The diverter style backwash valve is a newer style valve that offers the best possible flow of all the backwash valves. Jandy/Zodiac calls this their “2-in-1 valve”.This is a great valve to consider if you have a pool where you need to remove every possible impediment to flow.   This valve can also be retrofit to almost any other filter using the versa-couplers that Jandy manufactures.

This valve is based on the design of a Jandy valve.  Jandy, of course, is a brand name, but their name has become synonymous with this type of diverter valve.

With a Jandy valve, the “gate” moves completely out of the way when the valve is in the open position, allowing full flow of water through the valve, with virtually no restriction (i.e. almost the same flow characteristics as a straight piece of pipe).

The diverter style backwash valve uses this same design so that the valve creates no restriction in the flow.  Consider the flow differences between the different types of backwash valves at a flow rate of 100 gallons per minute.

Backwash Valve Type	Feet of Head	PSI Loss	2″ Pipe Equivalent
Multiport	13.8	6.0	171 Feet
Push Pull (Plunger)	10.3	4.5	128 Feet
Diverter	2.8	1.2	34 Feet

At a flow rate of 100 gallons per minute, a multiport backwash valve creates as much resistance to flow as adding 171 feet of pipe to the system!  By comparison, the diverter style valve adds only as much as resistance as 34 feet of pipe, which is obviously a LOT less.

Please note that at lower flow rates (i.e. variable speed pumps) the resistance will be significantly decreased and the differences between the different styles of valves will be much less dramatic.

For most systems, a push pull valve is the best option, but with systems where you need to squeeze every possible drop of flow out of the system, a diverter style backwash valve is the way to go.