Powers 420U Series Under-the-Counter Thermostatic Tempering Valves - Manual (Page 7)

DIMENSIONAL DATA AND CHECKSTOPS
Figure 8. Nameplate
SIZING
The flow chart below indicates the Hydroguard Series
420 discharge capacity in gpm for various pressure
differentials (the difference between the lowest inlet
pressure and the discharge pressure at the valve).
Valve sizing affects the performance and reliability of
the valve. Under- or over-sizing of the mixing valve(s)
can cause poor operation and possibly injury.
Warning: This is a water tempering device and is not
intended or designed for point-of-use shower applica-
tions.
There is no limit stop. It is strongly recom-
mended that checkstops be installed with this valve
even when a downstream shutoff is used.
MODEL IDENTIFICATION
To be sure you are installing appropriate parts into your
valve, determine the model number. The easiest way to
do that is to look at the date code (found on the name-
plate of the valve). The date code (not to be confused
with the product or part number) is a four-digit code. Its
purpose is to record the model/version number of the
product itself and the date of manufacture. (See circle
"B" in the figure below for location of date code.)
In the example below, the Date Code is labeled by cir-
cle "B". The first digit, 8, indicates the model number.
The nameplate also indicates the temperature range of
the valve. In the figure below, circle "A" shows the loca-
tion of the temperature range: "115" (a standard valve).
9 1 ⁄ 16
(230)
Type D
7 3 ⁄ 4
(197)
Type A, C
5 7 ⁄ 8
(149)
Type E
7