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Author Archive: Dzyanis

Hydraulic Load Sensing design FAQ

By subscriptions I have received the separate links to “Load-Sensing Systems FAQ” from different suppliers. To read them you need to click the links below, fill the forms and download the PDF files with FAQ:

Of course, it’s free. Next questions are discussed there:

  • How can load sensing be beneficial to a hydraulic system?
  • What is the typical efficiency of a hydraulic system?
  • What are the problems when flow is fixed?
  • How is load sensing technology energy effective?
  • etc.

Flushing of the pipes and tubes

To do pipe flushing correctly we need to provide the special conditions to create turbulent flow. This is required to remove particles from the surface inside spindle tubes. For that we need:

  1.  High velocity of the flushing fluid (not be less than 2 to 3 m/sec. = 106 ft./sec.)
  2.  High temperature of the flushing fluid (a minimum temperature should be 140°F = 60°C)
  3.  Low viscosity of the flushing fluid (in the 10 to 15 cSt range at 104°F = 40°C)
  4.  The pressure of the flushing fluid should be held to a minimum 3 to 5 bar (22 to 73 psi), measured downstream from the flushing circuit, before the return line filter and sampling port
  5.  The flushing time to be 30 min.

Next good references about flushing I found in the internet and want to share:

Pilot Operated Check Valves or Counterbalance Valves?

Summary:

  • When use Pilot Operated Check valves?
  • When use Counterbalance valves?
  • Design advises for topic valves.

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First of all, Pilot Operated check valves are NOT a cheap solution of Counterbalance valves.

Yes, both of them have next the same benefits:

  • Prevent a load from dropping in case of hose or tube failure.
  • Prevent a load from drifting caused by directional control valve spool leakage.
  • Leak-free load holding.

But each of them has the specific applications.

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