Emerson Fisher 634 Instructional Manual page 4

Types 634 and 634M
inleT PreSSure To
TyPe 634M SHuToff
ValVe, psig
A3328
Type 634 Shutoff Valve
psig bar
20 to 28 1.4 to 1.9
50 to 60 3.4 to 4.1
72 to 88 5.0 to 6.1
if using pipe in the following step, apply
pipe compound to the pipe threads
before making the connections.
8. Install tubing or piping into the 3/4 or 1 NPT
connections of the body. With a Type 634M shutoff
valve, also install a control line into the 1/4 NPT
control line connection in the body.
a closed Type 634 or 634M shutoff
valve means some other component
in the system, such as a reducing
regulator, is causing overpressure.
4
fraCTure diSk SHaTTer PreSSure To
TyPe 634M SHuToff ValVe, bar
0
1500
1250
1000
750
a
500
250
0
0
fraCTure diSk SHaTTer PreSSure
of TyPe 634M SHuToff ValVe, psig
Figure 5. Fracture Disk Selection
Table 1. Fracture Disk Selection
SHaTTer PreSSure
Type 634M Shutoff Valve
20 to 28 psig / 1.4 to 1.9 bar at 0 psig / 0 bar inlet
pressure; see curve A for other inlet pressures
50 to 60 psig / 3.4 to 4.1 bar at 0 psig / 0 bar inlet
pressure; see curve B for other inlet pressures
72 to 88 psig / 5.0 to 6.1 bar at 0 psig / 0 bar inlet
pressure; see curve C for other inlet pressures
note
CauTion
5
b C
25 50 75 100
The malfunctioning component and
the overpressure condition must be
corrected before the fracture disk
is replaced.
9. The downstream pressure at which the fracture
disk shatters depends on the unbalance between
inlet and downstream pressure and can be
determined from Figure 5. This shatter pressure
is non-adjustable and can only be changed if the
disk is changed (Type 634) or if either the disk or
inlet pressure is changed (Type 634M). Fracture
disks (key 4) are color coded to indicate their
shatter pressure.
10. The Type 634 shutoff valve has negligible
unbalance because downstream pressure is
essentially the same as inlet pressure during
7
103
100
75
inleT PreSSure To
TyPe 634M SHuToff
50
ValVe, bar
25
0
fraCTure diSk
Color Code
Red
Yellow
White
Part number
29A1936X012
29A1936X022
29A1936X032