Cameron BARTON 289A - Page 66

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Model 199 Differential Pressure Unit (DPU) Section 4
Table 4.3—Troubleshooting Chart
Trouble
Possible Source
Probable Cause
Corrective Action
High
Indication
Primary Orice partially restricted
or too small
Clean out or replace
Piping from
Primary Element
to DPU
Leak in LP side piping Repair leaks
Bellows Unit Gas trapped (liquid
service) in LP housing or
liquid trapped (gas ser-
vice) in HP housing
Vent housing
LP housing gasket leaks Replace gasket
Range spring broken or
DPU tampered with
Return BUA for
repair
Mechanism Loose links or movements Repair or replace
Out of calibration Calibrate
Erratic
Indication
Primary Flow pulsating Install dampening
device upstream of
DPU run
Piping from
Primary Element
to DPU
Liquid trapped in gas
piping or gas bubble in
liquid piping
Remove (see
Startup Procedure,
Section 3)
Vapor generator incor-
rectly installed
Repipe
Reference leg gassy or
liquid vaporizing
See piping instruc-
tions
Bellows Unit Obstructed bellows travel Clean bellows
Gas trapped in DPU HP or
LP housing
Remove (see
Startup Procedure,
Section 3)
Mechanism Linkage dragging or dirty Adjust or clean
Pointer dragging on scale
plate
Adjust