Starting Maintenance - Honeywell HON 5020 User And Maintenance Manual

8.3

Starting maintenance

Pressurized parts
Overview
Establishing the depres-
surized status
Purging the lines with
nitrogen
HON 5020 gas pressure regulator with HON 630 pilot
Risk of serious injury posed by pressurized components moving in an uncontrolled manner
when handled improperly.
If not handled properly or in the event of a defect, gas can escape from pressurized compo-
nents under high pressure and cause serious injuries and even death. Before you start work-
ing on these components:
 Close all connections leading to the gas-carrying line.
 Establish a depressurized status. Residual amounts of energy must be depressurized as
well.
Schematic diagram using the two-stage HON 630 pilot with a diaphragm assembly as a
reference
The numbers have the following meaning:
No. Meaning
1 Inlet stop valve armature
2 Gas pressure regulator
3 Pressure gauge
4 Outlet stop valve armature
5 Valve for blowdown line
6 Blowdown line
Proceed as follows:
Step Description
1 Close the outlet stop valve armature (4).
2 Close the inlet stop valve armature (1).
3 Depressurize the pilot:
Turn the set screw on the pilot's control stage – and the set screw on the pilot's load
limiting stage as well if applicable – clockwise until the pressure in the pilot is equalized.
4 Open the valve (5) in the blowdown line (6) to discharge the pressure between the inlet
and the outlet valves.
All the gas pressure regulator's lines must be purged with nitrogen before the device is re-
moved.
Maintenance
47