A blog on the repair, operation and calibration of surface analysis systems and components including electron spectrometers, sputter ion guns and vacuum related hardware. Click on the Index tab below to see a list of all posts. Visit our website at http://www.rbdinstruments.com
The Hydraulic Quick Couplings (quick connect) used on PHI X-ray sources are Parker type SH2-62.
These couplers are used to connect the heat exchanger to the X-ray source in order to keep the anode from overheating. Over time the seals in the female coupler can fail from wear or simply drying out. When that happens you will get a steady drip of water from the coupler (not good as if water leaks into the source it will arc) .
This post will explain how to find and replace the seals in the female coupler. The male coupler is non serviceable (but also usually does not fail). Some pictures of the fitting and seals are at the bottom of this post.
There are two parts to the seal mechanism.
A Teflon seal retainer
A Nitrile O-ring seal
You can find these parts at any Parker distributor (Google Parker quick coupling) or by searching for the part numbers.
The Teflon seal retainer is PN MS28774-015
The Nitrile O-ring is PN 2-015 N1470-70
If you search for the part numbers you will find lots of places that carry these parts. They are very inexpensive. In fact, the next time you order parts from RBD for your PHI X-ray source just ask and we will throw some in with your order at no charge.
Once you have the parts, here is how you install them:
Use a dental pick and dig out the Teflon spacer and O-ring
Install the new O-ring. You can use the dental pick to guide it into the channel. Note that the O-ring needs to be towards the bottom of the coupler
Install the new Teflon spacer using the dental pick to guide it into the channel. Note that it needs to be installed towards the top of the coupler. Also, for the Teflon spacers that I purchased for this blog post, they have a slit in them which is probably supposed to make it easier to install. However, I think it would have been easier with a solid spacer like the old one I pulled out. It was a little bit tricky but by using a screw driver I was able to flatten the slit so that it finally snapped down into the channel. You should plan on losing one or two of the Teflon spacers as you refine you technique.
Finally, here is a link to a the Parker Hydraulic Quick connect catalog – 3800-B_Hydraulic.
The Hastings RV-16D thermocouple vacuum gauge is used in the Physical Electronics’ (PHI) Auto Valve Control (AVC) to read the vacuum in the load lock and also at the turbo pump. There are two DV-6M thermocouple sensor tubes connected to the back of the AVC and a relay selects which one is routed to the RV-16D vacuum gauge.
The 0 to 10mV output of the RV-16D (also called the “Hockey Puck” ) goes to a comparator circuit in the AVC and is ultimately displayed on a LED segment graph on the AVC remote. One bar on the AVC remote indicates up to air and 5 bars indicates less than 5 X 10-3 Torr.
When the Hockey Puck in the AVC fails, it is usually because one of the DV-6M thermocouple sensor tubes failed and in turn some of the resistors inside the RV-16D overheated. This blog post will show you how to repair the RV-16D by replacing those failed resistors with higher wattage ones that should be able to survive the next time one of the DV-6M gauges fail.
The layout and schematic below show the resistors that usually fail. R 3 is a 15K ohm 2 watt resistor and R 4 is a 100 ohm 1/2 watt resistor.
Failed Resistors on RV-16D
Failed Resistors on RV-16D schematic
It is recommended that when you replace these resistors that you increase the wattage. For the repairs in the photos below, I used a 15K ohm 5 watt resistor and a 100 ohm 2 watt resistor. These resistors are readily available from Digikey, Newark and Mouser.
And since I already had the RV-16D torn apart I also replaced the capacitor C1 with a new one.
TC gauge before repair
TC gauge after repair
When working on the RV-16D be sure to completely unplug the power to the AVC. I recommend pulling the AVC completely out of the electronic rack or vacuum console. The RV-16D is located in the back left hand corner of the AVC. If your RV-16D has the metal cover on it you will need to remove it and either cut it around the wires or un-solder the wires an feed them through the case. Use your cell phone and take some pictures for reference before you un-solder any wires so that you can be sure to put them back in the exact same place. You do not need to replace the cover, the RV-16D will run cooler without it.
One final note. The schematic is not 100% correct as there is a 49 ohm resistor that is tied across the output on most of the RV-16D gauges that I have pulled apart. I think that this resistor replaces R5 and R6 as R6 is not needed since only the 10mV recorder output is used in the PHI AVC. If your RV-16D does not have the 49 ohm resistor, then I recommend that you add one. It will help to stabilize the output.
49 ohm resistor
If you need technical assistance or parts for the AVC or replacement DV-6M tube please contact us by creating a sales ticket here – RBD Portal Sales
Since the AVC was out anyway, I replaced the pots from the RV-16D (R1 , 1 K ohm) and also the bar adjustment pot in the AVC ( R 103 / K6 25 K ohm) to the AVC front panel with 10 turn 2 watt precision potentiometers and also installed an isolated BNC connector to the RV-16D recorder output wires (Blue and black).
This modification makes it much easier to adjust the RV-16D recorder output when you install a new DV-6M tube and to adjust the AVC for 4 bars when the load lock is pump out. The 5th bar on the AVC remote is on a timer and will turn on after the 4th bar stays on for 2 minutes.
With this modification installed it is not necessary to remove the AVC cover to adjust the hockey puck output or the AVC 4th bar.
Installing repaired TC gauge into AVC
Repaired TC gauge inside AVC
10mV and 4th bar
Soldering wires to front panel 10mV and 4th bar potentiometers
The Auto Valve Controller (AVC) is used to open and close valves on PHI surface analysis systems such as the 5000 series XPS and 660 scanning Auger systems. The AVC has a small built in microprocessor and so it also has the ability to protect the user from inadvertently opening a valve out of sequence and dumping the system.
The AVC needs to know that the turbo pump is on before certain valve functions are available. For example the V4 ion gun differential pump valve will not open under any circumstance if the turbo pump is not on.
So, how does the AVC know that the turbo pump is on? The Up to Air relay in the AVC auto valve controller is energized by a voltage from the turbo pump controller.
Up to Air relay inside AVC
When the AVC was designed PHI used Balzers (now Pfeifers) turbo pumps which had a 240 VAC output voltage when the turbo pump controller was ON. So, the Up to Air relay in most AVCs has a 240VAC coil.
Fast forward to today and some of those original Balzers/Pfeifers turbo pumps and controllers are now obsolete. So when one of those controllers fails, it needs to be replaced with a new state of the art turbo pump and controller.
These days most turbo pump controllers have a 24 V DC output voltage that can be used to control the AVC up to air relay. Both Edwards and Pfeifers have low cost replacement packages that are 4.5” CF flange mounted and also dry pumped backed. See information on those pumps at the bottom of this post.
The direct replacement 24 V DC Up to Air relay is Grainger part number 1YCZ6. This relay is the same form factor as the original Up to Air relay only it has a 24V DC coil instead of a 240 VAC coil.
24V up to air relay
Updating an AVC to this relay is a simple two-step process;
Replace the Up to Air relay in the AVC
Connect the Up to Air cable to the new turbo pump controller.
To replace the Up to Air relay in the AVC first make sure that all valves are closed and that the turbo pump is OFF.
Turn OFF the AVC and also unplug the power from the back of the AVC control. Depending on your system configuration the AVC is located in the front left hand side of the electronics console, or in the back of the vacuum console.
If the solenoid manifold is located on top of the AVC, remove the screws that hold the manifold to the cover and then remove the cover from the AVC. You should be able to move the solenoid manifold towards the back of the AVC and not need to unplug the wire bulkhead connector. Just balance the manifold on the edge of the AVC chassis.
If your AVC has the solenoid manifold mounted on the back of the AVC, then just remove the AVC cover.
Slide the AVC out enough so that you can get at the screws which mount the Up to Air relay to the side of the AVC. The Up to Air relay is located on the right hand side of the AVC chassis.
Make a drawing or use your phone and take a picture of the connections to the Up to Air relay to make sure that you put the connectors on the same way when you install the new relay. Remove the 240 VAC Up to Air relay bracket and install the new 24V DC relay.
Reattach the relay bracket to the side of the AVC.
Reattach the cover and solenoid manifold.
Reattach the power cord and slide the AVC back in.
Next, you need to attach the Up to Air cable to the new turbo pump controller. Refer to the turbo pump manual for information on how to make that connection. There will be a Setpoint output or some kind of external status connection that provides 24V DC when the turbo pump is ON.
Note the polarity of the wires on the Up to Air cable. On the end that plugs into the back of the AVC, the larger connector is the negative (ground) wire and the smaller one is the positive (+24V) connector. There are only two wires in the Up to Air cable. Red is positive and Black is ground.
If your turbo pump controller has some other voltage for the status signal (such as 12V or 5 V DC) then you will need to find a version of the Up to Air relay with that same voltage.
Once the new Up to Air relay modification is complete then you should hear the V5 vent solenoid click when the turbo pump is turned ON.
The V5 vent valve is designed to vent the turbo pump in order to prevent back-streaming of oil vapors into the system in the event of a system dump. When the AVC was first designed the backing pumps were all rotary vane mechanical pumps that used oil.
New state-of-the-art turbo pumps are typically backed with a dry pump and also have built in vent valves. If your new turbo pump is also dry backed (both of the turbo pumps listed below are then you do not need the V5 vent function.
The V5 vent valve was mounted on the rough side of the old turbo pump. If your new turbo pump is dry backed all you need to do to disable the V5 vent valve is to close the little needle valve that is either on the V5 vent valve itself or on the solenoid manifold near the V5 vent solenoid. (The largest solenoid is V1 and then you count out from there, V2, V3….)
If your new turbo pump is backed with a rotary vane oil pump then the V5 vent valve still needs to be connected to the rough line. The V5 needle valve is set to 1/4 turn CCW from the fully closed (full CW) position.
In addition, you want to make sure that the mechanical pump turns OFF when the turbo pump is turned OFF. If you need help with that contact RBD Instruments.
The affordably priced turbo pumps below can replace the original Balzers TPU 040 thru TPU 062 turbo pumps on older PHI surface analysis systems. If you order one, make sure that you order it with a 4.5” CF flange. A 4.5” CF flange will make it easier to adapt the new turbo to the existing vacuum connections.
If you get one of the Pfeiffer Cubes then this is the cable that you will need to connect to the Up to Air connector on the back of the AVC – Digikey PN A120881-ND made by TE and the TE PN is 22730001-1