76
8.2.2 Air regulators
For correct and fault free functioning of pneumatic components it is advised to regularly check and
drain the regulator housing of excess water. If a great deal of water is found, the filter in the
regulator house should be replaced. Also a check should then be performed on the ship’s control air
system, compressors, air-dryers etc.
8.2.3 Cleaning the detector cell windows
Drawing 0806-1279 shows the detector cell and will help to visualize the following.
NOTE:
The internal parts of the detector cell have been chemically treated. it is important to
ensure that the coating remains intact and that no bare metal has been exposed.
Cleaning of the detector cell is normally not required but in cases where repeated failure of the
system to qualify occurs, the following cleaning procedure can be undertaken:
1. Relieve any pressure from the cell body.
2. Remove the upper pipe clamp above the cell.
3. Remove mounting bolts of the flow regulator.
4. Unscrew the upper coupling on flow sensor.
5. Unscrew the four upper hex drive bolts.
6. Remove the upper connection piece of the measurement cell and slide out to the front of the
skid assembly.
7. The inner parts of the cell can now be cleaned by using the cleansing brush (part number
0609-0290) provided.
8. Re-assembly of the cell is the reverse procedure, taking care that the O-ring is properly
seated.
8.2.4 Window wash pump
No maintenance on this unit is envisioned. Should the unit fail to operate, repairs can be carried out
as described in section 9.2.
8.2.5 Skid shuttle valve
No maintenance on this unit is envisioned. Should the unit fail to operate, a replacement unit should
be installed. If any water leakage through the end cap bleed holes is detected, the assembly should
be delivered to a qualified VAF Instruments service point for overhaul.
8.2.6 2-Way pneumatic valve(s)
No maintenance on this unit is envisioned. Should the unit fail to operate, a replacement unit should
be installed. If any water leakage through the end cap bleed holes is detected, the assembly should
be delivered to a qualified VAF Instruments service point for overhaul.
8.2.7 Zero output check of the differential pressure transmitter
1. Open equalising valve of DPT.
2. The FLOW indication on the MCU should now read zero. If reading is not zero, adjust zero
point at DPT, in accordance with section 9.4.1, until reading is zero.
3. Close equalising valve of DPT.
To Next Page
Loading...