Valves
Humidistats 
and 
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Engineering 
Guide
Cross 
Reference
70-6925 103
VP526 Three-Way High Pressure Water Valve
Three-way pneumatic mixing valve provides proportional control 
of hot and/or cold water in unit air conditioners and fan coil 
systems. Replacement devices are available for Johnson, Powers, 
Robertshaw, Barber-Colman, and older Honeywell devices.
• Small size permits installation where space is limited. 
• Direct-acting, rolling diaphragm actuator with integral high 
temperature plastic air connector for 1/4 in. (6-mm) O.D. plastic 
tubing. 
• Spring loaded, self-adjusting Buna-N “V”-ring packing replaceable. 
• Brass seats (integral lower, removable upper) and contoured plug 
provide metal-to-metal seating. 
• Stainless steel stem. 
• Linear and constant total flow throughout full plug travel.
Dimensions in inches (millimeters) VP526 Typical Piping Diagram
Close-off Ratings for the VP526
Valve Type: Unitary
Body Pattern: Three-way Mixing
Body Pressure: 250 psi (1724 kPa) 
Air Connections: Push on for 1/4 in. O.D. plastic tubing
Valve Action: Proportional Normally Open Ports B to AB
Controlled Medium: Water
Type of End Connection: 45 deg. SAE flare
Operating Humidity Range (% RH): 5 to 95% RH
Temperature Range: 35 F to 250 F (2 C to 121 C) 
Maximum Safe Actuator Diaphragm Temperature: 230 F (110 C) 
Maximum Diaphragm Pressure: 29 psi (200 kPa) 
CLEARANCE REQUIRED
TO SERVICE VALVE
1-1/2 (38)
MIN.
2-1/4 (57) DIA.
AIR CONNECTION 
FOR 1/4 IN. (6 MM) 
O.D. PLASTIC TUBING
MINIMUM FOR
REMOVAL OF VALVE
1-5/8
(41)
A
D
E
B
C
F
G
H
ADEBC F GH
1
1
VALVE 
SIZE
COPPER
TUBING
(O.D.)
IN. (MM)
3/8
1/2
1/2
5/8
3-1/16
(78)
3-3/8
(85)
7/8
(22)
1-3/16
(30)
13/16
(20)
7/8
(22)
1-1/2
(38)
1-3/4
(44)
3/8
(10)
7/16
(11)
1-1/2
(38)
1-11/16
(43)
3
(76)
3-7/16
(87)
5-3/4
(146)
6-1/4
(159)
ALLOW 1-1/2 IN. (38 MM) MINIMUM CLEARANCE FOR REMOVING 
ACTUATOR. ALLOW 2-1/2 IN. (63 MM) TO FACILITATE STRAIGHT ON 
TUBING. IF CLEARANCE IS LESS THAN 2-1/2 IN. (63 MM), USE 
AN ELBOW.
M18807A
A
AB
B
SUPPLY
RETURN
CONTROL AIR
VP526A
N. O. PORTS
B  TO  AB
C2726
COIL
C493-1
CLOSE OFF PRESSURE RATING, PSI (kPa)
(DIFFERENTIAL PRESSURE BETWEEN
SUPPLY AND RETURN LINES)
010
(69)
20
(138)
30
(207)
40
(276)
50
(345)
60
(414)
70
(483)
ALL C
V
s
5
6
7
8
9
10
11
12
13
14
10
11
12
13
14
15
16
17
18
—
2
1
0
—
—
—
—
—
—
—
3
2
1
0
—
—
—
—
—
—
11
12
13
14
15
16
17
18
—
—
8
7
6
5
4
3
2
1
0
—
BA B A BA
CONTROL AIR PRESSURE ON
ACTUATOR, PSI (kPa)
PORTS
2-5 PSI SPRING
(14-34 kPa)
3-10 PSI SPRING
(21-69 kPa)
8-11 PSI SPRING
(55-76 kPa)