Edwards B424-09-000, Инструкция по эксплуатации

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B426-09-880 Issue A
Page 10 © Edwards Limited 2009. All rights reserved.
Edwards and the Edwards logo are trademarks of Edwards Limited.
MAINTENANCE
5 MAINTENANCE
5.1 General information
QSB valves are designed to require little user maintenance. The only parts which you can replace are the valve shaft
‘O’ rings and the valve plate ‘O’ ring. These have been tested in excess of 1.5 x 10
5
operations before any increased
leak rate (either across the valve or from the system to atmosphere) can be expected. Refer to Section 5.4 for the
replacement procedure. Refer to Section 7 for the Item Numbers of the ‘O’ rings.
5.2 Safety
z
Ensure that you do maintenance in a well ventilated area.
z
Observe all appropriate safety precautions when you maintain a valve from a system in which dangerous
process substances have been pumped.
z
Dispose safely of all components which have been contaminated by dangerous process substances (see
Section 6.2 ).
z
Do not use abrasive or reactive chemical substances to clean the valve. Do not use solvents to clean seals or
‘O’ rings.
z
Disconnect the pneumatic supply before you remove the valve from your vacuum system.
z
Do not operate the valve when it is disconnected from your vacuum system, unless you provide protection
against moving parts.
z
Leak test the valve after maintenance to ensure that dangerous process substances do not leak to
atmosphere.
z
The dynamic seals and ‘O’ rings used in this valve are made from a fluoroelastomer. Fluoroelastomers can
decompose into very dangerous substances if they are heated to 260 °C and above. The valve may have
overheated if your vacuum system has been misused or if it has malfunctioned. If the valve has overheated,
ensure that you prevent contact with the seals and ‘O’ rings.
5.3 Maintenance plan
The plan in Table 4 details the maintenance operations necessary to maintain the QSB valve in normal use.
Instructions for each operation are given in the section shown.
Table 4 - Maintenance plan
WARNING
Obey the safety instructions given below and take note of appropriate precautions. If you do not,
you can cause injury to people and damage to equipment.
Operation Frequency Refer to Section
Dismantle and inspect the valve Every 6 months 5.4
Replace the valve-plate ‘O’ ring As required (typically every 1 x 10
5
cycles) 5.6
Replace the valve-shaft ‘O’ ring As required (typically every 1 x 10
5
cycles) 5.7
Adjust the position indicator As required 5.8