Explora FDG-4 Troubleshooting

Chuck Rector

August 01, 2011

Troubleshooting the two most common faults with the Explora FDG-4 Chemistry Module

Two Most Common Faults:

1. Failed PIT (Reaction Vessel PIT and Trap Column PIT)2. Low Volume Additions (Vacuum Add Water, Vacuum Add ACN, Pump

Add Water)

Definitions:

PIT = Pressure Integrity Test

MVP = Modular Valve Positioner

Plumbing Schematic

Reaction Vessel PIT

Pressure Integrity Test of the Reaction Vessel

-- Pressure the Reaction Vessel and associated tubing with pressurized nitrogen

-- Close nitrogen supply and “isolation valves” and the system must hold pressure (minimum of 30 seconds & >200kPa)

Simplified Plumbing DiagramReaction Vessel PIT

V8

V14

V3V6

V15V16

V7

MVP2 MVP1

N2 In

N2 cross-connect (4-way)

N2 manifold (5-way)

Pressure Transducer

Vent Trap

Reaction Vessel

Dip Tube

CLOSEDOPEN OPEN

CLOSED CLOSED

CLOSEDCLOSED

V8

V14

V3V6

V15V16

V7

MVP2 MVP1

N2 In

N2 cross-connect (4-way)

N2 manifold (5-way)

Pressure Transducer

Vent Trap

Reaction Vessel

Dip Tube

CLOSEDOPEN OPEN

CLOSED CLOSED

CLOSEDCLOSED

V14

V15V16Pressure Transducer

Vent Trap

Reaction Vessel

Dip Tube

CLOSEDOPEN

CLOSED

Check the following:

• N2 supply pressure• Rx Vessel cap, including o-ring & tubing• Vent Trap cap, including o-ring & tubing• Entire path for leaks (snoop)

Pump Addition

-- Micro Pump (Lee Pump) is used to add Kryptofix solution to the Reaction Vessel

-- While the pump itself is only used to add K-222, the other aqueous reagents (H2O and HCl) are added thru the pump (using vacuum system)

-- For this reason, we can check the operation of the Lee Pump using water

-- Additions are checked by taring an empty vessel, performing an add, and weighing the vessel

Reaction Vessel

MVP5 MVP4 MVP6 MVP7

V14

H2O

MVP1

Lee Pump

Low Pump Addition Troubleshooting

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