Yokogawa RAGN - Manual (Page 41)

<A1. SAFETY INSTRUMENTED SYSTEMS INSTALLATION>
A1-1
IM 01R01B10-00E-E 2nd edition: November 01, 2011-00 All Rights Reserved. Copyright © 2011, Rota Yokogawa
The contents of this appendix are cited from exida.com safety manual on the Rotameter RAGN Flowmeter
specifically observed for the safety transmitter purpose. When using the RAGN for Safety Instrumented
Systems (SIS) application, the instructions and procedures in this section must be strictly followed in order
to preserve the meter for that safety level.
A1.1 Scope and Purpose
This document provides an overview of the user responsibilities for installation and operation of the Rota
Yokogawa RAGN variable area flow meter, herein referred to as RAGN Glass Rotameter, in order to maintain
the designed safety level. Items that will be addressed are proof testing, repair and replacement of the flow
meter, reliability data, lifetime, environmental and application limits, and parameter settings.
A1.2 Using RAGN for a SIS Application
A1.2.1 Safety Function
Suitable for use in Safety Instrumented Systems are the versions listed in table 1 only. The safety related data
listed in this manual does not apply to other versions of RAGN.
Table 1 Versions of RAGN suitable for Safety Instrumented Systems
[V1] RAGN with Reed-switch(es)
[V2] RAGN with Ring Initiator, fail-safe state: LOW
[V3] RAGN with Ring Initiator, fail-safe state: HIGH
This variable area flow meter is intended for use as a volume flow monitoring component in a Safety
Instrumented System. It has either inductive ring sensors [V2], [V3] or magnetic reed contacts [V1] to indicate
limits. The flow meter may be used with the limit switches to feed signals to a logic solver that is part of the
safety instrumented function (SIF) as shown in Figure 1. The fault annunciation mechanism is a trip of one
of the limit switches. In order to take credit for the automatic diagnostics in the flow meter, this annunciation
mechanism must be connected.
Any valve delivered together with RAGN Glass Rotameter is not covered by the assessment.
Figure 1 Example Safety Instrumented Function
APPENDIX 1. Safety Instrumented
Systems Installation
WARNING