Balancing The Auto- matic Circuit Setter Valve
The automatic flow valve is an optional end valve on the return of the factory piping package.
See Figure 20. The valve regu- lates water flow through the coil to a specific (gpm) flow rate, as ordered by the customer.
The automatic flow valve controls to the specified flow rate, pro- vided that the pressure drop across the valve is within a certain range. To verify that the
valve is operating properly, remove the protective caps from the P/T ports and measure the pressure drop across the valve with a differen- tial pressure meter. Carefully remove the P/T port connection caps, since they will be at the same temperature as the pipeline. The reading should be within the given ranges in Table 2. If the pressure drop is not within the ranges listed, the valve will not control water flow. If the valve orifice becomes clogged with debris, remove water from piping and then remove the cap of the valve body and push on the piston to dislodge any foreign matter. If this is not successful, remove the cartridge and clean.
Table 2. Automatic Circuit Setter Flow Rate Range.
Valve gpm | Pressure Drop Range (psig) |
0.5 to 8.0 | 2 to 32 |
9 to 12 | 5 to 50 |
Replace the cartridge in the field without breaking the piping line to furnish a higher or lower gpm. To do this, remove the water from the system. Remove the cap assembly containing the plug from the valve body. Grasp the cartridge by the piston to remove. Install a different spring if the pressure drop range of the valve is being changed also.
31 |
