Dwyer 38R - Manual (Page 3)

Series 38R ••• Self-Acting Temperature Control Valves Operation, Installation & Maintenance Manual
PRINCIPLES OF OPERATION OF THE REGULATOR
The W.E. Anderson Model 38R Temperature Regulator operates on the vapor pressure principle. The thermally
sensitive bulb of the instrument contains a fluid that creates a vapor which increases or decreases in pressure as the
sensing bulb temperature increases or decreases. This vapor pressure is transmitted hydraulically to the bellows
which, opposed by the adjusting (return) spring, actuates the valve controlling the flow in proportion to the sensed
temperature at the bulb. Raising or lowering the adjusting screw will change the compression of the spring against the
bellows, thus raising or lowering the control temperature. For the most sensitive operation a nominal range should be
selected that contains the desired control point in the upper 1/3 of the nominal range. The vapor pressure response is
greater per unit of temperature change in the upper portion of the nominal range. All W.E. Anderson temperature
regulators (with the exception of the Option 3 “Fail-Safe”) are equipped with an over-range feature which allows
the bulb to be heated 100°F above the nominal range without damaging the temperature sensing system.
Recommended Working Span
Single Seat Heating Va l ve s
Double Seat Heating Va l ve s Single Seat Cooling Va l ve s
Double Seat Cooling Va l ve s ˚ F (˚C) Dial Thermometer Range
R a n ge Code Nominal Range All 3-Way Va l ves ˚ F (˚C) ˚ F (˚C)
R01* 20° to 70°F (-7 to 21) 40° to 65°F (4 to 18) N/A 30° to 115°F (-1 to 46)
R02* 40° to 90°F (5 to 32) 65° to 85°F (18 to 29) N/A 50° to 140°F (10 to 60)
R03 30° to 115°F (-1 to 46) 85° to 110°F (29 to 43) 50° to 80°F (10 to 27) 30° to 115°F (-1 to 46)
R04 50° to 140°F (10 to 60) 110° to 135°F (43 to 57) 80° to 105°F (27 to 41) 50° to 140°F (10 to 60)
R05 75° to 165°F (24 to 74) 135° to 160°F (57 to 71) 105° to 130°F (41 to 54) 75° to 165°F (24 to 74)
R06 105° to 195°F (41 to 91) 160° to 190°F (71 to 88) 130° to 155°F (54 to 68) 105° to 195°F (41 to 91)
R07 125° to 215°F (52 to 102) 190° to 210°F (88 to 99) 155° to 180°F (68 to 82) 125° to 215°F (52 TO 102)
R09 155° to 250°F (68 to 121) 210° to 245°F (99 to 118) 180° to 215°F (82 to 102) 155° to 250°F (68 TO 121)
R10 200° to 280°F (93 to 138) 245° to 275°F (118 to 135) 215° to 245°F (102 to 118) 200° to 280°F (93 TO 138)
R11 225° to 315°F (107 to 157) 275° to 310°F (135 to 152) 245° to 280°F (118 to 138) 225° to 315°F (107 TO 157)
R12 255° to 370°F (124 to 188) 305° to 365°F (152 to 185) 275° to 335°F (135 to 168) 255° to 370°F (124 TO 188)
R13 295° to 420°F (146 to 216) 365° to 415°F (185 to 213) 335° to 385°F (168 to 196) 295° to 420°F (146 TO 216)
R14 310° to 440°F (154 to 227) 415° to 435°F (213 to 224) 385° to 405°F (196 to 207) 310° to 440°F (154 TO 227)
*Not recommended for single seated valves.
STANDARD RANGES
Option 3 Fail-Safe Actuators
R a n ge Nominal Range
C o d e and Recommended Working Span
R 8 1 40° to 65°F (4 to 18)
R82 55° to 80°F (18 to 29)
R83 65° to 90°F (18 to 32)
R84 80° to 110°F (27 to 43)
R85 90° to 115°F (32 to 46)
R86 110° to 140°F (43 to 60)
R89 140° to 175°F (60 to 79)
R90 170° to 195°F (77 to 91)
R91 190° to 210°F (88 to 91)
R92 205° to 225°F (96 to 107)
R93 215° to 250°F (102 to 121)
R94 230° to 265°F (110 to 129)
R95 245° to 280°F (118 to 138)
R96 270° to 300°F (132 to 149)
IDENTIFYING YOUR UNIT – Option 1 & Option 2 Actuators
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