| Lines 5-6 were replaced by lines 5-7 |
| - Handling cryogenic liquids should only be done by trained people. Fear is a bad teacher \\ |
| - and you should always consult a more experienced instrument scientist or [the sample environment team|http://lns00.psi.ch/sinqwiki/Wiki.jsp?page=SampleEnvironment]\\ |
| + Handling cryogenic liquids should only be done by trained people. The following instruction are by no means a replacement for a certified cryogenics course. They are meant as a reference for how to handle cryogenics at the Neutron guide hall. \\ |
| + Fear is a bad teacher |
| + and you should always consult a more experienced instrument scientist or [the sample environment team|SampleEnvironment], |
| At line 10 added 2 lines. |
| + For information on how to set up an orange cryostat and how to change samples, please follow this link: [OrangeCryostat|http://lns00.psi.ch/sinqwiki/Wiki.jsp?page=OrangeCryostatCooldownProcedure]. |
| + |
| Line 16 was replaced by line 19 |
| - [LN2_dewar_schematics|cl_clpb.gif] |
| + [LN2_dewar_schematics|LN2.png] |
| Lines 20-21 were replaced by lines 23-25 |
| - The filling hoses have a metallic protection sleeve. The valves and the hose get very cold during a nitrogen transfer. |
| - *Make sure that you wear protective leather gloves when handling cold parts. |
| + The filling hoses have a metallic protection sleeve. The valves and the hose get very cold during a nitrogen transfer. |
| + *Make sure that you wear protective leather gloves when handling cold parts, however the gloves should never be soaked with LN2 or LHe. |
| + |
| Line 28 was replaced by line 32 |
| - Liquid Helium dewars are provided by the sample environment staff at the sample preparation area.\\ |
| + Liquid Helium dewars are provided by the sample environment staff at the preparation area.\\ |
| Line 32 was replaced by lines 36-37 |
| - *Always measure the Helium level in the dewar before you take a Dewar away |
| + *The Level meter in the preparation area shows the level in litres. Make sure that there is sufficient helium for filling. The dewars |
| + should be returned with a level of at least 10-15 litres. |
| At line 34 added 1 line. |
| + |
| Line 37 was replaced by lines 43-52 |
| - __Helium Transfer:__\\ |
| + __Helium Dewar Transport:__\\ |
| + Helium dewars are brought into the experimental area with the 1T crane. |
| + *Only instructed people are allowed to use the crane. (A short training is offered by the LDM mechanics personal.) |
| + *Only dewars with pre-installed transport straps are allowed for crane transportation. |
| + *To extend the straps please use the proper extensions as shown in the picture below. |
| + |
| + | [transport extensions|HeDewartransport.png] | [dewar with transport fixtures|transportstraps.png] |
| + |
| + |
| + __Helium Transfer:__ |
| Line 41 was replaced by line 56 |
| - *slowly lower the siphon into the dewar observe the pressure rise in the dewar (try to stay below 0.2bar) |
| + *slowly lower the siphon into the dewar and observe the pressure rise in the dewar (try to stay below 0.2bar) |
| Lines 45-48 were replaced by lines 60-65 |
| - *continue to lower the siphon into the transport dewar until you reach the bottom and lift it up by 10 cm |
| - *switch on the compressed Helium gas line and connect the gas hose to one of the pressure release valves\\ |
| - and open it. The dewar is now pressurized to 0.2bar over pressure. |
| - When the transfer is finished:\\ |
| + *continue to lower the siphon into the transport dewar until you reach the bottom. |
| + *switch on the compressed Helium gas line and connect the gas hose to one of the pressure release valves |
| + and open it. The dewar is now pressurized to 0.15 bar over pressure. |
| + *make sure not to empty the vessel completely, the people running the liquefier will love you. On the transfer line, normally there is a prolongation with a hole at 10 cm above the end. If not, you should lift the transfer line by 10 cm after inserting. |
| + When the transfer is finished: |
| + |
| Line 51 was replaced by lines 68-69 |
| - *make sure that the extraction and filling ports are properly sealed |
| + *make sure that the extraction and filling ports are properly sealed. It might be necessary to |
| + use a hair dryer to remove the ice. |
| Line 55 was replaced by lines 73-84 |
| - |
| + !Returning Liquid Helium Dewars |
| + please return dewars to the dewar station as soon as possible after the transfer |
| + *connect the dewar to the rubber hose of the dewar station |
| + *open the manual valve to the recovery |
| + *open the manual pressure release that is connected to the recovery on the dewar |
| + *check the other manual pressure release. it MUST be closed |
| + *retighten the locking nut of the Helium extraction port |
| + *connect the level probe |
| + |
| + IMPORTANT: |
| + recheck that all valves are in the right state and the level is reading before you leave |
| + [afterfill.png] |
| At line 56 added 1 line. |
| + In case you are unsure about certain procedures, please contact sample environment staff |
LIN