Home/ Questions/Q 4510
In Process

Answer it Forward Challenge
  • 0
Asked: 2023-02-28T14:07:00+00:00 In:

Why diffusion pump doesn’t work properly?

  • 0
There is a brazing vacuum furnace that we are currently using. We are experiencing various problems with it. We think that it is probably due to diffusion pump.
All gaskets were renewed, difussion oil was replaced with new one.
Control tests were performed with a helium detector.
Internal water cooling leak test done.
Air and Helium Tests were performed on water places.
Although we did all these, when we opened the diffusion valve, it did not work actively.
And there is a little oil on the side of the oven, what is the reason?
Our pumps are less than 1 year old and new.
There are 2 pieces of (150 capacity) 1200 Roots BOOSTER pumps.
This is an urgent issue thats why we would like your contribution and assistance regarding solving the problem as soon as possible.
diffusion pump
Share

    You must login to add an answer.

    1 Answer

    1. Official Account of VacuumFurnaces.com
      This answer was edited.

      If your diffusion pump is not working properly, several potential issues could be affecting its performance. Here’s a list of common causes and diagnostic steps:

      1. Insufficient Heating

      • Issue: The diffusion pump relies on heating the oil to create vapor jets, which then carry away gases. If the heater is malfunctioning or not reaching the proper temperature, the oil won’t vaporize correctly.

      2. Cooling System Problems

      • Issue: Diffusion pumps require adequate cooling to condense oil vapors back to liquid form. If cooling is insufficient or blocked, the pump may overheat, leading to inefficient operation or even backstreaming of oil.

      3. Contaminated or Incorrect Diffusion Pump Oil

      • Issue: If the oil is degraded, contaminated, or the wrong type, it can cause backstreaming, poor performance, or even pump failure.

      4. Improper Venting or Isolation

      • Issue: If the pump is not properly isolated from the system or not vented correctly, it could allow air to enter, reducing the vacuum level.

      5. Faulty Diffusion Pump Valve or Interlock System

      • Issue: Sometimes, a malfunctioning valve or an interlock can prevent the diffusion pump from operating correctly. This can result in the pump not engaging properly or being stuck at a higher pressure.

      6. Leaks in the Vacuum System

      • Issue: Leaks in the system can prevent the diffusion pump from achieving low pressures. Even small leaks can significantly impact performance.

      7. Backstreaming of Oil

      • Issue: Backstreaming occurs when oil vapor moves in the opposite direction and can reach the vacuum chamber, contaminating the system and reducing pump effectiveness.

      8. Obstructions or Contamination in Pump Lines

      • Issue: Dirt, residues, or contaminants in the pump’s internal channels or outlet can reduce the efficiency of the vapor jet and restrict gas flow.

      9. Improper System Pressure Staging

      • Issue: Diffusion pumps are designed to work only within specific pressure ranges. Starting the diffusion pump while the chamber is at too high a pressure can impair its function.

      By working through these potential causes you can systematically eliminate common diffusion pump issues and restore efficient operation in your vacuum system.

      • 0