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February 8, 2019 at 8:14 am #397Markus StoeckliKeymaster
The iMatrixSpray utilizes a valve to switch between the different solvents. Over time, the rotor and stator get worn down, and eventually will start leaking. This is normal for every valve and the only solution is to replace the valve. But, since this is a low-pressure valve, the cost is equally low at about 450 USD.
The valve is from Upchurch, type V-241. VWR product number EU: 560-0166, USA: 53500-826
To change the valve, follow this procedure:
- Open the cover of the device
- Localize the valve coupling housing
- Submit a G28V command
- Submit a command which puts the hex screw towards the opening (e.g. G1 V3.5, or G1 V2.4 … )
- Loosen the screw holding the valve in place using a hex key (the one facing the valve and not the one on the motor). This screw has a pointed tip which extends in the groove of the valve axis. Some designs have an additional screw which clamps the axis. This needs to be loosened too.
- IMPORTANT: Don’t submit any command when this screw is extended. This will damage the position sensor!
- Once the screw is loose, you may pull out the valve. This may require some moderate force.
- To put a new valve in place, ensure that the groove of the axis is aligned with the hex-screw (IMPORTANT).
- Push it all the way in and tighten the hex screw. If there is a clamping screw, tighten this one first.
- Test proper operation (G28V, G1 V1 …)
If you want to disassemble the valve, you need to build some mechanism to measure the rotation momentum. A proper valve needs 12 Ncm to turn. You may disassemble the valve by losing the nut at the back. IMPORTANT: This nut also controls the force on the rotor and the rotation momentum required. When disassembling, take a picture of the spring package as it needs to be re-assembled exactly the same way. Once clean, re-assemble the valve and tighten the nut to achieve the 12 Ncm (too loose will lead to leakage, too hard will prevent the motor from turning)
VERY IMPORTANT: When re-connecting the capillary, ensure that the end is flush with the fitting and does not extend. Otherwise the valve will be damaged immediately, rendering it unusable.
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