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Pre-Start-Up Check and Commissioning Audit
After having loaded the elements into the pressure
vessels and before starting up the membrane unit, make sure that the whole
pretreatment section is working in accordance with the specifications. If the
pretreatment involved changing of the chemical characteristics of the raw water,
then a full analysis of the water entering the membrane unit must be made.
Furthermore, absence of chlorine, turbidity and SDI must be determined.
The raw water intake must be stable with respect to:
- Flow
- SDI
- Turbidity
- Temperature
- pH
- Conductivity
- Bacteria (standard plate count)
The following checks of the pretreatment system and the
membrane unit are recommended for the initial start-up (results to be included
in the start-up report):
| Pre-Start-Up Checklist
□Corrosion
resistant materials of construction are used for all equipment from the
supply source to the membrane including piping, vessels, instruments and
wetted parts of pumps
□ All piping and equipment is compatible with
designed pressure
□ All piping and equipment is compatible with
designed pH range (cleaning)
□ All piping and equipment is protected against
galvanic corrosion
□ Media filters are backwashed and rinsed
□ New/clean cartridge filter is installed directly
upstream of the high pressure pump
□ Feed line, including RO feed manifold, is purged
and flushed, before pressure vessels are connected
□ Chemical addition points are properly located
□ Check/anti-siphon valves are properly installed
in chemical addition lines
□ Provisions exist for proper mixing of chemicals
in the feed stream
□ Dosage chemical tanks are filled with the right
chemicals
□ Provisions exist for preventing the RO system
from operating when the dosage pumps are shut down
□ Provisions exist for preventing the dosage pumps
from operating when the RO system is shut down
□ If chlorine is used, provisions exist to ensure
complete chlorine removal prior to the membranes
□ Planned instrumentation allows proper operation
and monitoring of the pretreatment and RO system
□ Planned instrumentation is installed and
operative
□ Instrument calibration is verified
□ Pressure relief protection is installed and
correctly set
□ Provisions exist for preventing the permeate
pressure from exceeding the feed/concentrate pressure more than 5 psi
(0.3 bar) at any time
□ Interlocks, time delay relays and alarms are
properly set
□ Provisions exist for sampling permeate from
individual modules
□ Provisions exist for sampling raw water, feed,
permeate and concentrate streams from each stage and the total plant
permeate stream
□ Pressure vessels are properly piped both for
operation and cleaning mode
□ Pressure vessels are secured to the rack or
frame per manufacturer’s instructions
□ Precautions as given in Loading of Pressure
Vessels (Section 4.1 & 4.2), are taken
□ Membranes are protected from temperature
extremes (freezing, direct sunlight, heater exhaust, etc.)
□ Pumps are ready for operation: aligned,
lubricated, proper rotation
□ Fittings are tight
□ Cleaning system is installed and operative
□ Permeate line is open
□ Permeate flow is directed to drain (In
double-pass systems, provisions exist to flush first pass without
permeate going through the second pass)
□ Reject flow control valve is in open position
□ Feed flow valve is throttled and/or pump bypass
valve is partly open to limit feed flow to less than 50% of operating
feed flow |
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