Data Sheet

Bulletin 71.1:Y690A
3
INLET PRESSURE
OUTLET PRESSURE
ATMOSPHERIC PRESSURE
B2625
Figure 2. Y690A Series Operational Schematic
SLIDING PUSHER POST
OVERPRESSURE SPRING
VALVE STEM
LEVER
DOWNSTREAM
CONTROL LINE FOR
TYPES Y690AM
AND Y690AHM
VALVE DISK
PITOT TUBE FOR
TYPES Y690A
AND Y690AH
Table 4. Maximum Operating Inlet Pressures
ORIFICE
SIZE
OUTLET PRESSURE RANGE
Types Y690A and Y690AM Types Y690AH and Y690AM
Inches mm
1 to
2.5-inches w.c. /
2.5 to 6.2 mbar
2.5 to
7-inches w.c. /
6.2 to 17 mbar
5 to
10-inches w.c. /
12 to 25 mbar
7 to
16-inches w.c. /
17 to 40 mbar
15-inches w.c.
to 1.2 psig /
37 to 83 mbar
1.2 to 2.5 psig /
83 to 172 mbar
2.5 to 4.5 psig /
0.17 to 0.31 bar
4.5 to 7 psig /
0.31 to 0.48 bar
psig bar psig bar psig bar psig bar psig bar psig bar psig bar psig bar
1/8 3.2 150 10.3 150 10.3 150 10.3 150 10.3 150 10.3 150 10.3 150 10.3 150 10.3
1/4
3/8
6.4
9.5
40
20
2.8
1.4
60
20
4.1
1.4
75
35
5.2
2.4
75
35
5.2
2.4
75
35
5.2
2.4
150
60
10.3
4.1
150
60
10.3
4.1
150
60
10.3
4.1
1/2
9/16
13
14
10
5
0.69
0.34
10
5
0.69
0.34
8
5
0.55
0.34
8
5
0.55
0.34
8
5
0.55
0.34
10
6
0.69
0.41
12
8
0.83
0.55
12
8
0.83
0.55
Principle of Operation
Refer to Figure 2. When downstream demand decreases,
the pressure under the diaphragm increases. This pressure
overcomes the regulator setting (which is set by a spring).
Through the action of the sliding pusher post assembly, lever,
and valve stem the valve disk moves closer to the orice
and reduces gas ow. If demand downstream increases,
pressure under the diaphragm decreases. Spring force
pushes the pusher post assembly downward, the valve disk
moves away from the orice, and the gas ow increases.
Product Description
Y690A Series Pressure Reducing Regulators
Very low-pressure (Types Y690A and Y690AM) and higher-
pressure versions (Types Y690AH and Y690AHM) are
available for operating inlet pressures to 150 psig / 10.3 bar
and outlet pressures settings from 1-inch w.c. to 7 psig /
2.5 mbar to 0.5 bar. Refer to Table 5 for outlet pressure
ranges of each type. These regulators are available in
NPS 3/4 and 1 / DN 20 and 25 body sizes with the end
connections as shown in Table 1.
Downstream Control Line
The Types Y690AM and Y690AHM regulators have a
blocked throat stem seal with O-rings and a 1/2 NPT
control line connection in the diaphragm case. It is used
for monitoring applications or other applications where
additional equipment is installed between the regulator and
the pressure control point. The stem seal separates the
body outlet pressure from the diaphragm case.
Sliding Pusher Post
The diaphragm assembly of the regulator is equipped with
a sliding pusher post. During an overpressure situation
(outlet pressure above setpoint or lockup pressure), the
spring of the sliding pusher post is compressed, allowing the
diaphragm head to come to rest on the spring case. This
action prevents any damage to internal parts.