At 0 PSID, the Hays Mesurflo orifice and diaphragm are allowing  water to flow freely through the valve.
0 PSID
	At 15 PSID, the diaphragm has moved against the orifice plate and begun controlling water flow.
15 PSID
	Due to the nature of the Hays Mesurflo orifice and diaphragm, back flushing the valve is possible.  This feature is not available in other manufacturers valves.
Reverse Flow

   Hays Mesurflo valves come in a variety of shapes and sizes.  You may choose from the 2511 which is a basic copper tube valve or you may want a more sophisticated valve in the Y-Ball Mesurflo  which offers both a ball valve, flow control, P/T test ports and in most models, a union with interchangeable end fittings.

Also available in the Mesurflo line, are the Y-Ball Strainers.  These versatile valves offer you all of the features you would need to make a coil connection including: Wye strainer, ball valve, union and P/T test ports.

No matter what you need in a flow control valve, Hays Fluid Controls has them from 1/2" - 20" and from .5 GPM to 6000+ GPM.