Prestone AF-888P Extension Life Anti-Freeze, 1 gal, Orange, Liquid

Howdy! Thank you for posting your query about the Watts 0856737 valve. Based on the information provided, it seems that you are looking for a control device to regulate the flow rate of the circulation pump in your primary circuit. The Watts 0856737 is a variable speed control device specifically designed for circulator pumps in hydronic heating systems.

The Watts 0856737 control device allows you to adjust the flow rate of the pump, which can be very useful in a situation where you want to hold back the pump just a little. By decreasing the flow rate, you can ensure that the primary circuit does not overpower the load side with too much flow. This can help optimize the performance and efficiency of your heating system.

However, it is important to note that the Watts 0856737 control device has a maximum flow rate of 5 GPM. Since you mentioned that your new circulation pump is rated to 12 GPM, this control device may not be suitable for your specific application. You should consider checking the specifications of the control device to ensure it is compatible with your pump's flow rate. Thank you for trusting PlumbersStock. Have a great day!