What do we need to consider? Design Installation Cleaning - PowerPoint PPT Presentation

What do we need to consider? • Design • Installation • Cleaning methodology • Water Quality at Practical Completion

Design  The system design should be reviewed to make sure that it allows good water quality to be achieved and maintained  All necessary flushing facilities are present (bypasses, flushing connections, valve arrangements etc.)  Dead legs should be avoided  Pipework materials of installation  Pressurisation units (flow through units, short connecting pipework)

Design  Dosing pots (not automated dosing)  Use of de-aerators  Use of HEX units  Water conservation in flushing  Side stream filters  The BMS needs to be considered to ensure that routine circulation through all previously wetted areas can be achieve

Installation  Clean installation practices  Wet pipework and plant as close to the start of flushing as possible  Use treated water for pressure test  Take appropriate precautions after pipework is wet  Water treatment planning to be co-ordinated with installation plan

Pipework waiting to be installed

Pipework installed

Even when racked no caps fitted

Stored on site

Installation  All points listed are common to both conventional and low effluent processes and are instrumental in the successful outcome of water treatment

Cleaning Methodology Conventional No/Low effluent  Tried and tested  Saves water and relies on filtration- but filters go to ‘land fill’  Will require significant water and  Possible time saving/ labour drainage capacity reduction  Is robust in approach  Requires consideration at the time  The long term prognosis is of design/installation understood  Chemicals added to system stay there increasing TDS and presenting other challenges  If it should fail it would be necessary to revert to conventional treatment

Use of Side Stream Filter as Flushing Aid

Water Treatment  Flushing and cleaning should be undertaken in accordance with BG 29/2012  Dynamic flushing should be correctly undertaken  Biocide washes should be employed as necessary  Chemical cleaning should be carefully monitored  Final dosing chemicals should be effective and selected with system metallurgy and components in mind  Limitations of low flow devices when backflushing

Where low flow occurs 2 port valve, kv value 0.25 (open)

Water Quality Maintenance until PC  Take first set of samples 7 days after final chemical dose. PCC samples  Routine (daily) checks that completed systems are kept full and pressurised  Routine (daily) checks that pumps are circulating and valves are in the correct position  Control over any necessary drain downs and pipework alterations  Fortnightly sampling to allow timely chemical additions as required

At PC the client should be provided with:  Stable and maintainable water in closed systems  Trend results as outlined in BSRIA 29/2012 (see next 2 slides)

The Site LTHW TVC @22˚C CFU/ml Date Geometric mean PC Guideline PCC Guideline Trend 105 100,000 10,000 01/02/2012 1 100,000 10,000 17/02/2012 1 100,000 10,000 Acceptable 01/03/2012 1 100,000 10,000 Acceptable 15/03/2012 Site - LTHW - 100000 10000 TVC Level 1000 Geometric mean 100 PC Guideline PCC Guideline 10 1 Date

The Site LTHW Secondary Pseudomonad @30˚C CFU/100 ml Date Geometric mean PC Guideline PCC Guideline Trend 412.13 10,000 1,000 01/02/2012 100 10,000 1,000 17/02/2012 Increasing trend and above PCC 2607.23 10,000 1,000 level 01/03/2012 100000 10,000 1,000 Unacceptable 15/03/2012 Site LTHW Secondary 100000.00 Pseudomonad Level 10000.00 1000.00 Geometric mean 100.00 PC Guideline 10.00 PCC Guideline 1.00 Date