9- Maintenance; Introduction; Preventive Maintenance; Inspecting And Cleaning Barrier Diaphragms - Honeywell ST 3000 User Manual

Introduction

About this section
This section provides information about preventive maintenance routines and replacing damaged parts. The
topics covered in this section are:
Preventive maintenance of the meter body barrier diaphragms and process piping to the transmitter.
Replacement of damaged parts such as the transmitter PWA and meter body.

Preventive Maintenance

Maintenance routines and schedules
The ST 3000 transmitter itself does not require any specific maintenance routine at regularly scheduled
intervals. However, you should consider carrying out these typical inspection and maintenance routines on
a schedule that is dictated by the characteristics of the process medium being measured and whether blow-
down facilities or purge systems are being used.
Check piping for leaks.
Clear the piping of sediment or other foreign matter.
Clean the transmitter's pressure chambers including the barrier diaphragms.

Inspecting and Cleaning Barrier Diaphragms

Depending on the characteristics of the process medium being measured, sediment or other foreign
particles may collect in the process head cavity/chamber and cause faulty measurement. In addition, the
barrier diaphragm or diaphragms in the transmitter's meter body may become coated with a residue from
the process medium. The latter is also true for external diaphragms on flange mount and remote seal type
transmitters.
In most cases, you can readily remove the process head or heads from the transmitter's meter body to clean
the process head cavity and inspect the barrier diaphragm or diaphragms. For flange mount and remote seal
diaphragms, you may only need to run a purge line in the tank to rinse off the face of the diaphragm.
Procedure
The procedure in Table 41 outlines the general steps for inspecting and cleaning barrier diaphragms. You
may have to modify the steps to meet your particular process or transmitter model requirements. Figure 38
shows an exploded view of a DP transmitter's meter body for reference.
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9— Maintenance
ST 3000 HART Transmitter Release 300 User Manual
9— Maintenance - Introduction
97