold Controls Valves for Fluids Other Than Water

Griswold Controls Valves – Using Fluids Other Than Water

Griswold Controls valves can control the flowrate of fluids other than water, including air.

A simple equation allows you to convert the flowrate for various liquids when you know the Specific Gravity (SG) of the liquid.
(For air conversion, please contact the factory.)

Automatic Flow Limiting Valves

To determine the required cartridge flowrate, use the following formula:

Where:

• Q = Flowrate of the cartridge (gpm)
• Q₁ = Desired flowrate of the liquid (gpm)
• SG = Specific Gravity of the liquid

Example:

The application requires 13 gpm of a liquid with a Specific Gravity of 1.58.

Since Griswold Controls does not offer a 16.3 gpm cartridge, round up and order a 17 gpm cartridge.
Inform the factory about this conversion, and they will label the valve tag as 13 GPM.

Manual Balance Valves

To determine the flowrate or pressure drop signal in a manual valve, use these formulas:

Flowrate Formula:

Where:

• Q = Desired flowrate (gpm)
• Fc = Flow coefficient (from sizing calculator or literature)
• ΔP = Signal across venturi (inches of water column)
• SG = Specific Gravity of the liquid

Pressure Drop Formula:

Important Notes

• Always confirm that the valve’s EPDM o-rings are compatible with the alternate fluid.
• EPDM chemical compatibility charts are widely available online.
• If you need assistance, please
  contact the factory.

The most common alternate liquids used in our valves are glycol-water mixes.
Below are two tables showing the Specific Gravity of propylene glycol and ethylene glycol mixtures.