Emerson Fisher 92B, Инструкция по эксплуатации, Страница: 5 / 24

1. Inspect the Type 92B for any shipment damage.
Remove any foreign materials that may have collected
in the valve during shipment.
2. Blow down the pipeline as required.
3. Install a strainer ahead of the Type 92B to protect the
internal parts of the valve.
4. Install an upstream block valve ahead of the Type 92B
and a downstream block valve, if required, so that
the valve can be isolated and serviced. If continuous
operation is necessary during maintenance or
inspection, install bypass piping and valve around the
Type 92B.
5. This Type 92B is intended to be installed with
the diaphragm case above the pipeline so that
condensate will not collect in the case.
6. Install the Type 92B in the pipeline so that the flow
will be in the direction indicated by the arrow cast
on the body. Follow normal piping procedures when
installing the screwed or flanged control valve.
7. Install the external control line as follows:
a. Connect one end of the control line to the
Type 92B body tapping. This tapping is
1/4 NPT for NPS 1 and 2 / DN 25 and 40
bodies, 3/8 NPT for NPS 2 / DN 50 body and
1/2 NPT for NPS 3 and 4 / DN 80 and
100 bodies.
Table 4.
Minimum Differential Pressures for Safety Override System
TYPE
SPRING RANGE
SPRING COLOR
MINIMUM PRESSURE AT WHICH MONITORING
PILOT CAN BE SET, psig / bar
psig bar
6492HM
10 to 30 0.69 to 2.1 Yellow 10 / 0.69 over normal downstream pressure
25 to 75 1.7 to 5.17 Green 10 / 0.69 over normal downstream pressure
70 to 150 4.8 to 10.3 Red 15 / 1.0 over normal downstream pressure
6492HTM
15 to 100 1.0 to 6.9 Unpainted 10 / 0.69 over normal downstream pressure
80 to 250 5.5 to 17.2 Unpainted 25 / 1.7 over normal downstream pressure
TYPE 92B PILOT (B) TYPE 92B PILOT (C)
TYPE 92B MAIN VALVE TYPE 92B MAIN VALVE
TYPE 6492HM SAFETY
OVERRIDE PILOT (A)
INLET PRESSURE
OUTLET PRESSURE
ATMOSPHERIC PRESSURE
LOADING PRESSURE
INTERMEDIATE PRESSURE
E0794
Figure 3.
Safety Override System Schematic
5
Type 92B