Replacing the water lines in a 16-050 heat exchanger

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In a previous post we showed you how to remove dust from the radiator in a 16-020 or 16-050 X-ray source heat exchanger

For this post we will replace the flow switch, which is used in a 16-050 heat exchanger, and also replace all of the water lines.  The water lines in this particular heat exchanger have become green with contamination from long term corrosion of the fittings and copper X-ray source anode.

We will  remove the motor and pump as part of the hose replacement procedure  and will also clean and lubricate the pump to motor connection.

This procedure will take about 2 hours.   The replacement hose should be clear reinforced braided tubing that is 5/8” OD and 3/8” ID. This type of hose is available from Home Depot, McMaster-Carr, and Grainger. Measure the length of the existing water lines and then add another 10 feet for the16-050 lines.  You may be able to get by with 50 feet but a100 foot roll at Home Depot is only about $50.00.

 

 

 

 

 

You will also need 3 gallons of distilled water from a grocery store

First of all, drain as much water as possible out of the water lines. Here is the best way to do that –

Turn OFF the 16-050 OFF and also unplug the power cord from the back of the system. Remove the top cover on the 16-050 and also remove the electrical cover that is located in front left hand corner of the 16-050.

Locate the Crydom Power On relay under the switch cover.

Double check that the power cord to the 16-050 is unplugged.

Move the black output wire from pin one to pin two. Both black output wires should be on pin two.

move wire from here

move wire from here

 

 

 

 

 

 

move wire to here

move wire to here

 

 

 

 

 

 

 

 

Remove the quick disconnects from the X-ray source and plug them into the ends of the IN and OUT water lines that connect to the 16-050.  That way, when you turn on the 16-050 one line will have water coming out and the other one will have air going into it.

Plug the 16-050 power cord back in. Hold the water lines over a water tight pail (a plastic garbage container will work well). When you turn the 16-050 switch  back ON, the water will flow out of the end of the water lines.

Turn the switch breaker OFF when the water stops flowing and is mostly spurting air.

(Note, if you have a 16-020 heat exchanger move the Pump power cord to the HV receptacle and the you can control the pump by turning the circuit breaker ON and OFF)

Unplug the 16-050 power cord.

Remove the side covers on the 16-050.

Remove the DI cartridge and water filter. Note the position of the cartridges so that you can replace them in the same locations later.

Remove the pump from the motor (one screw and a clamp) and set it aside. You do not need to disconnect the wires.

Remove the fan (the outer screws in the square metal fan support).

Next, remove the radiator.

Clean the radiator by flushing it with some Alconox or other detergent followed by a thorough rinse out with warm water.

Clean the cooling fins as needed.

Reinstall the radiator

Replace all the water lines one at a time.  Remove a line by unscrewing the hose clamps and twisting the hose off the connector.  If the connector has barbs on it you will need to cut a slit in the hose with a box cutter or utility knife.  Use the old hose section to measure the length of replacement hose then cut the new hose to the same length. Feel free to make the new hoses slightly shorter or longer if that will make it fit better.

Also, to soften the line and make it easier to slide over a barbed connector, dip the line in Acetone for about 20 seconds.  This works quite well.   You could also heat the line with a heat gun on the low heat setting for a few seconds.

When you get to the flow switch,  unscrew the two front panel screws and pull the flow switch away from the fort panel.  If you are going to replace the flow switch, now is the time.  You may need to pull some blanking plugs off of the old flow switch.  Make sure that you put the new flow switch on exactly  the same way that the old one comes off as that is very important for the water flow direction.  Take a picture with your phone before you remove the lines for reference.   Also note the location of the wires in the terminal strip.

Note that the 220VAC version of the flow switch is no longer made and so in a 16-050 you would also need a 220VAC to 120VAC step down transformer. Contact RBD Instruments if you need a replacement flow switch.

Step down transformer mounted in 16-050

Step down transformer mounted in 16-050

 

 

 

 

 

 

 

 

 

 

terminal strip

terminal strip

 

 

 

 

 

 

 

16-050 schematic

16-050 schematic

 

 

 

After all of the water lines have been replaced, remove the quick disconnects from the water lines and plug the water lines together.

Reinstall the DI and water filter cartridges.  You should replace both the De-ionizer and filter cartridges if it has been a while (a few years) since the last time you replaced them.  If you replaced the x-ray anode in a 10-610 mono source as part of this maintenance then the deionizer cartridge MUST be replaced. Contact RBD Instruments if you need a deionizer cartridge or water filter.

Reinstall the motor.

Inspect the water pump and clean and lubricate (with grease) as necessary.   The  motor to pump connection can get a lot of debris and some rust accumulation.

Reattach the pump to the motor.

Put one gallon of fresh distilled water (from a grocery store, not lab DI) into the reservoir.

Plug in the 16-050 power cord.

Turn on the 16-050.

Immediately add another gallon of fresh DI water into the resistor as the water will be filling the lines and cartridges.

Check for leaks and tighten hose clamps as needed.

Add more water as needed until the level is correct on the back of the 16-050.  It will take 3 to 3.5 gallons.  Give it some time for the cartridges to fill up, about 10 to 15 minutes before you do a final top off.

If you have replaced the flow switch you can monitor pins 1 to 5 on the Coolant ON/OFF connector with an ohmmeter. With the 16-050 on and water flowing, adjust the potentiometer on the flow switch until the resistance between pins 1 and 5 drops down to 1 ohm or less.

Reconnect the Coolant ON/OFF cable.

Turn off the power to the 16-050 and unplug the power cord from the back of the system.

Confirm that the power cord is unplugged.

Move the wire on the terminal block form pin two back to pin one.

Replace the electrical cover.

Replace the side covers.

Replace the top cover.

Plug the 16-050 back in and turn on the power switch.

The 16-050 should turn on and off when the 32-095/6 is turned off and on.

Turn off the 32-095/6 and then reconnect the water lines to the X-ray source.

Procedure is complete.

 

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11-065 Ion Gun Control no high voltage

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Over the years I have seen this problem a few times and thought that it would be worth mentioning.

The symptom is that there is no high voltage on the 11-065 ion gun control HV1 board, or the voltage is low.

11-065 Ion Gun Control

11-065 Ion Gun Control

 

 

 

 

 

 

 

On the system, the symptom will  be no or low target current.

If you have this problem the first thing to check is whether or not C5 on the HV1 board is blown out.   It is an electrolytic capacitor and these days most electrolytic have some creases in them which allow the capacitor to expand and release gas and fluid when it fails.

HV 1 board in 11-065

HV 1 board in 11-065

 

 

 

 

 

 

 

The location of C5 on the HV1 board is shown below.

C5 location on the HV1 board in an 11-065

C5 location on the HV1 board in an 11-065

 

 

 

 

 

 

 

For a recent 11-065 repair the symptoms  were no high voltage on the beam and the COND was low. C5  on the HV1 board was obviously blown out so I replaced it.   However I still did not have any high voltage on the beam, and the COND voltage was also low.

The resistors, capacitors, diodes and transorbs on the HV1 board all checked out fine.  It was then that I remembered I have seen this problem once or twice before.   What happened is that when the C5 capacitor failed some of the electrolytic capacitor fluid seeped onto the board.  It was not really noticeable, but there was enough electrolytic capacitor fluid on the board to effectively add a high resistance to the board surface and load down the high voltage supplies.

The schematic for C5 in the filament circuit is shown below.

HV1 board schematic C5

HV1 board schematic C5

 

The solution was to clean the board with a diluted mixture of Alconox detergent and a tooth brush then rinse the board thoroughly in warm water.  Avoid wetting the transformers.  Blow the HV1 board dry with compressed air and then use a heat gun on low to completely dry the board.

After cleaning all of the electrolytic fluid off and drying the board everything worked fine.

Keep this in mind with any electrolytic capacitor failure where the capacitor blows out and  leaks on the board.

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How to test the bias batteries in a 9103 picoammeter

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The 9103 USB picoammeter is often equipped with a +90 V bias option which improves the accuracy of electron and ion current measurements (by reducing the number of low energy secondary electrons that are generated by the beam from leaving the target).

The +90 V bias comprises two 45V batteries in series which are located inside the 9103 chassis.   This blog post will explain how to test and replace the batteries in a 9103 picoammeter.

1. Connect a DVM (digital volt meter) to the 9103 Input BNC connector.  A BNC to double banana cable works well.  Set the DVM to DC volts.

2. In Actuel (the 9103 software), select the input Grounded and bias On.

3. Sample the current.

4. When the bias ON is checked there will be about +90V DC on the input of the 9103.

5 .The input impedance of most DVMs when measuring DC voltage is 10 meg ohms.  The two 45 volt batteries should total 90 to 95V DC.    The bias voltage divided by the input impedance of the DVM will  equal the current.  In this case the voltage of the two 45 volt batteries totaled 94V and the current was 9.414 uA.

9.4 uA in Actuel

9.4 uA in Actuel

 

 

 

 

 

 

 

94 V DC on DVM

94 V DC on DVM

 

 

 

 

 

 

 

6. It is recommended that the bias batteries be tested every 6 months and replaced when the voltage drops below 80 volts.  It is normal for the batteries to wear out over time and with use.  Once the bias voltage drops to less than 50 V the effectiveness of preventing secondary electron emission is greatly reduced, which in turn reduces the accuracy of electron and ion beam current measurements.

The RBD part number for the 45 V battery is BAT-45-213.

Whether you have an RBD 9103 USB picoammeter or an older Keithley with a PHI model 78 bias box, you should test the batteries as part of your preventive maintenance procedure and replace them as needed.

To replace the batteries in a 9103:

Unplug the 9103 USB power and input cables.

Using the Torx wrench that was included with the 9103, remove the screws from the front and rear 9103 chassis covers.

Slide the board out from the front of the 9103.   You will need to rotate the back cover to feed it in. The back cover has a ground wire that is attached to the 9103 board. Also note which groove the 9103 board is in as you will need to put it back in the same groove.

Remove the battery support bracket (white plastic).

Carefully remove the old batteries.

Install the new batteries.You may need to adjust the contacts on the batteries to get them to fit onto the board snaps more easily.

Reattach the battery support bracket.

Carefully slide the back cover and board back into the chassis. Make sure that you put the board back in the same groove that it came out of.  If the front cover does not line up with the chassis then you are not in the correct groove.

Reattach the screws to the front and back covers.  Do not over tighten the screws!

Once you have installed the new batteries, test the voltage. You should have 90 to 95 Volts.

9103 bias batteries

9103 bias batteries