KROHNE OPTIMASS with MFC 05x EN - Manual (Page 19)

Installation and Operating Instructions OPTIMASS 18
1.2.8 Purge Port Meters and Burst Disk Meters
Purge Port Options
If the purge port option was selected at time of order, then your meter will be fitted with ½” NPT female
connections – these will be clearly identified. These connections are sealed with NPT plugs and PTFE
tape.
Important:
Do not remove these plugs.
The meter is factory sealed with a dry nitrogen gas fill and any ingress of moisture will damage the meter.
The plugs should only be removed to purge the inside of the meter case of any product if it is suspected
that the primary measuring tube has failed. This must only be done after the meter has been
depressurised and removed from service. This should be done as soon as possible after failure is
suspected (less than 3 days)
Burst Disk meters (Meters up to size 25 only)
OPTIMASS 7000 meters that have been ordered with a bursting (rupture) disk will be so fitted. This is
fitted when the operating pressure of the measuring tube exceeds the design pressure of the secondary
containment. The disk failure pressure is 20bar @ 20°C.
Important:
The burst disk is suitable for the designed application according to the process conditions and flow rates
as per original order. If conditions alter, consult KROHNE for further advice regarding suitability of disk
fitted.
If the product is in any way hazardous, it is strongly recommended that an exhaust tube is connected to
the NPT male thread of the burst disk so that the discharge can be piped to a safe area. This tube should
be large enough that pressure cannot build up in the meter case.
Ensure arrow on burst disk is pointing away from meter.