Debugging method of reverse osmosis pressure switch for water treatment

The high/low pressure protection of water treatment reverse osmosis equipment is to prevent the RO high-pressure pump from idling or working at high/low pressures beyond the limit.    

High-voltage switch is used for high-voltage protection. With the increase of equipment use time, the membrane will be fouled, the natural membrane inlet pressure will increase, when the pressure increases to a certain extent, in order to protect the equipment and pipelines from damage, it is necessary to have a high-voltage switch for protection, and when the pressure increases to the preset value of the pressure switch, the equipment will be forced to stop.

Low pressure switch, when the pressure in the inlet pipe is low, the reverse osmosis membrane can not work normally, and will always discharge wastewater, so when the inlet pressure does not meet the working requirements, the circuit will be cut off and the machine will stop working. When the pressure in the inlet pipe reaches the working requirements, it will start working again.

How to debug the reverse osmosis pressure switch for water treatment?

The low-voltage switch has two adjustable screws, one is to adjust the reference pressure, generally 0-6bar, and the other is to adjust the differential pressure, generally 0-2bar, which can be adjusted with a screwdriver.

There are two possibilities for the common low-pressure switch to always jump, one is that the raw water pressure fluctuates greatly, and the other is that the reference pressure is near the raw water pressure value and the differential pressure is small.

Raw water pressure fluctuation solution Exhaust the pretreatment equipment and increase the opening of the outlet valve of the raw water pump, so that the pressure of the raw water is relatively large, and it is not easy to jump.

 Solution to small differential pressure: 

1、Observe the pressure of the equipment during normal operation, and adjust the reference pressure to a slightly lower point, such as the pretreatment permeate pressure is 2.5bar, then the reference pressure can be adjusted to 2bar;

2、Set the pressure value of low pressure jump, for example, when the raw water pressure is lower than 1.5bar, the pressure switch starts to jump, then adjust the differential pressure to 0.5bar;

3、Although it has been adjusted, the accuracy of the adjustment is also different, so, Adjust according to the actual pressure situation until it reaches your own requirements, such as suction at 2bar pressure, and jump open at 1.5bar pressure (at this time, the pressure can be adjusted by adjusting the high-pressure pump valve or the outlet valve of the raw water pump).

4、 If you want to make the pressure return range larger, you can also adjust the return pressure to 0.8-1.0bar, so that when the pressure reaches 2bar, it will be sucked up, and when the pressure is lower than 1bar, it will jump away.