SF.813 METHOD STATEMENT

MS No: ………………… Issue: .…A……
Project/Job No: ………..…. Name: …Template…….

Brief Description: OFN Pressure Testing

/ 
ThornliebankInd Estate, Glasgow G46 8JW
Tel: 0141 638 7916 Fax: 0141 638 8111
e-mail:

Issue

1.0 / Scope of Work / Preparation notes:
delete column before issuing.
1.1 / General Description of Works, Location & Boundaries
Strength and tightness testing of Glycol System between plant room and first cooler valve stations in roof void using Oxygen Free Nitrogen. / Example, edit as applicable
1.2 / Equipment to be Installed / Removed / Isolated
Balance lines to be install around check valves xyz (GS4 24(b))
Relief valves xyz to be removed.
Pressure Transmitters xyz to be isolated / Edit as applicable
2.0 / Dates and Times
Tests to be carried out starting 08.00 Monday 28 Nov for completion 18.00 Friday 2 Dec.
Strength tests to be carried out at times when areas can be clear of all personnel. / Edit (times &) dates
Identify specific time if applicable
3.0 / Monitoring and Witnessing
The competent person in charge of the test must be present during initial pressurising of the system, whilst the system is being raised to and held at strength test pressure and until the system pressure has been reduced in pressure for examination.
The pressure source must not be left unattended while not isolated from the system.
The customer (Mr Everright, tel 01234-56789) to be notified 15 minutes before system is expected to reach strength test pressure. Test duration is NOT to be extended to await his arrival.
The customer (Mr Everright, tel 01234-56789) to be notified when system reaches Maximum Allowable Pressure. The system is not to be raised to full strength test pressure until the customer is present or has given his consent for the test to proceed. / A normal requirement
Examples only – edit/delete as applicable
4.0 / Resources / Sections 6 to 12 should be used before completing Sections 4 and 5
4.1 / Supervision, Labour, Qualifications and Training
Engineer - Gary Carpenter – Star pressure test trained Oct 05
Second Man – Joe Brown–Star ST1 Engineer
4.2 / Tools and Equipment to be used, Certification and Notes
OFN Pack(s)
Pressure test manifold – from London branch
Test hoses – Ammonia charging hose tested 09/12/04
- 6mm st.st. tube and fittings
Regulator – 230 to 40 bar
Safety valve (see SS125 Sect 3.0) – 10 bar
Calibrated gauge – B9018455-04-018, calibrated 29/9/05
Torches
Soapy bubble solution with containers, paint brushes and/or sprayer.
Barrier tape and pressure test warning signs. / Note: Regulation 40 bar outlet except for CO2
Note: Gauge workings within 20% - 80% range
4.3 / Personal Protective Equipment
The following PPE will be worn at all times: Safety Boots, Overalls, Safety Helmet. Flame Retarded High Visibility Vest.
The following PPE will be worn at appropriate stages in the operation as detailed in the Relevant Documents in section 11: Gloves, Hearing Protection, Safety Harness, Eye Protection. / Fairly standard requirements
5.0 / Detailed Sequence/Method of Working
Engineer and second man to initial each section as test proceeds / Eng.
Inits. / 2nd
Man
Inits / Preparation notes:
delete column before issuing.
5.1 / Confirm test pressures from diagram of connections:
Initial Examination (max 10% MAP) – 0.8 bar
Maximum Allowable Pressure – 8.0 bar
Strength Test – 8.8 bar
Tightness Test – 8.0 bar / Edit pressures as applicable.
5.2 / Prepare System Pressure Test Record SF.052 - identifying extent of test and components to be included in or isolated from test. Refer to SS113 for further guidance.
5.3 / Confirm that all vessels have previously been (hydraulically) strength tested to a pressure higher than the current OFN strength test pressure.
5.4 / Inform the customer that a pressure test is to take place and the restrictions which will apply.
Confirm what witnessing, if any, they require – see 3.0.
5.5 / Survey the system and identify the exclusion area (see 7.1) – typically people must be kept outside the building or a minimum of 30 meters from the components under test. (SS 125 Sect 5.4. and GS4 27(b)) / Edit if necessary e.g. refer to appended sketch of exclusion area
5.6 / Identify a safe working area for setting up the test equipment – typically behind a brick wall and out of line of site to condensers, pipework or other components under test. / Refer to sketch if applicable
5.7 / Establish a safe means of discharging nitrogen to atmosphere (not a confined space) without entering the exclusion area.
5.8 / Check system for tightness.
5.9 / Confirm that applicable valves are open or closed.
5.10 / Confirm that applicable items are isolated or removed for the test e.g. relief valves (see 1.2).
5.11 / Confirm and balance lines are installed around check valves as required (see 1.2).
5.12 / Confirm all systems, vessels, etc. connected to section under test are vented to prevent pressure build up should isolation valves pass.
5.13 / Set up test equipment in safe area.
5.14 / Confirm correct regulator is fitted (230 bar or 300bar).
5.15 / Confirm correct calibrated gauge (20% to 80% of range) is fitted.
5.16 / Confirm correct safety relief valve is fitted (see 5.1) and is correctly located in accordance with SS125.
5.17 / Secure any single OFN cylinders in a vertical position and restrain charging line with tie wraps or equivalent.
5.18 / Confirm correct PPE is being worn (see 4.3)
5.19 / Set regulator outlet pressure to not more than 10 bar above initial examination pressure (see 5.1)
5.20 / Gradually introduce nitrogen into the system until the initial examination pressure is reached (see 5.1). Isolate the system from the nitrogen supply.
NEVER LEAVE THE PRESSURE SOURCE UNATTENDED WHILE OPEN TO THE SYSTEM UNDER TEST.
5.21 / Enter exclusion area and carry out a visual /aural inspection of the system for obvious leaks. If necessary use a soapy bubble test to pinpoint leaks.
5.22 / If any repairs are required, isolate as applicable and reduce that section of the system to atmospheric pressure before proceeding.
5.23 / Repeat steps 5.15 to 5.17 until all obvious leaks have been repaired.
5.24 / Cordon off exclusion area, place signs prohibiting access and ensure all personnel have left. / If known, the location of cordons and signs can be detailed here.
5.25 / Set regulator outlet pressure to not more than 5 bar above strength test pressure (see 5.1)
5.26 / From the safe area, slowly introduce the nitrogen into the system until the strength test pressure (see 5.1) is reached.
NEVER LEAVE THE PRESSURE SOURCE UNATTENDED WHILE OPEN TO THE SYSTEM UNDER TEST.
CAUTION:
No-one may approach the system during this phase unless the following procedure is followed:
a)Isolate the system from the nitrogen supply.
b)Working from within the safe area, reduce the system pressure by at least 1 bar or 10%, whichever is the larger.
c)The system may now be approached.
d)If any leaking flanged joints and screwed fittings require tightened or if any other repair is required, that section of the system must be isolated and reduced to atmospheric pressure before proceeding with the repairs. A safe means of discharging nitrogen to atmosphere must be used.
e)After repairs, slowly re-introduce nitrogen into the vented section.
f)From the safe area, proceed with the strength test. / Add customer witness note if applicable.
5.27 / When the strength test pressure is reached, isolate the system from the nitrogen supply and hold the strength test pressure for 5 minutes. / Add customer witness note if applicable.
5.28 / Reduce the pressure in the system tightness test pressure (see 5.1) and hold for the duration of the tightness test.
At this stage general access restrictions can be lifted, signs removed and the system can be approached.
5.29 / Leave the plant to stand under pressure for at least 30 minutes, monitoring the gauge for a fall in pressure which might indicate a leak (the drop test).
During the drop test, or later as convenient, test for leaks using soapy bubble solution.
REPAIRS
a)If any leaking flanged joints and screwed fittings require tightened or if any other repair is required, that section of the system must be isolated and reduced to atmospheric pressure before proceeding with the repairs. A safe means of discharging nitrogen to atmosphere must be used
b)After repairs, slowly re-introduce nitrogen into the vented section.
c)Bring the system back up to tightness test pressure (see 5.1) with additional nitrogen if required
d)If the leak repairs involved cutting or welding of the pressure envelope, repeat the strength test.
e)Repeat the drop test – 5.24.
f)Repeat the soapy bubble test on the repairs only. / Add customer witness note if applicable.
Add Helium sniffer if applicable
5.30 / Reduce the pressure in the system to atmospheric. / Or perhaps a 0.5 bar holding charge
5.31 / Confirm that there is no trapped pressure in the system e.g. behind check valves.
5.32 / Inform customer that the tests are complete.
5.33 / Dismantle test equipment and return it to store.
5.34 / Replace items removed for pressure test (see 1.2).
5.35 / Complete the System Pressure Test Record (SF.052).

Revision

Issue / Revision Notes* / Name (print) / Signature / Date
A / First Issue

Distribution

I confirm that I have read and understood this Method Statement and the associated Risk Assessment(s) and COSHH Safety Data Sheet(s).

Should circumstances change which invalidate this Method Statement or prevent the Control Measures being implemented, work shall be suspended until the Method Statement has been reviewed by the author or other suitable, competent, person and, if necessary, revised.

MS Issue / Name (print) / Signature / Company / Date

Method Statement Preparation Checklist and Additional Notes – use before completing Sections 4 and 5 above

6.0 / Tools and Equipment to be used, Certification and Notes
6.1 / Lifting Equipment
Plant Room lifting beam to be used for lifting OFN cylinders into plant room. Hoist certificates held in site office / Example only
6.2 / Access Equipment
Mobile scaffold tower and ladders to be used for access to leak test welds and fittings as required. Inspections per general site routine. / Example only
6.3 / Vehicles and Plant
Not applicable / Edit if required
6.4 / Portable Equipment
Certification (see section 4.2 for listing) to be held in site office:
  • Pressure test manifold
  • Test hoses
  • Regulator
  • Safety valve
  • Gauge
/ Confirm certificates available
7.0 / Summary of Control Measures
See Relevant Document referenced in section 11 for full details
7.1 / Permits/Access restrictions/Signs
See attached sketch reference Appendix 1 for details of exclusion area. / Examples only
7.2 / Access and Lighting
Access to plant room via staircase
Temporary lighting available in Plant room
Torches available to supplement / Examples only
7.3 / Storage and Disposal of Materials
Nitrogen packs to be stored in caged compound when not in use.
Nitrogen to be released to atmosphere after use / Edit if caged compound is not available.
7.5 / Information/Action by Customer
Customer to observe and co-operate with exclusion areas during strength test
8.0 / Emergency Arrangement
As site procedure detailed at induction
8.1 / First Aid
First aid kit available in Star site office / Add details of any site first aid facility
8.2 / Fire
No significant risk. / Modify if not so
8.3 / Chemical Leaks
No significant risk / Modify if not so
8.4 / Incident Reporting
Any incidents or near misses to be reported to Star Site Manager and the Main Contractor/Customer – Form SF 807 to be completed for a near miss.
9.0 /
Temporarily Amended Systems
9.1 / Plant Isolation and Alterations
Not Applicable / Confirm?
9.2 / Traffic Routing
Not Applicable / Or insert details of rerouting of vehicular and personnel traffic
10.0 / Statutory Records
Not Applicable
11.0 / Relevant Documents
11.1 / Risk Assessments
RA - 003 – OFN pressure testing of package unit piping, site pipe work & pre-fabricated pipe and component assemblies – copy available in the Star site office. / If library risk assessment is not applicable a site specific one will be required.
Confirm copy is held on site.
11.2 / Material Safety Data Sheets
Oxygen Free Nitrogen – copy available in Star site office / Confirm copy is held on site.
11.3 / COSHH Assessment
COSHH A.016 Oxygen Free Nitrogen & 90-10 OFN-Helium – copy available in Star site office / Confirm copy held on site.
11.4 / Star Standard Specifications and Technical Bulletins
Standard Specification No. 125 – Pressure Test Procedures – copy available in Star site office
Standard Specification No. 113 – Pressure Test Certification of Systems – copy available in Star site office / Confirm copy is held on site.
11.5 / Drawings
Insert DoC drawing Nos
11.6 / Other
Not Applicable
12.0 /
Additional Information
12.1 / Add site specific additional info.
12.2
12.3

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