Data Sheet

Bulletin 71.1:CS800
10
Principle of Operation and
Overpressure Protection
Types CS800, CS820 and CS850
Base Regulator Operation
Refer to Figures 3 and 4. When downstream demand
decreases, the pressure under the diaphragm
increases. This pressure overcomes the regulator
setting (which is set by the regulator control spring).
Through the action of the 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 downstream as the
regulator opens in response to the decreased pressure
underneath the diaphragm.
Relief Operation
Internal Relief “R”
Type numbers with the “R” sufx, e.g.,
Type CS800IR, provide internal relief discharge
through the diaphragm assembly (see Figure 3) to
minimize overpressure. Any outlet pressure above
the start- to- discharge point of the non-adjustable
relief spring (see Table 5) moves the diaphragm off
the relief seat, allowing excess pressure to discharge
through the vent. If conditions should exist that
prevent normal operation of the regulator or internal
relief valve, the relief valve stem acts as a secondary
travel stop contacting the underside of the closing
cap and stopping the upward travel of the relief seat.
Since the diaphragm continues to rise as downstream
pressure builds, the diaphragm lifts off of the relief
seat to provide relief operation. This secondary
travel stop for internal relief is not available on token
relieving units. Units with internal relief valve have
1 NPT vent size. See Figures 9, 11, 13, 15, 17 and 19
for relief capacity.
High-Capacity Internal Relief “Q”
Type numbers with the “Q” sufx, e.g., Type CS800IQ,
provide high capacity relief discharge across the
diaphragm assembly to minimize overpressure. Any
outlet pressure above the start-to-discharge point of
the non-adjustable relief spring (see Table 5) moves
the diaphragm off the relief seat, allowing excess
pressure to discharge through the vent. If emergency
conditions should exist that prevent normal operation
of the regulator or internal relief valve, the relief valve
stem acts as a secondary travel stop contacting the
underside of the closing cap and stopping the upward
Table 13. Regulator and Slam-Shut Underpressure Shutoff (UPSO) Pressure and Overpressure Shutoff (OPSO) Ranges
REGULATOR
SLAM-SHUT DEVICE
Under Pressure Shut-off (UPSO) Over Pressure Shut-off (OPSO)
Type
Factory
Setpoint
Spring Range
Factory
Setpoint
(1)
Spring Range
Spring Part
Number and
Color
Factory
Setpoint
(2)
Spring Range
Over UPSO
Setpoint
(3)
Spring Part
Number and
Color
In. w.c. mbar In. w.c. mbar In. w.c. mbar In. w.c. mbar In. w.c. mbar In. w.c. mbar
CS804
7 17 5.5 to 8.5
14 to
21
3 7
2 to 12 5 to 30
T14168T0012 /
White
22 55
17 to 28 42 to 69
GF02168X012 /
Brown
11 27 8 to 12
20 to
30
6 15 25 62
14 35 10 to 16
25 to
40
9 22 30 75
1 psig 69 14 to 30
35 to
75
0.5 psig 35
0.36 to
2.3 psig
25 to
160
T14170T0012 /
Silver
2 psig 138
1.3 to
3.1 psig
90 to
214
GF02170X012 /
Orange
CS824
2 psig 138
1 to
2.5 psig
69 to
170
1 psig 69
0.36 to
2.3 psig
25 to
160
T14170T0012 /
Silver
3.5 psig 241
1.3 to
3.1 psig
90 to
214
GF02170X012 /
Orange
3 psig 207
1.5 to
3.5 psig
100 to
241
1.75 psig 121
1.5 to
7.3 psig
100 to
500
FA142869X12 /
Orange Stripe
5 psig 345
2.7 to
5.5 psig
186 to
379
GF02171X012 /
Pink
5 psig 345
2.5 to
5.5 psig
170 to
380
3 psig 207 7 psig 483
CS854 7 psig 483
5 to
10 psig
345 to
690
3.5 psig 241
1.5 to
7.3 psig
100 to
500
FA142869X12 /
Orange Stripe
9 psig 621
2.7 to
5.5 psig
186 to
379
GF02171X012 /
Pink
1. If Non-Factory UPSO setpoints are specied, a minimum differential of 4 in. w.c. / 10 mbar between UPSO setpoint and regulator setpoint must be maintained in order to ensure a
secure latch of the Slam-Shut.
2. For units equipped with Token Relief, if Non-Factory Slam-shut OPSO setpoints are specied, they must be higher than the Token Relief Start-to-Discharge values provided in Table 5.
3. If Non-Factory OPSO setpoints are specied, the allowable OPSO setpoint cannot exceed the maximum of 3 psig / 207 mbar above the regulator setpoint in order to ensure no internal
parts damage from overpressure.