Recent content by Minghan

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    Chemical Composition of nickel alloy

    My sample is a nickel-based alloy The specification is A494/A494M Specification for Castings, Nickel and Nickel Alloy I found this http://209.195.157.233/EDIT/html_historical.cgi?A781/A781M+12a It said that 5.3 Product Analysis—A product analysis may be made by the purchaser from material...
  2. M

    Chemical Composition of nickel alloy

    Is there any regulation about chemical composition about stainless steel which is made from recycling scraps ? Like the percentage of impurity substance such as W , V and etc should not exceed the limit values.
  3. M

    Chemical Composition of nickel alloy

    I ask the foundry to cast nickel alloys and I took a piece metal to do a chemical test. The element composition of the nickel alloy is Ni 70% Cr 12% Fe 1.2% Mo 2.5%...so far they all are in the allowable range. But I found the alloy also contains W 0.004% ! Is this the normal condition ? ? I...
  4. M

    How to determine the power of a rotary lobe pump?

    Want to know how to get the actual power the pump needs. I can measure the flow rate by the flow meter and count the revolutions of the pump. But selecting the proper motor for the pump would be a problem. So I want to know how to determine the power of the rotary lobe pump and generate the...
  5. M

    What is making this sound? (in a Rotary lobe pump)

    Thank you so much! I 'm very grateful for your help !
  6. M

    What is making this sound? (in a Rotary lobe pump)

    Sorry to make you confused. I made this rotary PD pump to suction another high viscosity liquid and I used frequency inverter to change the motor speed. At the full speed, severe noise and vibration happened. Troubleshooting said "The liquid viscosity is too high. The pump is starving. " After...
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    What is making this sound? (in a Rotary lobe pump)

    1. Increasing clearance could minimize cavitation because of adding more slips and more pressure to inlet side ?? 2. And another question making me confused : If the liquid viscosity is too high and rotary PD pump's speed still do not slow down ,then severe noise and vibration will happen...
  8. M

    What is making this sound? (in a Rotary lobe pump)

    1.Could the slip which is caused by higher pressure at the outlet side add pressure to the inlet side and minimize the cavitation ?? 2.And I have read pump troubleshooting and it said that " Noisy operation=> Air or gas in fluid => Dissolved gas or naturally aerated products => Minimize...
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    What is making this sound? (in a Rotary lobe pump)

    "Air entrainment and recirculation will also cause the same rumbling/rattling noise and high vibration as cavitation, as well as the recognizable impeller pitting damage." I understand, thank so much! Pump specs: 120 L/min Type of fluid: Water Temperature: 25°C Pump input shaft speed: 400...
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    What is making this sound? (in a Rotary lobe pump)

    Thank you! And I just wondered if this setting could cause "Aeration" and make bubbles into pipe which make "Cavitation" easier to happen??
  11. M

    What is making this sound? (in a Rotary lobe pump)

    Thank you! And I just wondered if this setting could cause "Aeration" and make bubbles into pipe which make "Cavitation" easier to happen??
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