news » Showerhead performance

	11/22/2002
	Showerhead performance
	Frederick Luedke
	Following the imposition of national flow rate standards for the US by Federal statute (EPAct “92”), getting a good shower has become a national quest. Many manufacturers, at least in the beginning, were content with meeting the maximum flow rate requirement of 2.5 gpm @ 80 psi by simply reducing the diameter of the waterway. This may have been fine for a consumer on a municipal water supply delivering 80 psi of water pressure, but it was far from satisfactory for the consumer in the suburbs on a well delivering 45 psi at point of entry and much less than that to the second floor shower. At the other end of the spectrum, a consumer in a high-rise apartment building might have 100 psi water pressure, which might be too much water when delivered through a showerhead designed for 60-80 psi, especially if there is a concern about conserving water. Fortunately, there is solution to this dilemma: a showerhead flow regulator. A flow regulator is defined in the glossary on this website as a flow control device that supplies a constant flow of water regardless of line pressure. This means that the suburban consumer on a well can get the same full flow from his showerhead at 30 psi as the municipal water consumer gets from his at 80 psi, and neither of the showerheads including the one in the high pressure household ever delivers more than the maximum 2.5 gpm. If you are interested in how this is done, please see the flow regulator section of this website for a complete description of the design and function of flow regulators. To the relief of consumers nationwide, many showerhead manufacturers are using sophisticated NEOPERL® flow regulators to enhance the performance of their products and the satisfaction of their customers. As with most things, however, it is not always as simple as it seems to achieve good showerhead performance, depending on the complexity of the showerhead. In the case of a showerhead that has a wide-open waterway, the flow regulator is free to do its job and deliver the desired water flow across the pressure range. However, as the complexity of the showerhead increases, its built-in flow resistance may increase as well, creating backpressure that can impede the performance of a flow regulator. NEOPERL® has flow regulators that are able to overcome the effects of backpressure in the showerhead and optimize available water flow across the pressure range. However, it is important to understand that the flow regulator cannot increase water flow beyond what the waterway will allow. A flow regulator can only make available as much water as the showerhead allows to pass at lower pressures and to limit flow at higher pressures to the allowable maximum. NEOPERL® provides a choice from a wide range of flow regulators, including some that have been specifically designed for the showerhead application. In addition to the enhancement of flow, these flow regulators provide for easy assembly and facilitate the achievement of the 8-pound pullout force required by ANSI ASME A112.18.1. The trailing (upstream) edge of the flow regulator has a flexible lip that will provide the necessary retention force when used in a bore with a bump or undercut groove in the bore surface. This flexible lip also has the capability of providing the desired pullout force when used in a bore that has a controlled degree of surface roughness. With any of these methods, the necessary retention force can be achieved without the need for an extra retaining ring or clip. We encourage you to consult with our technical specialists at an early stage in your design process so that we can assist you in matching the right flow regulator to your showerhead.