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

• f 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

• utcome of water treatment

Cleaning Methodology

Conventional No/Low effluent

 Tried and tested  Will require significant water and

drainage capacity

 Is robust in approach  The long term prognosis is

understood

 Saves water and relies on filtration-

but filters go to ‘land fill’

 Possible time saving/ labour

reduction

 Requires consideration at the time

• f design/installation

 Chemicals added to system stay

there increasing TDS and presenting

• ther 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 01/02/2012 105 100,000 10,000 17/02/2012 1 100,000 10,000 01/03/2012 1 100,000 10,000 Acceptable 15/03/2012 1 100,000 10,000 Acceptable

1 10 100 1000 10000 100000

TVC Level

Date

Site - LTHW -

Geometric mean PC Guideline PCC Guideline

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

1.00 10.00 100.00 1000.00 10000.00 100000.00

Pseudomonad Level

Date

Site LTHW Secondary

Geometric mean PC Guideline PCC Guideline