How to understand the different curves of balance valve

February 6, 2017 · Posted in Uncategorised 

How to understand the different balance curve to help you better understand the balance valve performance, SUN will show a number of curves in the sample. This article will be through the SUN sample of the more typical types of curves to introduce. (This method also applies to other brand balance valve)

Balancing valve

1. Overflow characteristic curve
The overflow characteristic curve refers to the change of the pressure with the increase of the flow rate when the pilot force is 0 and the load port (No.1 port) passes the oil. Here, we analyze through Figure 1.1 and 1.2.
From these two overflow characteristic Angle Punching machine curves, it is easy to see that the spool opening pressure and the closing pressure are not at one point. (The so-called reset pressure) of this inconsistency (curve hysteresis) is due to the product within the seal caused. The higher the reset pressure percentage, the better the quality of the spool. (Many other brands on the market common “lock live” phenomenon, because the performance is not due.)

sheet metal fabrication View the balance valve overflow characteristic curve can be found in the presence of hysteresis phenomenon, if the overflow characteristics curve “flat”, but under the same pressure flow range corresponding to the wider. This phenomenon is characterized by the acceleration of the actuator action, “instability.” So the use of SUN’s CB series spool, try to avoid excessive use of overflow function. In contrast to the MBEG overflow characteristic curve, we will see that the stability of the hysteresis caused by the problem will be much smaller custom metal fabrication, pressure and flow are almost one to one correspondence. But this corresponds to the pressure increase, so to protect your system MB series balance valve also need to consider its overflow capacity.
It should be said here, only the overflow characteristics curve. Actual use, the balance valve is driven by the pilot, the performance curve is different.

CBEG-LJN overflow characteristic curve

CBEG-LJN overflow characteristic curve

MBEG-LJN overflow characteristic curve

MBEG-LJN overflow characteristic curve

2. Pilot pressure-flow characteristic curve
Figure 2.1 for the balance valve pilot – flow curve. These are the first pressure in the mouth measured under a certain pilot pressure – the main flow of the adjustment curve Drilling Machine for Sieve Plate. Can be analyzed by the figure, the heavier the load itself, it needs less pilot force. All the curves are stable up to go, which indicates that the adjustment process of pressure – flow corresponding to the stability of the problem is not too much. This inside each balance valve, its control curve are not the same, you need to carefully selected.

CBEA-LHN overflow characteristic curve

CBEA-LHN overflow characteristic curve

3. Stroke-flow area change curve
Spool stroke – flow area change curve that is the title picture. This is used to show the spool under different displacement, the flow area of the situation. Through this curve, you can visually see the adjustment of the movement of the valve spool, and adjust the process of smoothness. In general, the spool stroke longer and more gentle, on behalf of the balance valve better control performance.

Change Curves of Stroke - Flow Area of Different Balancing Valves

Change Curves of Stroke – Flow Area of Different Balancing Valves

Combined with these different performance curves, in general, can help you determine the performance of a balance valve is good or bad. However, it is not limited to this in actual use.
“Adjust” balance valve is always a technical live, you need to keep the actual operation, experience.

Comments

Leave a Reply