All work performed by the Central California 900 MHz Facility should be acknowledged in reports, presentations, posters, papers, and other publications. Your acknowledgment is a measure of our facility’s impact, and is essential to our funding and continued operation.
Please acknowledge funding as follows:
Funds for the 900 MHz NMR spectrometer were provided by the NIH through grant GM68933.
Please also let us know if you report or publish data using the 900 MHz instrument by sending an e-mail to qb3nmr@berkeley.edu.
Please also link your papers to our NIH grants in eRA commons, RePORTER, etc., through myNCBI. Instructions on how to do so can be found here.
| Helium | 500 | 600 | 700 | 800 | 900 |
| Refill He Level | 39% | 60% | 61% | 35% | 45% |
| Refill Volume | 26L | 40L | 250L | 150L | 250L |
| Min He Level | 5% | 40% | 45% | 5% | 5% |
| Lowest observed | 22% | 56% | 22% | 35% | |
| Boiloff %/day | 1.3% | 0.76% | 0.29% | 1.57% | 1.46% |
| Hold Time | 55 d | 47 d | 120 d | 58 d | |
| Max Fill Volume | 40 L | 56L | 317L | 241 L | |
| Liters / Percent (Actual for fill) |
0.4 | 1.08 | 6.6 | 2.9 | 4.55 |
| Boiloff %/day | 1.3 | 0.76 | 0.29 | 1.57 | 1.46 |
| Nitrogen | 500 | 600 | 700 | 800 | 900 |
| Boiloff %/day | 5.1 | 4.75 | 4.6 | ||
| Max Fill Volume | 86L | 135L | 365L | 232L | |
| Hold time | 17.5d to 10% | 18d to 15% | > 21d | 18d to 15% | >21d |
Assume 86% transfer efficiency for helium transfer from dewar.
250 Lt will fill the following:
- 500 from 39% to 100%
- 600 from 63% to 100%
- 800 from 35% to 95%
250 Lt will fill the 900 from ~45 % to 100%
Cryogen fill parameters
Standard Operating Procedure
Use of liquid nitrogen filling station
Date: 02-12-13
SOP Title: Use of liquid nitrogen filling station
Room and Building: B304B – Stanley Hall
| Section 1 | Process |
| Filling of liquid nitrogen dewars from automatic fill station located in B304B. | |
| Section 2 | Hazardous Chemicals |
| Liquid Nitrogen | |
| Section 3 | Potential Hazards |
| Liquid cryogens pose a potential asphyxiation hazard. Nitrogen expands by a factor of 680
and helium expands by a factor of 740 when changing from the liquid to gas phase. The expanding gas displaces breathable oxygen. To limit the asphyxiation hazard, liquid nitrogen and liquid helium should only be handled in well-ventilated areas. Immediately evacuate the room if an oxygen sensor audible alarm sounds. The extreme cold of liquid nitrogen and helium can cause oxygen to condense from the air, resulting in fire danger. Keep cryogen use areas free of combustible materials (paper, cardboard, machine oil, etc) and eliminate any other sources of ignition. |
|
| Section 4 | Approvals Required |
| Wemmer group members must be trained by Jeff Pelton and sign the SOP. | |
| Section 5 | Designated Area |
| Fills are to occur in Rm B304B. | |
| Section 6 | Special Handling Procedures and Storage Requirements |
| None | |
| Section 7 | Personal Protective Equipment |
The main hazards associated with handling liquid nitrogen and liquid helium are: A) burns when the skin comes into contact with cold pipes or liquid, and b) asphyxiation if nitrogen or helium has expanded from its liquid form and the gas has displaced oxygen. To reduce the potential for injury, follow these guidelines:
expanding gas could fill the elevator and pose a serious risk of asphyxiation.
|
|
| Section 8 | Engineering/Ventilation Control |
| The door to B304B into B304 should remain open during the fill in order to provide adequate ventilation. | |
| Section 9 | Spill and Accident Procedures |
| In case of a liquid nitrogen spill, provide plenty of ventilation and wait for the liquid to vaporize. | |
| Section 10 | Waste Disposal |
| No waste is generated | |
| Section 11 | Decontamination |
| None | |
| Section 12 | Process Steps | ||
|---|---|---|---|
| Process steps | Safety Measures | ||
| Attach liquid line to liquid port on dewar | Wear a face shield and gloves | ||
| Attach vent line to vent port on dewar | |||
| Fully open vent and liquid valves on dewar | |||
| Pull the red “STOP” botton out to “on” position | Push the red STOP button in the halt the fill | ||
| Press the fill button and hold for several seconds | |||
| After the fill is complete, close the liquid and Vent valves on the dewar. | |||
| Disconnect the hose at the vent port of the dewar | Wear a face shield and gloves | ||
| Disconnect the hose at the liquid port of the dewar Do this slowly and beware that cold gas trapped in The line will escape | Wear a face shield and gloves | ||
| Troubleshooting | |||
| If the filling light turns off after releasing the fill Button, the system isn’t sensing the proper pressure. Check the connections and make sure that both valves are open and connected in the right orientation – Vent to vent and liquid to liquid. | |||
Standard Operating Procedure
Filling the 500/600/800/ and 900 MHz magnets with liquid nitrogen
Date: 02-12-13
SOP Title: Filling 500.600.800, and 900 MHz magnets
Room and Building: B304 – Stanley Hall
| Section 1 | Process |
| Filling of liquid nitrogen for the 500, 600, 800, and 900 MHz magnets | |
| Section 2 | Hazardous Chemicals |
| Liquid Nitrogen | |
| Section 3 | Potential Hazards |
|
|
| Section 4 | Approvals Required |
| Wemmer group members must be trained by Jeff Pelton and sign the SOP. They must also take the UC Berkeley on-line Cryogens Safety course. | |
| Section 5 | Designated Area |
| Fills are to occur in Rm B304B. | |
| Section 6 | Special Handling Procedures and Storage Requirements |
| None | |
| Section 7 | Personal Protective Equipment |
The main hazards associated with handling liquid nitrogen and liquid helium are: A) burns when the skin comes into contact with cold pipes or liquid, and b) asphyxiation if nitrogen or helium has expanded from its liquid form and the gas has displaced oxygen. To reduce the potential for injury, follow these guidelines:
expanding gas could fill the elevator and pose a serious risk of asphyxiation.
|
|
| Section 8 | Engineering/Ventilation Control |
| None | |
| Section 9 | Spill and Accident Procedures |
| In case of a liquid nitrogen spill, provide plenty of ventilation and wait for the liquid to vaporize. In the event of a fire alarm, turn off the liquid flow. Leave hoses connected. Leave the building. | |
| Section 10 | Waste Disposal |
| No waste is generated. | |
| Section 11 | Decontamination |
| None | |
| Section 12 | Process Steps | ||
|---|---|---|---|
| Process steps | Safety Measures | ||
| Identify either the 250 Lt or 100 liter dewar in Room B304B. | Wear a face shield, goggles, and gloves | ||
| Identify polypropylene tubing on concrete block in Center of B304. | |||
| Identify brown (Cu/Be) non-magnetic wrench kept On the concrete block in B304. | |||
| Roll dewar over to magnet. | |||
| Attach polypropylene tubing to liquid port of dewar | A mistake is to connect the tube to the vent port.
Only use a non-magnetic (brown) wrench! |
||
| Remove the safety release cover to the magnet | For the 800, also remove the tube attached to the vent port. Not required for the 500/600/900. | ||
| Fill Port | |||
| Attach other end of tubing to the fill port of the Magnet. | |||
| Slowly open valve to the liquid port – approx ¼ open | |||
| Wait approximately 3 minutes for the tubing to cool. | |||
| Continue to open port to approximately ½ open | |||
| Fill liquid nitrogen until it comes out of the vent ports. | |||
| Once full, close the liquid port valve. | |||
| Allow approximately 5 minutes for the tubing to warm | |||
| Disconnect the tube from the magnet. | Only use a non-magnetic (brown) wrench. | ||
| Use the brown non-magnetic wrench to disconnect the tube from the dewar. | |||
| Re-attach safety release valve to magnet fill port. For the 800, also re-attach the vent tubing. | It is easy to forget to replace the safety release Valve. | ||
Click here for Training Documentation and nitrogen fills pdf.
Principle investigator: David E. Wemmer
Room and Building: B304 Stanley Hall
Lab phone number: 510-666-2753
Process
Filling 500 and 600 MHz systems with liquid helium. Needed approximately every 6 weeks.
Hazardous chemicals
Liquid helium and compressed helium gas
Potential hazards
- Liquid cryogens pose a potential asphyxiation hazard. Nitrogen expands by a factor of 680 and helium expands by a factor of 740 when changing from the liquid to gas phase. The expanding gas displaces breathable oxygen. To limit the asphyxiation hazard, liquid nitrogen and liquid helium should only be handled in well-ventilated areas. Immediately evacuate the room if oxygen senor audible alarm sounds.
- The extreme cold of liquid nitrogen and helium can cause oxygen to condense from the air, resulting in fire danger. Keep cryogen use areas free of combustible materials (paper, cardboard, machine oil, etc) and eliminate any other sources of ignition.
- Only use non-magnetic wrenches when working with magnets. Steel or other ferromagnetic tools may be sucked into or against the magnet causing equipment damage and/or bodily injury.
Approvals required
Wemmer group members must be trained by Jeff Pelton and sign the SOP. They must also take the UC Berkeley on-line Cryogens Safety course
Designated area
Fills are to occur in Rm B304 2
Personal protective equipment
The main hazards associated with handling liquid nitrogen and liquid helium are A) burns when skin comes into contact with cold pipes or liquid, and b) asphyxiation if nitrogen or helium has expanded from its liquid form and the gas has displaced oxygen. To reduce the potential for injury, follow these guidelines:
- Avoid contact with cold unprotected pipes and vessels when working with liquid nitrogen or liquid helium.
- Wear proper protective equipment:
- Dry leather or cryogenic gloves must be worn to avoid cold burns. The gloves must be loose fitting so that they can be removed easily.
- Safety glasses and face shield must be worn to protect the eyes and face.
- Wear close-toed shoes and long pants while handling cryogens to protect feet and legs from accidental spills.
- Wear a lab coat or a heavy, loose-fitting jacket or fleece to protect your arms.
- Metallic objects (e.g. jewelry) should be removed from those parts of the body that may come into contact with the liquid.
- Never accompany cryogens in the elevator. If the elevator were to malfunction, the expanding gas could fill the elevator and pose a serious risk of asphyxiation. Load dewar on the elevator, post the “No Passengers” sign on the dewar, and retrieve it after using a separate route (stairs or another elevator).
- When transferring cryogenic liquids, always direct the flow away from others.
Engineering and ventilation control
None
Process steps
Routine fills.
250 L will fill the 500 (from 30%), 600 (from 65%), and 800 (from 35%).
The 500 is usually filled first, followed by the 600 and 800. 250 L will fill the 900 from 45%.
Note the fill volumes and minimum helium levels for each system on the plastic enclosed sheet near the SOPs.
Two people are recommended if they are new to the procedure.
Step 1. Prepare the dewar.
Locate the He transfer line, which is kept on the cement cylinder block in the center of Rm B304. Locate and attach the brass Goddard fitting to the top of the dewar. These are usually kept on top of the console to the 700. If not, check if they are on the Pines’ group transfer line near the 700. If you can’t find it, ask someone from the Wemmer or Pines labs for help. Make sure you have all three pieces of the Goddard fitting – ie make sure the He transfer line can be inserted into the fitting with a tight seal. If not, you are probably missing the top most Goddard fitting.
Attach the helium gas line to the vent port of the dewar. The fitting and plastic hose are kept on the floor in a green plastic bin to the right of the nitrogen fill room. Attach the gas regulator to the He gas cylinder within the nitrogen fill room. Attach the hose to the regulator. Do not start the flow of gas at this time.
An alternative to using the He gas cylinder to pressurize the dewar, is to use the built-in heater that comes with all of the 250 L He dewars. A yellow extension cord is located I the green bin along with the He gas hose, fitting, and regulator. The extension cord should be plugged into a 120 V outlet and the heater plug at the top of the magnet. The settings are for 4 and 8 psi. Even 4 psi is too much, but you can turn the heater on and off to maintain about 3 PSI pressure.
Step 2. Prepare the magnet.
Remove the brass one-way valve at the top of the magnet and insert a crumpled-up paper towel so that air cannot enter the helium reservoir of the magnet.
Loosen the black He fill port at the top of the magnet. To loosen the plug, partially unscrew the fitting just below the plug.
Step 3. Cool the He transfer line and begin the fill Close the vent valve on the dewar.
Close the pressure release valve on the dewar.
One person should be on a step ladder close to the He fill port, and a second person should be close to the He dewar. The person close to the He dewar should slowly insert the long end of the transfer line into the He dewar about one-half way. Helium gas should exit the short end of the transfer line. Allow the cooling process to continue unti a plume is apparent at the short end of the transfer line.
The person close to the dewar should open the pressure release valve while the person close to the magnet removes the black fill port plug and inserts the short end of the transfer line into the magnet. Note that the long end of the transfer line might need to be raised somewhat in order to create enough length to insert the short end into the magnet. The paper towel usually pops out due to the increased pressure. If not, remove the paper towel to allow He gas to escape.
Slowly insert the transfer line until it hits the bottom of the dewar, and then raise it one-half inch.
Step 4. Pressurize the dewar and continue fill.
Helium gas is used to pressurize the He dewar and to “push” liquid helium from the dewar and into the magent.
Open the vent port on the dewar (with the hose attached). Open the He gas cylinder valve to start the flow of liquid helium. Use the secondary valve at the regulaor to keep the flow rate low. Pressure in the He dewar should not exceed 4 PSI. If it exceeds 4 PSI, close the He gas cylinder and continue the fill, until the pressure is reduced.
Alternatively, use the built-in heater that comes with 250 L dewars, as described above. Most 100 L dewars do not come with heaters.
Step 5. Monitor the fill.
After a few minutes, monitor the progress of the fill by checking the liquid helium level at the BSMS, which is located at the console (used for shimming). Note that the level on the 500 gets stuck at about 80 percent for a period of time. Once the magnet fills past 80%, the meter will read the correct value. Continue the fill until the level reaches 95% or until a plume is observed at the magnet vent port.
Also, continue to monitor the pressure in the He dewar (less than 4 PSI) and monitor the amount of He gas remaining in the gas cylinder.
Step 6. Stop the transfer
Close the valve to the He gas cylinder, to stop the pressurization of the magnet.
Open the He dewar pressure release valve to reduce the pressure in the dewar.
The person at the magnet and the person at the dewar should both remove their end of the transfer line simultaneously.
Step 7. Close magnet and dewar
Close the top valve of the He dewar. Also be sure that the vent valve is closed and that the pressure release valve is OPEN. The pressure release valve must remain open while not being used to prevent overpressure of the He dewar, due to evaporating liquid helium.
Quickly re-attach the one-way valve and black He fill port plug on the magnet.
Remove the He gas line and gas line fitting from the He dewar.
Remove the Goddard fitting from the dewar. Two hours after the fill, retighten the connection on the one-way vent valve and the plug on the He fill port.
Troubleshooting:
- If the outside jacket of the transfer line is cold, stop the transfer. The vacuum in the line was probably lost. If the vacuum is completely lost it will not be possible to transfer liquid into the magnet. The result is blowing He gas over the liquid He in the magnet, which boils off the remaining liquid – meaning that the He level will actually decrease! Ask the Pines group to borrow their He transfer line for the 700. It will work in both the 500 and 600. The transfer lines for the 800 and 900 are interchangeable. Either line can be used to fill either magnet.
- The He dewar won’t pressurize using the gas cylinder. One possibility is a leak at a connection. The other possibility is that there is no more liquid He in the dewar. Stop the transfer and order more liquid He.
Filling the 500 and 600 MHz magnets with liquid helium.
Principle investigator: David E. Wemmer
Room and Building: B304 Stanley Hall
Lab phone number: 510-666-2753
Process
Filling 500 and 600 MHz systems with liquid helium. Needed approximately every 6 weeks.
Hazardous chemicals
Liquid helium and compressed helium gas
Potential hazards
- Liquid cryogens pose a potential asphyxiation hazard. Nitrogen expands by a factor of 680 and helium expands by a factor of 740 when changing from the liquid to gas phase. The expanding gas displaces breathable oxygen. To limit the asphyxiation hazard, liquid nitrogen and liquid helium should only be handled in well ventilated areas. Immediately evacuate the room if oxygen senor audible alarm sounds.
- The extreme cold of liquid nitrogen and helium can cause oxygen to condense from the air, resulting in fire danger. Keep cryogen use areas free of combustible materials (paper, cardboard, machine oil, etc) and eliminate any other sources of ignition.
- Only use non-magnetic wrenches when working with the magnets. Steel or other ferromagnetic tools may be sucked into or against the magnet causing equipment damage and/or bodily injury.
Approvals required
Wemmer group members must be trained by Jeff Pelton and sign the SOP. They must also take the UC Berkeley on-line Cryogens Safety course
Designated area
Fills are to occur in Rm B304
Personal protective equipment
The main hazards associated with handling liquid nitrogen and liquid helium are: A) burns when skin comes into contact with cold pipes or liquid, and b) asphyxiation if nitrogen or helium has expanded from its liquid form and the gas has displaced oxygen. To reduce the potential for injury, follow these guidelines:
- Avoid contact with cold unprotected pipes and vessels when working with liquid nitrogen or liquid helium.
- Wear proper protective equipment:
- Dry leather or cryogenic gloves must be worn to avoid cold burns. The gloves must be loose fitting so that they can be removed easily.
- Safety glasses and a face shield must be worn to protect the eyes and face.
- Wear close-toed shoes and long pants while handling cryogens to protect feet and legs from accidental spills.
- Wear a lab coat or a heavy, loose-fitting jacket or fleece to protect your arms.
- Metallic objects (e.g. jewelry) should be removed from those parts of the body that may come into contact with the liquid.
- Never accompany cryogens in the elevator. If the elevator were to malfunction, the expanding gas could fill the elevator and pose a serious risk of asphyxiation. Load dewar on elevator, post “No Passengers” sign on the dewar, and retrieve it after using separate route (stairs or another elevator).
- When transferring cryogenic liquids, always direct the flow away from others.
Engineering and ventilation controls
None
Process steps
See schematic attached to the end of the process.
Routine fills.
250 L will fill the 500 (from 30%), 600 (from 65%), and 800 (from 35%).
The 500 is usually filled first, followed by the 600 and 800.
250 L will fill the 900 from 45%.
Note the fill volumes and minimum helium levels for each system on the plastic enclosed sheet near the SOPs.
Step 1. Prepare the dewar.
Locate the He transfer line. Both the 800 and 900 have their own transfer lines, which are located on their respective platforms. Note that each transfer line is in two parts. The short part is inserted into the magnet. The longer part is inserted into the dewar.
Locate and attach the brass Goddard fitting to the top of the dewar. These are usually kept on top of the console to the 700. If not, check if they are on the Pines’ group transfer line near the 700. If you can’t find it, ask someone from the Wemmer or Pines labs for help. Make sure you have two pieces of the Goddard fitting – ie make sure the He transfer line can be inserted into the fitting with a tight seal. The diameter of the transfer lines for the 800 and 900 are larger than for the 500/600. Thus, you only need the two biggest rings of the Goddard fitting.
Attach the helium gas line and brass fitting to the vent port of the dewar. The fitting and plastic hose are kept on the floor in a green plastic bin to the right of the nitrogen fill room. Attach the gas regulator to the He gas cylinder within the nitrogen fill room. Attach the hose to the regulator. Do not start the flow of gas at this time.
An alternative to using the He gas cylinder to pressurize the dewar, is to use the built-in heater that comes with all of the 250 L He dewars. A yellow extension cord is located I the green bin along with the He gas hose, fitting, and regulator. The extension cord should be plugged into a 120 V outlet and the heater plug at the top of the magnet. The settings are for 4 and 8 psi. Even 4 psi is too much, but you can turn the heater on and off to maintain about 3 PSI pressure.
Step 2. Prepare the magnet.
Remove the black fill plug at the top of the He fill port of the magnet. To loosen the plug, partially unscrew the fitting just below the plug.
Insert the longer end of the transfer line (A) into the port and tighten the seal by turning the fitting just below the port.
Open the short end of the transfer line for a few seconds to purge the line of air, then close it back up.
On the 900, remove the stainless steel cap at the end of the (gold) 20 psi pressure release valve. Do not remove the gold release valve.
On the 800 there are two gold release valves. Remove the first one but not the second one.
Step 3. Cool down the transfer line.
The long part of the transfer line should extend from the platform down to the dewar.
At the magnet end of the long part of the helium transfer line, make sure that the valve (twist type) is closed. Note that it operates opposite to normal convention. Turn it right to close, and left to open. The vent valve and pressure release valve on the dewar should be closed.
Insert the long end of the transfer line into the He dewar. Go down about one-half of the way, and check that the pressure in the dewar is increasing. Note that no He gas should escape from the dewar during this procedure.
Step 4. Cool down the long part of the transfer line and begin the fill
Purge the magnet end of the long part of the transfer line by removing the protective cover. Open the valve slowly. Allow He gas to escape from the line. Continue until a large plume emerges from the line – essentially meaning that liquid He is emerging and evaporating.
Close the valve on the transfer line and open the port on the short transfer line, insert line the tip of the long transfer line into the short transfer line and tighten the locking bolt.
Reduce the pressure in the He dewar (to about 3 psi) by temporarily opening the relief valve. Then open the valve on the transfer line, and begin the transfer. Note that opening and closing works opposite to convention. Gas should escape from the 20 psi relief valve.
After a few minutes push the long end of the transfer line to the bottom of the dewar, and then up one-half inch.
Monitor the pressure in the liquid He dewar. Once the pressure goes down to 2 psi, begin pressurizing the dewar with the He gas from the cylinder. To do this, open the gas vent valve on the He dewar, and then adjust the He regulator to get the right amount of gas flow. It often requires many adjustments during the fill. Keep the pressure in the dewar low – at about 3 psi. If the pressure rises to 4 psi or more, open the relief valve for a moment.
Another thing to monitor is the percentage of liquid He in the magnet. Do this at the workstation. On the BSMS (shim panel) hit the (second) and He level buttons one after the other. After a few seconds, it will report back on the He level in percent. The fill is complete when the meter reads 95% to 100%, or you hear a swoosh, meaning that the dewar is empty.
Step 5. Stop the fill.
Close the main valve on the He gas cylinder, which stops pressurization of the dewar. Also close the He regulator to stop the gas flow.
Depressurize the He dewar by opening the pressure release valve. He gas should escape from the dewar.
At the magnet, close the valve on the He transfer line to stop the flow of liquid He.
Uncouple the two transfer lines, and plug and close transfer line A. Quickly loosen the fitting below the insert point to the transfer line A and pull the transfer line – quickly out of the magnet. Insert the black plug and retighten the fitting. If not pulled out quickly enough, the short transfer line can get stuck – ie. Freeze part way up. If this happens, simply tighten the fitting, and let the transfer line and fitting warm up for 30 minutes. Then try to remove it again.
- For the 900, replace the stainless steel cap on the 20 psi relief valve.
- For the 800, replace the gold one-way valve. Make sure the flow arrow is pointed away from the magnet.
At the He dewar, pull the long end of the transfer line out and place it on the platform and close the top port/valve on the dewar. Be sure that the pressure release valve is open – to keep the pressure in the dewar low. Remove the He gas fitting and hose and close the vent port of the dewar.
Troubleshooting:
- If the outside jacket of the transfer line is cold, stop the transfer. The vacuum in the line was probably lost. If the vacuum is completely lost it will not be possible to transfer liquid into the magnet. The result is blowing He gas over the liquid He in the magnet, which boils off the remaining liquid – meaning that the He level will actually decrease! Ask the Pines group to borrow their He transfer line for the 700. It will work in both the 500 and 600. The transfer lines for the 800 and 900 are interchangeable. Either line can be used to fill either Tuesday, February 12, 2013 magnet.
- The He dewar won’t pressurize using the gas cylinder. One possibility is a leak at a connection. The other possibility is that there is no more liquid He in the dewar. Stop the transfer and order more liquid He.
Filling the 800 and 900 MHz magnets with liquid helium.