Problems with outlet pressure control of gear pumps.
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Problems with outlet pressure control of gear pumps. When the pump outlet pressure remains at a constant value and does not change frequently, an overflow valve is installed to allow the excess pressure to flow back when it rises too high. But now, in a certain operating condition, the pressure at the pump’s outlet often needs to change – it might be 2 MPA at one time, and then 10 MPA in the afternoon. In such cases, wouldn’t an overflow valve be less useful? When the relief valve is set to 10 MPa, it becomes ineffective under low-pressure conditions. Surely we can’t manually adjust the relief valve pressure every time the operating conditions change, right? Are there any products that can remotely and automatically adjust this overflow pressure? I wonder if a electro-hydraulic proportional valve in combination with a pump outlet pressure transmitter can meet the above requirements Another question is: as a rule, should an accumulator be installed first at the outlet of a gear pump, or should a relief valve be installed first? I am usually exposed to centrifugal pumps and know little about hydraulic pumps.
Positive displacement pumps are different from centrifugal pumps; the pressure in positive displacement pumps is determined by the back pressure
Yes! What’s the best approach for dealing with such frequently changing back pressure?
Simply put, install two relief valves in parallel: one at 2 MPa and another at 10 MPa. Install a DCS-controlled automatic valve in front of the 2 MPa relief valve; the automatic valve opens when the outlet pressure reaches 2 MPa, and it closes when a pressure of 10 MPa is required
I didn’t express myself clearly; since it’s a test, the actual operating conditions involve conducting tests at any possible value within the range of 2–10 MPa. So it’s impossible to equip a bunch of relief valves. Is the electro-hydraulic proportional valve I mentioned below suitable for such operating conditions?
The pressure of a positive-displacement pump is determined by the back pressure
The pressure of a positive-displacement pump is determined by the back pressure
Yes, then for operating conditions where this back pressure changes frequently, how should the relief valve be configured?