September 2019
Installation, Operation and Maintenance Manual
MAN720_IMVS2000v2_IOM Rev. 6
MAN720_IMVS2000v2_IOM Rev. 6
Section 5: Working Principle
Working Principle
The Manual PST allows recording the times and pressures of the partial opening stroke or of the partial
closing stroke; these values are compared with the ones of the Baseline PST and if they overtake the set
tolerances, dedicated alarm are generated (see Sections 5.2.7, 8 and 5.1.9 for details).
The Baseline PST and the Manual PST can be launched by the following interfaces:
• Local Operator Interface
• Biffi Assistant (Bluetooth and RS232)
• Bus Interface
• “PST Control” Digital Input (only for Manual PST)
To take the full operational capability of the IMVS2 at its own best, it is suggested to perform the
Baseline and Manual PSTs in the following conditions:
• pressures and position stable.
• valve in its “normal” working position (e.g. Open position for a “fail to close” actuator)
5.1.5 SOVs Test
The IMVS2000v2 can control up two external SOVs with independent and isolated circuits.
The IMVS2000v2 can perform the SOV test to check the SOV integrity if:
- A single SOV is present
- Two SOVs are connected in series
See 6.2 for details.
The SOV test consists of managing one or two SOVs to generate a pressure decrease inside the
cylinder (detected by pressure sensor) without generating the actuator movement
There are four possible configurations (see 6 for details):
1. Configuration X
• “Act. Mode” = “Single” or “Double-S”
• “SOVs Qty” = “Series”
• “PST Ser. SOVs” = “Both”
• “Pr. S. 1-2” ≠ “None”
• “PST En.” = “Yes”
The SOV test is executed during the PST command (see 5.1.9.1 for details). The two SOVs are involved
in all the command of the IMVS2000v2 (Calibration, Signatures and PST).
2. Configuration Y
• “Act. Mode” = “Single” or “Double-S”
• “SOVs Qty” = “Simplex”
• “PST Ser. SOVs” = “Both”
• “Pr. S. 1-2” ≠ “None”
• “PST En.” = “Yes”
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