Example - PENN Controls - LIT-125683 - V243 - V43 - Pressure Actuated Water Regulating Valve - V243 High Pressure Refrigerant - V43 Low and All‐Range Pressure Refrigerant

In this example, the required flow for an R-404A system is 300 gpm. The cooling tower pump discharge pressure is 30 psig, and the condenser manufacturer's table gives a pressure drop of 8 psid through the condenser. The pressure drop through the installed piping, fittings, and valves is approximately 12 psi.

Maximum Water Flow Required = 300 gpm

Water Pressure Available= 30 - (12 + 8)

Water Pressure Available= 10 psid

You need to select the proper valve size. The proper size valve is indicated by the flow chart that slightly exceeds the maximum required flow when the valve is wide open.

As indicated in Figure 2, the correct valve for this application is a 3-in. medium-pressure (160/260 psi), noncorrosive, commercially constructed V43 Series Valve. The maximum water flow that a 3-in. valve can deliver (330 gpm) under the stated condition is slightly greater than the maximum water flow required (300 gpm).

Figure 1. Example values

Figure 2. Correct valve size for the application

Select the valve type from Table 3 through Table 5.