PROCEDURE FOR RESTORING GAS SUPPLIES

KU/Gas/4

1. General In a supply emergency every effort will be made to maintain positive gas pressures in the system. Initially (and if there is time) individual consumers will be turned off at the ECV’s and pressures maintained at or above 19mb. If however gas pressures fall to zero they will be restored by following this procedure. The procedure is based on IGE/UP/1 Edition 2 and is designed to ensure supplies can be restored safely and as quickly as possible. It assumes the University plans/records and meter information are accurate. During this procedure it is important to keep all affected gas consumers advised by carrying out a mail shot informing them of the procedure, the likely duration and instructing them to ring the Cadent Gas emergency service and the University security office if they smell gas. It is proposed to test this procedure by carrying out an annual mock exercise. Despite this, should the need for the procedure arise, it is likely that the person in charge will have to use judgement and discretion when following the procedure. The volume of gas vented shall be kept to a minimum. The pressure created during the purge shall not exceed the MOP of the network. 2. Planning The system is divided into 6 discrete Meter Zones (MZ’s): MZ 1 – Meter No G1 Clock House main meter Decommissioned MZ 3 - Meter No G3 Main Campus* MZ5 and MZ6 Legally transferred to a third-party entity MZ 7 – Meter No G 340 Barnes W/X MZ 8 – Meter No G 360 Barnes *MZ 3 is by far the largest meter zone and has been divided into 3 sectors for tightness testing and purging operations. Plans showing the pipe layout for each MZ are referenced in Appendix 1 of Keele University Gas Safety Case Document Reference HS0010. The following parameters have been determined for each MZ: Volume (V) Tightness Test Pressure (TTP) Tightness Test Duration (TTD) - using the formula 0.047(GRM) x V x 67) and a water gauge with a Gauge Readable Movement (GRM) of 0.5mb (or for MZ 4 –MP system an electronic gauge with a GRM of 0.1mb) Minimum Purge Flow Rate (MPFR)

Purge Point Dimensions and Locations The Maximum Purge Time (Max PT) allowed for purging to each purge point – using the formula Max PT(secs) = 1.5 x V x 3600/MPFR. The purge points have been numbered in the order of the purge i.e. starting with the most remote point on the network and progressing back towards the purge gas injection point. In order to keep the complexity of this procedure to a reasonable level, the number of purge points within each MZ has been limited to the ends of the spine main and the ends of the larger branch mains, i.e. those branch mains with volumes of 1 cubic meter or more. The purge points for branch mains and services with volumes of less than 1m3 are not specifically referred to. In addition, since the system is to be re-commissioned, it is not proposed to purge these low volume sections to nitrogen in the event of a complete loss of pressure; however they will be purged to gas through hoses attached to the ECV’s once supplies are restored. To ensure no ECV’s are missed, lists have been prepared for each MZ/sector. These will be issued to the University’s Corgi registered plumbers who will record the fact that the required action has been taken at each stage in the process. 3. Site Precautions The following precautions will be taken throughout the procedure: Appropriate “No Smoking” signage shall be displayed around any vent and elsewhere if necessary. All valves will be labelled clearly “Do not Operate - Purge in Progress”. Mobile phones will be used to co-ordinate remote activities. Care will be taken to ensure they are not taken into or used in gaseous atmospheres. Any electrical continuity bonds will be maintained throughout the purging operation. Two fire extinguishers will be situated close to any open purge point. When positioning purge points and hoses, precautions shall be taken to reduce the hazards associated with venting by avoiding venting close to air intakes or sources of ignition. Venting will not take place close to electrical equipment and no electrical switches will be operated during venting. Hoses shall be long enough to vent the gas to atmosphere away from buildings and ignition sources. The end of the purge hose/stack shall be in the open air, at least 5m down wind of any potential ignition source and at least 2.5m above ground level, and precautions will be taken to prevent vented gas drifting into buildings. 4. Plant and Equipment The following plant and equipment is required: Bypass rig (80mm/3 inch diameter) with integral valve Note: A 3 inch diameter rider 3m long with 4 elbows and 2 inline gate valves (full bore) is equivalent to 10.5 m of straight pipework and will pass 216 cu. m/hr with a pressure drop of 2.0mb.

Flow rate meter The purge point diameters have been sized to ensure the required purge velocities will be achieved providing the inlet pressure to the purge points is 19mb or more. For example a 5m purge hose/stack 100mm diameter will pass the minimum required flow rate (216 m3/hr) for a 12” diameter main with a pressure drop of less than 1.0mb. However if in doubt a rate of flow meter capable of measuring up to 300m3/hr may be fitted between the purge point and the hose. One bank of nitrogen cylinders (11 bottles) with a high capacity pressure regulator size to deliver a flow rate of 216 cu. m/hr Note: Obtain confirmation from the cylinder supplier that the cylinder contains nitrogen. The required number of 5m long non-metallic (and not PE or any material that may generate static) purge hoses with sampling points. Two natural gas detectors Note: Any electronic detectors (or other equipment such as test gauges) used shall: * be certified for use in hazardous areas; * be operated in accordance with the manufacturers instructions; * have their batteries tested prior to use; * be zeroed at the commencement of each test and have their zero’s checked at the finish of each test * be tested, overhauled and calibrated in accordance with the manufacturer’s instructions. Sufficient water gauges calibrated in mb Sufficient fire extinguishers i.e. two at each purge point. 5. Supervision and Manpower The University Estates Operations Manager will ensure there are sufficient competent staff available e.g. a mainlayer craftsman (GD4 or equivalent), supervisor and sufficient support operatives. The supervisor must be able to demonstrate competency to supervise the work and have at least 3 years relevant experience. Ideally he/she would have achieved NVQ Level 3 in Gas Network Operations or an equivalent qualification. 6. Nitrogen Purge The following procedure is to be followed for each MZ (and for each sector in the case of MZ 3) if the pressure has fallen to atmospheric pressure. Note: A data sheet has been prepared for each MZ/sector and is filed with the MZ plans at the end of this appendix. Walk the site and suspend any work on or adjacent to the network that could result in pipe damage, or pipework being left open-ended, and be alert for third party work in the vicinity.

Inform the Cadent Gas emergency service on 0800 111 999 and the University site security office of the start of the procedure and advise them to be alert for reports of gas leakage. Taking each MZ (or sector) in turn: 6.1 Close all emergency control valves (ECV’s) and label “Do Not Open - Purge in Progress”. 6.2 Check that the primary meter outlets are isolated and that nitrogen cannot pass into the upstream

system.

Note: A suitable method of isolating the downstream pipework from the primary meter installation has been devised (i.e. the network isolation method). This is to ensure air or nitrogen does not enter the upstream system and will be achieved by one of the following methods; disconnecting and capping the primary meter outlet main, squeezing off the P.E. mains, or closing a valve. Where a valve is used it will have integral double block and bleed features; the bleed facility will be piped to a surface box and will terminate in a full bore valve.

6.3 Install the nitrogen injection point immediately downstream of the MZ primary meter isolation

method.

Note: For MZ 3 ensure all sector valves are closed. The sequence of purge will be to progress in numerical order from sector 1 to sector 4. The nitrogen injection points will be immediately downstream of the sector valves.

6.4 Ensure the MZ normal operating pressure (NOP) will not be exceeded by installing and monitoring

a water gauge to a pressure point immediately adjacent to, and downstream of, the nitrogen injection point.

6.5 Ensure the nitrogen regulator is capable of delivering the minimum purge flow rate (MPFR) for the

MZ, connect the nitrogen cylinder/s and leave closed. Note: A high capacity regulator will pass 66m3/hr at 10 barg; this is well in excess of the MPFR for the MZ’s/sectors.

6.6 Install purge hoses/stacks and water gauges at all purge points as marked on the MZ plans. Leave

all purge points closed. 6.7 Fully open pp1 and then open the nitrogen inlet valve, commence the purge and increase the flow

rate until the pressure in the main at the injection point reaches 19mb but ensure the NOP is not exceeded. If 19mb cannot be achieved with the nitrogen regulator fully open the MPFR will be achieved providing the pressure in the cylinders is 5 barg or more.

Simultaneously start the timer and continue the purge until a reading of 1.8% gas in air (or less) is achieved. This should occur before the maximum permitted purge time has elapsed.

Note: If the 1.8% gas in air is not achieved within the maximum permitted purge time it is probably because the required flow rate is not being achieved. In this case it will be necessary to identify the reason for the problem, rectify it and repeat the purge process.

6.8 Upon completion of the purge, close the nitrogen inlet and then purge point 1.

6.9 Proceed to pp2, open the purge point and then the nitrogen inlet valve and commence the purge. Increase the flow rate whilst monitoring the pressure to ensure the NOP is not exceeded.

Simultaneously start the timer and continue the purge until a reading of 1.8% gas in air (or less). This should occur before the maximum permitted branch purge time has elapsed.

6.10 Upon completion of the purge close the nitrogen inlet and then purge point 2. 6.11 Repeat step 6.8 and 6.9 for all remaining pp’s in the MZ.

Important Note: To avoid making this process overly complicated (and thereby increasing the risk of human error) and because the pipework is to be re-commissioned as soon as possible, it is not proposed to nitrogen purge each service pipe nor any small diameter branch mains with volumes of less than 1m3. (See MZ data sheets attached).

6.12 Complete a purging certificate

Note: these can be purchased from IGEM. 6.13 Unless the tightness test (section 7 below) is to be carried out immediately, disconnect the

nitrogen cylinder/s, plug and test the injection point. 7. Tightness Testing (using Nitrogen) The following tightness test must be carried out immediately prior to purging to gas and re-commissioning each MZ/sector. 7.1 Walk the route of the network and carry out a physical check to ensure there are no obvious signs

of interference damage and that all ECV’s remain closed. 7.2 Re-connect the nitrogen cylinder/s and install pp1 and leave both closed. 7.3 Open the nitrogen injection valve and allow the pressure in the network to rise to the NOP of the

network. Take care to ensure the NOP is not exceeded. 7.4 Close the nitrogen injection valve; allow 15 minutes for stabilisation. 7.5 During this time check that the MZ isolation valves (or squeeze offs) are not allowing gas “let-by”

by testing the open bleed facility with leak detection fluid (wash off after use). 7.6 Monitor pressure in the network for the TTD of the network. If the pressure does not drop by

greater than the GRM, i.e. 0.5mb for a water gauge, during the TTD monitoring period the network has passed.

7.7 If the pressure falls by more than 0.5mb during the TTD the test has failed. If however the pressure

has dropped between 0.5 and 2.0mb the actual leak rate must be calculated (see section 5.7.4.2 IGE/UP/1 Edition 2) and if this is less than or equal to 0.03m3/hr the test has passed. If the leak rate is higher than 0.03m3/hr the leak/s must be traced and repaired and the test repeated.

7.8 If the retest still indicates leakage, it will be from the below ground system and could prove

impractical to locate using nitrogen as a test medium. In these circumstances a risk assessment will be carried out before proceeding to section 8 below. The risk assessment will take into consideration the volume of leakage calculated. If the leak rate is significantly in excess of

0.03m3/hr consideration should be given to calling in specialists to perform an SF6 leak location service.

7.9 The results of this test must be documented and retained.

Note: For this purpose a copy of this procedure can be used. Each step within the process must be ticked and initialed by the gas person in charge as it is completed. At the end of the procedure the document must be signed and dated again by the University person in charge. In addition a test certificate (see pg 132 of IGE/TD/3 Edition 4) must be completed.

8. Natural Gas Purge The following procedure is to be followed immediately after the tightness test. 8.1 Inform the Gas Supplier of the procedure and request attendance of the Meter Asset Operator

(i.e. Cadent Gas) maintenance staff responsible for operation of the primary meter installations. 8.2 Inform the Cadent Gas emergency service on 0800 111 999 and the University site security office

of the start of the procedure and advise them to be alert for reports of gas leakage. 8.3 Check with Cadent Gas that their system and meter are capable of supplying the Minimum Purge

Flow Rate (MPFR)* without reducing upstream pressures to unacceptable levels. *Note: The MPFR is the same as the MPFR for the nitrogen purge above. See MZ data sheets.

8.4 Walk the site and suspend any work on or adjacent to the network that could result in pipe damage, or pipework being left open-ended, and be alert for third party work in the vicinity; carry out a physical check to ensure there are no obvious signs of interference damage.

8.5 Ask the Meter Asset Operator’s staff to purge the upstream side of the primary meter outlet valve

and set the meter rig to feed at the NOP of the MZ. 8.6 Erect a 90mm/3” diameter bypass and pressure points across the primary meter outlet isolation

method and leave the bypass end closed. 8.7 Fully open pp1. 8.8 Install and monitor a water gauge either side of the primary meter outlet isolation method. 8.9 Commence the purge by slowly (but fully) opening the bypass valve, monitor the pressures either

side and start the timer.

Note: The minimum pressure on the upstream side of the meter to be agreed with Cadent staff and the maximum pressure in the MZ/sector not to exceed the NOP.

8.10 Check with NG staff that the meter is functioning correctly and that inlet and outlet pressures are

correct.

Continue the purge until a reading of 90% gas in air (or more) is achieved at pp1.

This should occur before the maximum purge time* for the network has elapsed.

*Note: The maximum purge time is the same as the MPT for the nitrogen purge above.

Note: If the 90% gas in air is not achieved within the maximum permitted purge time it is probably because the required flow rate is not being achieved. In this case it will be necessary to identify the reason for the problem, rectify it and repeat the purge process.

8.11 Close the pp1, taking care to ensure the normal operating pressure of the network is not

exceeded. 8.12 Proceed to pp2, open the purge point/s and commence the purge of the branch. Simultaneously

start the timer and continue the purge until a reading of 90% gas in air (or more) is achieved. This should occur before the maximum permitted purge time for the branch has elapsed.

8.13 Once the purge is complete close pp2. 8.14 Repeat steps 8.12 and 8.13 for all remaining pp’s in the MZ/sector. 8.15 Once the purge is complete check that pressures have equalised across the primary meter outlet

isolation method and remove the isolation method whilst monitoring the pressures either side. Ensure the NOP is not exceeded.

8.16 Immediately after completing the gas purge, carry out an above ground walking leakage survey

using suitable hand-held gas detection equipment.

Note: This is particularly important if the leak rate calculated in 7.8 above has exceeded 0.03m3/hr. In these circumstances bar holes must be made in sealed surfaces and all service entries, drains and ducts into the buildings must be checked with a gas detector on the ppm scale.

8.17 Ensure all open ends are capped (or plugged) with an appropriate fitting and test any disturbed

joints with leak detection fluid. Wash off leak detection fluid. 8.18 The results of this purge must be documented and retained.

Note: For this purpose a copy of this procedure can be used. Each step within the process must be ticked and initialed by the person in charge as it is completed. At the end of the procedure the document must be signed and dated.

Note with respect to the Hydeploy project The purging and recommission of MZ3 when hydrogen enriched methane is introduced into the network has been addressed by Cadent gas document reference GD/PR/EM/72-H – Supplementary guidance for attending to gas emergencies and meter work at Keele University during the Hydeploy project. Specific guidance for purging and commissioning is detailed as follows:-

1. Mains Commissioning

a. Where it becomes necessary to purge and commission any new sections of main while the Hydeploy trial is in place, the first choice will be to complete the purging operation using bottled natural gas.

b. Whether the purging operation is a slug purge (using nitrogen) or a direct purge, the final part of this operation, is planned to be completed using bottled natural gas for the gas section of the purge.

c. The existing process and calculations necessary for purge duration, and the use of existing gas detection equipment will be the same as at present.

d. The site specific details, appropriate to each location, will be detailed in a documented routine operation permit, as currently exists. In the event of a non-routine operation becoming necessary, consideration would be given to the shutting down of the blender, and reverting back to natural gas, and using existing approved methods of commissioning.

e. For mains commissioning on bottled natural gas then a traditional calibrated Bascom Turner OR Gasco Seeker instrument shall be used to determine gas readings

2. Mains Decommissioning

a. If and when it becomes necessary to decommission a gas main, existing approved documented methods will continue to be used,

b. The existing process and calculations necessary for purge duration, remain the same as presently exist.

c. Where it is determined that a blended gas is present in a main to be decommissioned then detection equipment specified for the trial and supplied by Keele University shall be used. This detection equipment will be the GMI GS700 which will be calibrated to retain the 40% LEL accepted level to indicate a decommissioning purge has been completed.

3. Services Commissioning.

a. Purging operations for gas services <= 2” dia can continue to completed as existing procedures (purge for at least 1 M/sec, with a minimum of 5 sec. directly following a successful pressure test at 100 mbar)

4. Services Decommissioning.

1. Where it is determined that a blended gas is present in a gas service to be decommissioned then detection equipment specified for the trial and supplied by Keele University shall be used. This detection equipment will be the GMI GS700 which will be calibrated to retain the 40% LEL accepted level to indicate a decommissioning purge has been completed.When purging Industrial and Commercial type installations the following additional guidance is provided:-

a. Purging has four methods: Air to Gas; Gas to Air; Air to Nitrogen to Gas and Gas to Nitrogen to Air. There is a level of detection that determines when each step in the method is complete.

b. When purging from Air to Gas IGEM/UP/1 requires a minimum gas detection reading of 90% GIA to be taken at the vent stack within the purge time. As it will not be possible to achieve this figure and to ensure a safe purge has been completed it is recommended that bottled NG is used. For commissioning on bottled natural gas then a traditional calibrated Bascom Turner instrument shall be used to determine gas readings

c. When purging from gas to air IGEM/UP/1 requires a gas detection reading of 40% LEL to be taken at the end of the purge. Detection equipment specified for the trial and supplied by Keele University shall be used. This detection equipment will be the GMI GS700 which will be calibrated to retain the 40% LEL accepted level to indicate a decommissioning purge has been completed.

2. Any individual or organization undertaking purging and commissioning operations shall have received the necessary training in these procedures and be accredited to undertake such work on the hydrogen enriched system (MZ3

Guidance should a gas escape be present when carrying out purging and commissioning operations:- Guidance is provided in KU/Gas/17 The University of Keele Procedure for dealing with gas escapes on the Hydeploy system

9. Re-commissioning procedure IMPORTANT NOTE: In order to keep the complexity of this procedure to a reasonable level, the number of purge points within each MZ/sector has been limited to the ends of the spine main and the ends of the larger branch mains i.e. those branch mains with volumes of 1m3 or more. Therefore the branch mains and services with volumes of less than 1m3 may still contain air or nitrogen and consequently they must be purged until a reading of 90% G.I.A. through hoses attached to the outlet of the ECV’s is attained. Purge point and hose sizes required are set out below as an example:

Service/Branch Pipe diameter Purge point bore Purge hose bore

Upto 40mm mm mm

Upto 100mm mm mm

Upto 125mm mm mm

9.1 Before re-commissioning supplies to individual properties, attach a purge hose to the outlet of the

ECV and purge the service pipe/ branch main for a minimum of 1 second/metre length of the service/main and for longer if necessary until two consecutive readings of 90%GIA are obtained. For MZ3 bottled natural gas shall be utilised and a traditional calibrated Bascom Turner instrument shall be used to determine gas readings

9.2 Gas supplies to the secondary meters and appliances can now be restored to gas users by the

University’s Gas Safe registered personnel following the University’s procedures for pressure testing, purging and appliance re-commissioning. As each property is re-commissioned the “Do Not Open - Purge in Progress” labels must be removed from the ECV’s.

9.3 Carry out a mail shot advising consumers that the procedure is complete and thanking them for

their co-operation and allow any suspended works to recommence. 10. Record keeping A written record of each step of the procedure must be made and kept, together with any notes of deviations from this procedure taken by the gas competent person. For this purpose a copy of this procedure can be used. Each step within the process must be ticked and initialled by the gas competent person as it is completed. At the end of the procedure the document must be signed and dated again by the University gas competent person. These records should be retained with the purge, tightness test and leakage survey results, for reference purposes. 11. Data Sheets

DATA SHEET MZ 1 – Meter No G1 – Clock House Main Meter Key: TTP = Tightness Test Pressure; TTD = Tightness Test Duration; MPFR = Minimum Purge Flow Rate; GRM = Gauge Readable Movement (TTD calculated using a water gauge with GRM = 0.5mb); PP = purge pt. Max PT = Maximum Purge Time. Note 1: The TTD’s have been calculated using the formula given in Table 9 –IGE/UP/1 Edition 2, i.e. TTD = 0.047GRM x IV x F1, where GRM = 0.5mb, IV = Internal Volume and F1 = 67 (from table 10). Note 2: The Max PT’s have been calculated by making an estimate of the volume of each branch (scaled from the drawing) and assuming the minimum required purge flow rate (taken from table 12, IGE/UP/1 Edition 2) for the maximum diameter pipe in the branch will be achieved by fully opening the purge point. The formula used is taken from paragraph 6.9.4, IGE/UP/1 Edition 2 i.e. Max PT (sec) = PV(m3) x 3600 Q where PV = 1.5 x IV and Q = MPFR. Note 3: In order to keep the complexity of this procedure to a reasonable level, the number of purge points within each MZ has been limited to the ends of the spine main and the ends of the larger branch mains i.e. those branch mains with volumes of 1m3 or more. The purge points for branch mains and services with volumes of less than 1m3 are not specifically referred to. In addition it is not propose to purge these low volume sections to nitrogen in the event of a complete loss of pressure; however they will be purged to gas through hoses attached to the ECV’s once supplies are restored. 1) LP System Horwood estate Pipe Data*: Diameter/Material Length (m) Volume (m3) 180mm/MDPE 200 3.40 125mm/MDPE 60 0.48 90mm/MDPE 90 0.36 63mm/MDPE 400 0.84 Total Volume = 5.08 TTP = 28mb; TTD = 8mins; MPFR = 38cu.m/hr; Location of PP at Horwood Block Z9, PPD’s; Nominal bore of PP = 40mm, hose/stack bore = 50mm; Max PT = 9mins 48secs. Keel Hall, Horwood Staff Housing and Springpool (Added February 2018) Pipe Data*: Diameter/Material Length (m) Volume (m3) 8inch/steel 5 0.13 6inch/ steel 210 3.07 4inch/ steel 88 0.57 2inch /steel 17 0.03 250mm/MDPE 150 5.73

125mm/MDPE 38 0.36 63mm/MDPE 96 0.23 Total volume = 10.13 TTP = 28mb; TTD = 16mins; MPFR = 38cu.m/hr; Location of PP at Springpool extremities, PPD’s; Nominal bore of PP = 40mm, hose/stack bore = 50mm; Max PT = 24mins 2) MP System Pipe Data*: Diameter/Material Length (m) Volume (m3) To Horwood 250mm/MDPE 680 21.76 125mm MDPE To Lindsay 180mm/MDPE 300 6 TTP = 140mb, TTD** = 7 mins, MPFR = 141m3/hr. PPD’s:

Location Purge point bore Hose/stack bore Max PT

pp1 Horwood G7 (a) 80mm 100mm 7mins 20secs

Horwood G7 (b)

pp2 Lindsay Main G20 40mm 50mm 12mins 54secs

* All pipe data has been taken from plan S-G-MZ1 and is approximate. **Using an electronic gauge with a GRM = 0.1mb 3) New governor outlet MZ1 also comprise the following Low Pressure pipes comprising the outlet pipework from a new University governor installation:

63mm MP supply to MP/LP module 5.0 metres

63mm LP supply to Greenhouse boiler 9.0 metres

90mm LP supply to external of Clock House kitchen 75.0 metres

63mm LP supply to Clock House boilers 12.0 metres

32mm LP supply to Clock House Kitchen 10.0 metres

32mm LP supply to Firshill 68.0 metres TTP = 28mb; TTD = 39Secs; Max PT = 4mins 44secs for complete system. Each leg of the system will be purged from individual purge hoses attached to pipe extremities at each plant room. Recommended purge point bores (PPB) and hose stack bores (HSB) are as follows:-

63mm Greenhouse boiler – PPB=25mm, HSB=40mm

90mm Clock House kitchen - PPB=25mm, HSB=40mm

63mm Clock House boilers - PPB=25mm, HSB=40mm

32mm Clock House Kitchen - PPB=20mm, HSB=20mm

32mm Firshill - PPB=20mm, HSB=20mm DATA SHEET MZ 3 - Meter No. G3 – Main Campus Key: TTP = Tightness Test Pressure; TTD = Tightness Test Duration; MPFR = Minimum Purge Flow Rate; GRM = Gauge Readable Movement (TTD calculated using a water gauge with GRM = 0.5mb); PP = purge pt.; Max PT = Max purge Time. Note 1: The TTD’s have been calculated using the formula given in Table 9 –IGE/UP/1 Edition 2, i.e. TTD = 0.047GRM x IV x F1, where GRM = 0.5mb, IV = Internal Volume and F1 = 67 (from table 10). Note 2: The Max PT’s have been calculated by making an estimate of the volume of each branch (scaled from the drawing) and assuming the minimum required purge flow rate (taken from table 12, IGE/UP/1 Edition 2) for the maximum diameter pipe in the branch will be achieved by fully opening the purge point. The formula used is taken from paragraph 6.9.4, IGE/UP/1 Edition 2 i.e. Max PT (sec) = PV(m3) x 3600 Q where PV = 1.5 x IV and Q = MPFR.

Note 3: In order to keep the complexity of this procedure to a reasonable level, the number of purge points within each MZ has been limited to the ends of the spine main and the ends of the larger branch mains i.e. those branch mains with volumes of 1m3 or more. The purge points for branch mains and services with volumes of less than 1m3 are not specifically referred to. In addition it is not propose to purge these low volume sections to nitrogen in the event of a complete loss of pressure; however they will be purged to gas through hoses attached to the ECV’s once supplies are restored. DATA SHEET MZ 3 - Meter No. G3 – Main Campus Sector 1 Pipe Data*: Diameter/Material Length (m) Volume (m3) 250mm/MDPE 220 7.04 180mm/MDPE 90 1.53 125mm/MDPE 770 6.16 90mm/MDPE 590 2.36 63mm/MDPE 520 1.09 4”/ Steel 160 1.44 Total Volume = 19.62 TTP = 28mb, TTD = 32mins, MPFR = 141 m3/hr. PP data:

Location Purge point bore Hose/stack bore Max PT

pp1 Inlet of Sector valve V1 80mm 100mm 4mins 30secs

pp2 Drive Lodge 40mm 50mm 3mins 48secs

pp2 Leisure Centre 40mm 50mm 31secs

pp3 217 Church Plantation 40mm 50mm 9mins 36secs

pp4 41 the Covert 40mm 50mm 4mins 48secs

DATA SHEET MZ 3 - Meter No. G3 – Main Campus Sector 2 Pipe Data*: Diameter/Material Length (m) Volume (m3) 180mm/MDPE 540 3.84 63mm/MDPE 480 1.01 6”/ Steel 40 0.80 Total Volume = 5.65 TTP = 28mb, TTD = 9mins, MPFR = 30 m3/hr. PP data:

Location Purge point bore Hose/stack bore Max PT

pp1 Taylor House 40mm 50mm 5mins 55secs

pp2 Harrowby 40mm 50mm 3mins 50secs

pp3 Huxley Building 40mm 50mm 4mins 48secs

DATA SHEET MZ 3 - Meter No. G3 – Main Campus Sector 3

Pipe Data*: Diameter/Material Length (m) Volume (m3) 250mm/MDPE 30 0.96 180mm/MDPE 250 4.25 125mm/MDPE 110 0.88 90mm/MDPE 80 0.36 63mm/MDPE 520 1.09 Total Volume = 7.54 TTP = 28mb, TTD = 14mins, MPFR = 141 m3/hr. PP data:

Location Purge point bore Hose/stack bore Max PT

pp1 Inlet of Sector Valve V3 80mm 100mm 2mins 46secs

pp2 William Smith Building 40mm 50mm 2mins 52secs

pp2 Chancellor building 40mm 50mm 48 secs

DATA SHEET MZ 3 - Meter No. G3 – Main Campus Sector 4 Now included in Meter Zone 1 DATA SHEET MZ 3 – For gas mains to be adopted by the University for the Hydeploy project The pipework off take from the electroliser point together with G3 Governor and its associated

supply pipework is being adopted by the University for the duration of the project.

The additional sections of gas main are listed as follows:-

255m of new MP 180 MDPE connecting the electroliser to MZ3 network – Volume =5.05 m3

o TTP = 28mb, TTD = 14mins, MPFR = 141 m3/hr. Max Purge Time 10.23 mins

175 meters of existing MP 6" steel main and 89 meters of existing MP 180mm MDPE supplying the G3 governor – Volume = 4.32 m3

o TTP = 28mb, TTD = 7.95mins, MPFR = 141 m3/hr, . Max Purge Time 11.96 mins

The purge point location for G3 Governor will selected from a suitable purge point within the

enclosure

The purge point locations for the electroliser and associated pipework will be selected depending on

local conditions at the time the operation is carried out.

Note:-

Any subsequent testing and purging operation for these assets will be subject to a bespoke None

Routine Operations procedure (NRO). The purge and test data provided above is for illustrative

purposes only

DATA SHEET MZ 5 – Meter No. G005 – Hawthorns Legally transferred to a third-party entity DATA SHEET MZ 6 – Meter No. G006 Hawthorns LFA Legally transferred to a third-party entity DATA SHEET MZ 7 – Meter No. G 340 – Barnes W & X Key: TTP = Tightness Test Pressure; TTD = Tightness Test Duration; MPFR = Minimum Purge Flow Rate; PPD = Purge Point Dimensions; GRM = Gauge Readable Movement (TTD calculated using a water gauge with GRM = 0.5mb); PP = purge pt. Pipe Data*: Diameter/Material Length (m) Volume (m3) 63mm 100 0.20

TTP = 28mb, TTD = 5** mins, MPFR = 34.5 cm/hr, PPD’s; Location of PP at Barnes block W; nominal bore of PP = 25mm; hose/stack bore = 40mm; Max PT = 1 sec/metre = 100secs. **IMPORTANT NOTE: Because the volume is less that 1.0 m3 there is no need to carry out a nitrogen purge. Before re-commissioning, survey the route of the pipe to check there are no signs of damage. Carry out a direct purge from air to gas and carry out a drop test at working pressure for 5 minutes. If there is no loss of pressure during this time the pipe can be re-commissioned. *All pipe data has been taken from drawing MZ 7 and is approximate.

DATA SHEET MZ 8 - Meter No. G360 – Barnes Key: TTP = Tightness Test Pressure; TTD = Tightness Test Duration; MPFR = Minimum Purge Flow Rate; GRM = Gauge Readable Movement (TTD calculated using a water gauge with GRM = 0.5mb); PP = purge pt.; Max PT = Max purge Time. Note 1: The TTD’s have been calculated using the formula given in Table 9 –IGE/UP/1 Edition 2, i.e. TTD = 0.047GRM x IV x F1, where GRM = 0.5mb, IV = Internal Volume and F1 = 67 (from table 10). Note 2: The Max PT’s have been calculated by making an estimate of the volume of each branch (scaled from the drawing) and assuming the minimum required purge flow rate (taken from table 12, IGE/UP/1 Edition 2) for the maximum diameter pipe in the branch will be achieved by fully opening the purge point. The formula used is taken from paragraph 6.9.4, IGE/UP/1 Edition 2 i.e. Max PT (sec) = PV(m3) x 3600 Q where PV = 1.5 x IV and Q = MPFR. Note 3: In order to keep the complexity of this procedure to a reasonable level, the number of purge points within each MZ has been limited to the ends of the spine main and the ends of the larger branch mains i.e. those branch mains with volumes of 1 m3 or more. The purge points for branch mains and services with volumes of less than 1 m3 are not specifically referred to. In addition it is not propose to purge these low volume sections to nitrogen in the event of a complete loss of pressure; however they will be purged to gas through hoses attached to the ECV’s once supplies are restored. Pipe Data*: Diameter/Material Length (m) Volume (m3) 180mm/MDPE 595 11.79 100mm/ PE? 50 0.24 90mm/MDPE 100 0.40 63mm/MDPE 100 0.21 Total Volume = 12.64 TTP = 28mb, TTD = 20 mins, MPFR = 79&216 m3/hr, PPD’s; PP data:

Location Purge point bore Hose/stack bore Max PT

pp1 Barnes Hall Block O 80mm 150mm 4mins 7secs

pp2 Barnes Launderette 40mm 50mm 2mins 17secs

pp3 Barnes Block Y 50 100 7 mins

*All pipe data has been taken from plan S-G-MZ8 and is approximate.