Vacuum Pump Repair

[Larry Huhn]

I am using an older Nuarc Plate Burner for platinum printing and the vacuum pump will not pull the amount of vacuum that it should. Does anyone have any suggestions on how to improve performance on a rotary vane vacuum pump? I have also sent a message to the pump manufacturer.


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[Erik Larsen]

Many pumps are rebuild able for cheap. The manufacturer might have a kit available with new vanes and gaskets etc. You might check hoses and connections and the gasket that seals against the glass for leaks as well if you haven't already.

[Larry Huhn]

Thanks Eric. I have already emailed the manufacturer to see if a kit is available and I have checked all the connections. I am going to replace the hose in case and see if that helps as well.


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[Gary Beasley]

Another trick with the old vane pumps is to take the connections loose from the intake and with good ventilation away from any fire sources dribble some solvent through the pump while running. This dislodges any accumulated powder from the worn vanes and allows the vanes to seat better.

[Larry Huhn]

Another trick with the old vane pumps is to take the connections loose from the intake and with good ventilation away from any fire sources dribble some solvent through the pump while running. This dislodges any accumulated powder from the worn vanes and allows the vanes to seat better.

Thanks Gary, I will give that a try. I can't get the pump manufacturer to respond about a rebuild kit.


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[Gary Beasley]

Is it a Gast pump? You may need to call them. I recently overhauled mine with a new kit from Gast so hopefully they still have the kits.

[Larry Huhn]

I have emailed and called GAST but they do not respond. But, the good news is that I fixed the pump! Since the pump was getting rapidly worse I decided I had no choice except pulling the pump apart. It turns out that the pump is a diaphragm style pump ( I didn't know) and the problem was debris accumulated under the metal "valves". I disassembled the pump, cleaned everything and reassembled. The pump now works at or close to original specs.


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[nolindan]

I am using an older Nuarc Plate Burner for platinum printing and the vacuum pump will not pull the amount of vacuum that it should.

The chances are the problem isn't the pump but the seal from the blanket to the glass. To check this, turn on the pump with the glass up and plug the vacuum lines and see if the vacuum gauge now reads properly. If the vacuum is still low then I would examine the vacuum hoses for cracks and loose fitings. Only after everything else is eliminated would I suspect a worn pump.

My firm designed a lot of nuArc's equipment - including the nuVac system.

Nicholas Lindan
Darkroom Automation/Cleveland Engineering Design

[Larry Huhn]

The chances are the problem isn't the pump but the seal from the blanket to the glass. To check this, turn on the pump with the glass up and plug the vacuum lines and see if the vacuum gauge now reads properly. If the vacuum is still low then I would examine the vacuum hoses for cracks and loose fitings. Only after everything else is eliminated would I suspect a worn pump.

My firm designed a lot of nuArc's equipment - including the nuVac system.

Nicholas Lindan
Darkroom Automation/Cleveland Engineering Design

Nicholas, the problem turned out to be in the pump. There was crud built up under the metal "flaps" that control the airflow. I cleaned the pump and it works much better. Thanks


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[Drew Wiley]

It takes surprisingly little vacuum to draw down even really big sheets. What is more commonly an issue is air getting under the sheet from somewhere on the
perimeter. You might need some kind of bar or tape system at the edges. But glad you spotted at least one problem already.