Operating Instructions for C3F8 Supply Lines ATLAS Project
Contents
1. V9 V11 V12 closed V10 open C3F8 bottle on scales connected to schraeder valve with bottle valve closed Le following Operation 2 Step ResulComment Record weight of C3F8 bottle So you know when to stop 2 Check put safely all valves are Safety of flow meters vacuum pump etc inte appropria iia NT 3 Check Pvac is low below Do not waste C3F8 by mixing it with moist air etc simrenocs eee Close V10 Isolate C3F8 Plant from supply pipes Open valve on C3F8 bottle C3F8 Plant is full of C3F8 gas at about 6 9 bar g Turn on compressor separate in C3F8 evaporates in bottle and condenses in HE1 structions cool HE1 to min imum temperature See C3F8 plant instructions 7 Watch weight of C3F8 bottle Desired quantity of C3F8 is in the C3F8 Plant When desired amount 3 kg 2 1 transferred close valve on C3F8 bottle Remove C3F8 tube from Bottle can be removed to storage schraeder valve replace seal on valve Turn compressor off C3F8 pressure rises slowly to about 6 9 bar g T E A oo T E S E E E a e e E a a cae EE a a a RT Table 1 Bottle weight history ATLAS Project Document No Page 8 of 12 4 Operation 4 Preparing for Disc Cooldown In the following V4 V6 and V13 apply to the Disc Box V5 V7 and V14 apply to the Cylinder Box 4 1 Operation 4 1 Flushing with Nitrogen Initial state Compressor off liquid pump off vacuum pump off C3F8 Plant full of warm C3F8 at about 62. vacuum off circuit full of dry nitrogen at atmo spheric pressure V3 V4 V5 V6 V7 V8 V9 V11 V12 closed V1 V2 V10 open i e following Operation 1 DO NOT CARRY OUT THIS OPERATION WITH C3F8 IN THE SYSTEM Step Resul Comments 1 Check all valves are in the ap Safety of flow meters vacuum pump etc propriate initial state 2 Check Pvac is about 1 bar abso Avoid putting excess pressure on vacuum pump lute if above open V3 briefly to bring down to 1 bar if below open V8 briefly to top up with dry nitrogen Close V1 and V2 Prevent reverse flow through flow meters 4 Open V12 and turn on the vac Inlet side of vacuum pump pressure drops uum pump Open V9 Circuit evacuation starts Wait till Pvac and other pressure Circuit is evacuated with remnant dry nitrogen meters show circuit is evacuated about 1 mbar 7 Close V12 and V9 then turn vac uum pump off Final state C3F8 Plant and Supply Lines are at vacuum from V6 V7 to V1 V2 with 1 mbar dry nitrogen Circuit lines from V1 V2 to V4 V5 have nitrogen at 1 bar Circuit lines from V4 V5 to V6 V8 unchanged The circuit can again be checked for leaks by watching how fast the pressure rises Do not proceed until the circuit is leak tight ATLAS Project Document No Page 7 of 12 3 Operation 3 Fill Plant With C3F8 Initial state Compressor off liquid pump off vacuum off circuit full of dry nitrogen at vacuum of 1 mbar V1 V2 V3 V4 V5 V6 V7 V8
3. V10 fully Open SV By pass liquid pump 5 Open V1 or V2 depending on Cooling circuit is open ready to start cooling which flow meter is wanted Final state C3F8 Plant Supply Lines Disc circuits are full of warm C3F8 at about 6 bar Circuit is ready for cooling with flow via required flow meter ATLAS Project Document No Page 10 of 12 5 Operation 5 Evacuating C3F8 to Plant and Preparing For Disc Removal Initial state Cooling running Compressor on liquid pump on vacuum pump off disc in place full of C3F8 Either V1 or V2 open the other closed either V4 and V6 or V5 and V7 open the other two closed V10 open V3 V8 V9 V11 V12 closed Make sure all cooling circuit components including the heat exchangers in the Disc or Cylin der Box are open for coolant flow Do not leave unattended while evacuating If cooling machine trips off the pressure in the vacuum pump rises very quickly unless V10 and V11 are quickly closed off Step Resul Comments Turn off all power to the disc Cooling no longer needed 2 Close V2 or V1 so both are C3F8 supply to disc stopped closed Open SV Keep C3F8 circulating via by pass cools C3F8 bet ter 4 Turn R404 set point temperature C3F8 in HE1 cools down further pressure in circuits to the minimum possible drops C3F8 in circuits evaporates and condenses in HE1 5 Wait till disc has warmed up Discs warms up when all C3F8 has evaporated now there is no more liqui
4. bar supply lines full of air at pressure of 1 bar disc cooling circuits connected up and sealed unused cooling circuits in test boxes sealed off V1 V2 V3 V4 V5 V6 V7 V8 V9 V10 V11 V12 closed ResulComments Check all Supply Line valves are Avoid loss of C3F8 to atmosphere closed and supply lines on disc side of V1 V2 V10 have no C3F8 in or maximum 1 mbar C3F8 as after Operation 5 Open V4 and V6 or V5 and Circuit is open for flushing V7 N regulator to 0 Open V8 Allows leak check see how quickly the pressure slowly raise N regulator to high drops Probably want to close inlet valves on disc pressure e g 19 bar g close and V13 or V14 V8 Open V3 Vent the nitrogen to atmosphere 5 Set nitrogen regulator to about Flushing starts Note the disc circuits are flushed Wait for sufficient flushing Supply Lines and disc cooling circuits are full of dry V3 Final state C3F8 Plant is full of warm C3F8 Supply Lines and disc circuits are full of dry nitrogen at about atmospheric pressure Do not proceed until the circuit is leak tight ATLAS Project Document No Page 9 of 12 4 2 Operation 4 2 Evacuating to Atmosphere Initial state Compressor off liquid pump off vacuum pump off C3F8 Plant full of warm C3F8 at about 6 bar Supply Lines and disc circuits full of dry nitrogen at about atmospheric pressure unused cooling circuits in test boxes sealed off V1 V2 V3 V8 V9 V10 V11 V12 clos
5. 6 2 Recuperation of residual C3F8 gas aoaaa e 12 ATLAS Project Document No Page 3 of 12 Introduction This document gives instructions for operating the C3F8 cooling system for the ATLAS SCT Discs The cooling system can broadly be split into four components the C3F8 Cooling Plant C3F8 Plant the supply and return lines with their associated valves vacuum system purge lines etc Supply Lines the disc test box Disc Box and the cylinder test box Cylinder Box Figure 1 shows how the supply lines interconnect the cooling plant with the test boxes and labels the valves with the names used in this document R Version 4 26 1 05 V V12 Vent to atmosphere X ea VQ pump S m N2 Supply passsssmsnd VQ v7 Ove m Ao V13 QR Disctest V6 box C3F8 plant ridge V4 FM2 7 D sv 4 FMi NTS ao soe Cs bt Ae eae S EENEN Ove o PONE nana By pass valve Cylinder i Filter Vent to test box atmosphere FM1 precision low rate flow meter Used to set restrictors and check individual circuit flows FM2 High rate flow meter used for monitoring most of the time 0 bess i Figure 1 Supply lines between C3F8 Plant and Test Boxes with valve labels Certain operations can cause damage to equipment loss of C3F
6. 8 which is expensive and bad for global warming or risk of personal injury Hence it is important to follow the instructions closely Use gloves to avoid contact with cold surfaces Use goggles if there is a risk of C3F8 escape especially relevant if adjusting the restrictors Once the Cooling Plant and Supply Lines are ready for use they have to be filled with C3F8 ATLAS Project Document No Page 4 of 12 This requires a sequence of operations detailed below Operation 1 Flush lines with nitrogen Operation 2 Evacuate lines to atmosphere Operation 3 Fill plant with C3F8 Thereafter each time a disc is put in a circuit Operation 4 Preparing for Disc Cooldown has to be carried out Each time the disc tests are finished Operation 5 Preparing for Disc Removal has to be carried out before removing a disc or opening its cooling circuits In the event of problems with the C3F8 Plant or the Supply Lines and at the end of all tests the C3F8 has to be removed from the system Operation 6 Final Removal of C3F8 achieves this For all operations start the DCS and make sure at least one inlet and one outlet electro valves are open to the differential pressure sensor this will avoid putting too large a pressure across it Valves V13 and V14 these were added later and are not mentioned in the instructions They should generally be left open They are for the specific purpose of leak checking the on disc cooling circuits by reducing the
7. Operating Instructions for C3F8 Supply Lines Ul ATLAS Project Doc No Institute Doc No Created 28 4 2004 Page 1 of 12 Modified 26 1105 Operating Instructions for C3F8 Supply Lines This manual gives instructions for purging evacuating and filling the C3F8 cooling system and connecting disconnecting discs to the cooling system Prepared by Checked by Approved by N P Hessey Nobody Nobody Distribution List A P Colijn H Boer Rookhuizen P Werneke R Buis ATLAS Project Document No Page 2 of 12 History of Changes Made by Description of changes 28 4 04 NP Hessey Original document B 28 7 04 NP Hessey Safety warnings dP protection new fig 1 etc C 26 1 05 Many NP Hessey V13 and 14 many small improvements learnt from experience List of Figures 1 Supply lines between C3F8 Plant and Test Boxes with valve labels 3 Contents 1 Operation 1 Flush With Nitrogen 5 2 Operation 2 Evacuate lines to atmosphere 6 3 Operation 3 Fill Plant With C3F8 7 4 Operation 4 Preparing for Disc Cooldown 8 4 1 Operation 4 1 Flushing with Nitrogen 2 2 2 0 20000 8 4 2 Operation 4 2 Evacuating to Atmosphere 0 0004 9 4 3 Operation 4 3 Filling with C3F8 2 aaau aaa 9 5 Operation 5 Evacuating C3F8 to Plant and Preparing For Disc Removal 10 6 Operation 6 Final Removal of C3F8 11 6 1 Operation 6 1 Removal of most of the C3F8 0 11 6 2 Operation
8. closed off volume they make the check more sensitive ATLAS Project Document No Page 5 of 12 1 Operation 1 Flush With Nitrogen Initial state Compressor off liquid pump off vacuum pump off C3F8 Plant Supply Lines and any disc circuits full of air at atmospheric pressure N bottle closed If preparing for initial C3F8 fill connect the C3F8 bottle to the schraeder valve first with the bottle valve closed Then the connecting tube is also purged with N2 and evacuated ResulComments Close V4 V5 V6 V7 Disc Box and Cylinder Box isolated from system Close V9 V11 V12 Vacuum pump isolated from system 3 Open V1 V2 V3 V10 and SV Flush circuit is open and at atmospheric pressure in C3F8 plant g Set nitrogen pressure regulator Flushing begins gently avoiding damage to flow to 0 bar anti clockwise Open meters V8 slowly raise regulator pres sure till you hear gas flowing Wait till flushed Circuit is full of dry nitrogen at atmospheric pres sure ey Close V8 then V3 immediately Flushing stops circuit is sealed after Final state The circuit is full of dry nitrogen sealed from the atmosphere Note Leak checks can be carried out by pressurising the lines via V8 with V3 closed and watching how fast the pressure drops Make sure the circuit is leak tight before proceeding ATLAS Project Document No Page 6 of 12 2 Operation 2 Evacuate lines to atmosphere Initial state Compressor off liquid pump off
9. d in the circuits only vapour at about 1 bar if HE1 is at 36 C Make sure V12 is closed and Avoid C3F8 loss and protect vacuum pump Pvac is low below 2 bar a on DCS 1 bar g on Py 7 Turn vacuum pump on Start evacuating Supply Lines and disc circuits re alpen turning C3F8 gas into C3F8 Plant Wait till Pvac is low enough be Very little C3F8 left in lines B EEE Close V11 C3F8 secured in C3F8 plant 11 Close V9 and turn off vacuum Vacuum pump isolated from circuit pump Turn off compressor C3F8 in Plant will slowly warm up and reach 6 bar 13 Open V12 slowly Supply Lines and disc circuits fill with air Open slowly to not damage flow meters by large reverse flow 14 Close any of V4 V5 V6 V7 Isolate Supply Lines from Disc and Cylinder Boxes el that were open to reduce risk of damage to Supply Lines 15 Close any valves inside Disc or Protect lines inside Boxes fey Cylinder Box to circuits Final State The disc circuits and supply lines are full of air at atmospheric pressure The C3F8 is contained in the C3F8 plant Connections to the disc can be opened e g for disc removal ATLAS Project Document No Page 11 of 12 6 Operation 6 Final Removal of C3F8 Needed for C3F8 Plant maintenance or at end of life Aim is to recover C3F8 clean and ready for re use and to minimise atmospheric pollution C3F8 is a powerful greenhouse gas These instructions are now obsolete because we have bought a specia
10. ed for disc in Disc Box V4 and V6 open V5 and V7 closed for disc in Cylinder Box V5 and V7 open V4 and V6 closed ResulComments Check Pvac system is at about Avoid putting excess pressure on vacuum pump and atmospheric pressure with dry wasting C3F8 nitrogen all valves are in correct initial state 2 Open V12 turn vacuum pump Start evacuating nitrogen from lines to atmosphere on open V9 Wait till pressure is about 1 mbar Circuit is evacuated with residual dry nitrogen 4 Close V9 turn the vacuum pump Vacuum pump is isolated from Supply Lines off close V12 Leak Check Make sure all leaks are cured before introducing C3F8 Final state lines are leak tight with about 1 mbar of dry nitrogen 4 3 Operation 4 3 Filling with C3F8 Initial state Compressor off liquid pump off vacuum pump off C3F8 Plant full of warm C3F8 at about 6 bar supply lines and disc circuits at or below 1 mbar with residual dry nitrogen unused cooling circuits in test boxes sealed off V1 V2 V3 V8 V9 V10 V11 V12 closed for disc in Disc Box V4 and V6 open V5 and V7 closed for disc in Cylinder Box V5 and V7 open V4 and V6 closed ResulComment Check pressure is below 30 mbar Avoid excess pressure on vacuum pump and avoid in DCS with all valves in correct wasting C3F8 initial state 2 Partially open V10 slowly 7 bar C3F8 to vacuum Discs fill with C3F8 flow meters fill backwards slowly via restrictors Open
11. ed pump open V9 Check bottle pressure is low Vacuum outlet prepared enough for vacuum outlet open V12 8 Turn vacuum pumpon Residual C3F8 is pumped to the bottle o Wait uill Pvac stops decreasing 10 Close bottle valve V9 and V12 As much C3F8 as possible is in the bottle turn off vacuum pump Turn off bottle chiller Bottle is ready for removal and storage 12 Open V3 Vent small quantity of C3F8 from mass flow meters Alternatively this volume could also be return to the bottle via the Disc Box evaporator by opening V4 and V6 before step 5 12 Set nitrogen regulator to just C3F8 Plant is full of nitrogen to avoid moisture in above 1 bar absolute open V8 it until circuit is just above atmo spheric pressure close V8 Slowly open V2 14 Close V10 and V2 C3F8 Plant is isolated and full of nitrogen at atmo spheric pressure ready for maintenance storage Open V4 V5 V6 V7 All lines brought to atmospheric pressure with air Final state As much C3F8 as possible is recovered into the bottle small amount vented to atmosphere C3F8 plant full of nitrogen at atmospheric pressure lines open to air Plant can be maintained or stored bottle can be stored or returned to supplier
12. l refrigerant recovery plant Follow the plant instructions instead of the following However the following is left in place until we have worked out just how to use the new recovery unit This procedure requires a C3F8 bottle either with some C3F8 in or evacuated no moisture and with a valve and pressure gauge This container has to be cooled e g by placing in a chiller and cooling to as low a temperature as reachable but not below 40 C 6 1 Operation 6 1 Removal of most of the C3F8 Initial state Compressor off liquid pump off vacuum pump off All valves closed C3F8 is in C3F8 Plant following operation 5 but OMITTING step 12 so no air is allowed into the lines Then Supply Lines are at vacuum with residual C3F8 at 1 mbar ResulComment 1 Carry out Operation 5 Evacuat Initial state check ing C3F8 to Plant and Preparing For Disc Removal but OMIT TING step 12 and check all valves are closed 2 Slowly open V2 Prepare for venting through V3 open slowly to pro tect flow meter 3 Open SV valve in C3F8 Plant By pass the liquid pump 4 Connect the C3F8 bottle to the Bottle ready to receive C3F8 vent line at V3 open bottle s valve 5 Open valve V3 If bottle was at vacuum some C3F8 gas flows in otherwise pressures in C3F8 Plant and bottle equal ize Start cooling the bottle C3F8 condenses in bottle pressure reduces in C3F8 ee 7 Wait until C3F8 in plant is at All C3F8 liquid in C3F8 Plant has evaporated r
13. oom temperature and it s pres sure is appropriate to the bottle temperature Close V3 and the valve on the Most of the C3F8 is now in the bottle bottle and disconnect the bottle Final state Most of the C3F8 is in the bottle and being kept cold by a chiller The C3F8 Plant and some of the Supply Lines contain C3F8 gas at a pressure corresponding to the temperature achieved in the bottle this may be upto 3 bar Ready for final C3F8 Recuperation ATLAS Project Document No Page 12 of 12 6 2 Operation 6 2 Recuperation of residual C3F8 gas This is only possible if the bottle can be cooled so that the C3F8 pressure in it is below the maximum pressure that the vacuum pump can handle If not either the residual C3F8 has to be vented to air or a second pump stage has to be attached to V12 so that the outlet pressure of the vacuum pump is low enough Initial state after Operation 6 1 i e compressor off liquid pump off vacuum pump off SV the liquid pump by pass and V2 open all other valves closed C3F8 bottle cold and pressure below 2 bar absolute maximum outlet pressure of vacuum pump Step Resul Comments Check inital state Safety and avoid escape of C3F8 from bottle to Plant 2 Read instruction 11 and take ap Decide if you want to also recover C3F8 from propriate action flowmeters 4 Connect C3F8 bottle to V12 vent Bottle ready to receive more C3F8 E On V10 Check Pvac is safe for vacuum Vacuum inlet prepar
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