Water Control Solutions

real-time data and IR_LP_TopImg.png
Lobby_How_can_two_pilots_operate_on_one_hydraulic_control_valve_2

How can two pilots operate on one hydraulic control valve?

Micha Baer
By
Micha Baer 17 Jul 2019

Recently, one of our customers asked how is it possible for two pilots to operate on the same hydraulic control valve without interfering with each other's operation. In this short blog, we will describe how hydraulic control valves with two pilots operate.

Question

How can a single hydraulic control valve, equipped with two pilots, each with a totally different designated function, operate fulfilling the two functions, without the two pilots interfering with each other's operation?

Blog_images_How_can_two_pilots_operate_on_one_hydraulic_control_valve_v34

Note

The question and the following response were directed at BERMAD's Flow Control & Pressure Reducing Valves, such as models IR-472-U, IR-172-d and IR-972-V, but can also be applied to any of BERMAD's control valves which are equipped with two pilots or more.

Answer

BERMAD's Flow Control & Pressure Reducing Valves are used in systems with high pressure on one hand, and a wide range of demand which can affect the supply system on the other hand. The Flow Control & Pressure Reducing Valves are installed in key points, such as consumer connection/offtake and function as follows:

  • - During periods where the demand is higher than the supply, the valves are required to limit the flow through them, to ensure an even water supply to all the consumers and to protect the supply system from significant drop in pressure

  • - During periods where the demand is lower than the design flow, the pressure will rise, even higher than the pressure rating of the pipes and accessories, so the valves are required to reduce the pressure

Another example where Flow Control & Pressure Reducing Valves are commonly used are gravity supply systems for multiple users located at various elevations. In these systems, the users located at lower elevations may consume more water, at the expense of the users located at higher elevations.

BERMAD's Flow Control & Pressure Reducing Valves, such as models IR-472-U, IR-172-d and IR-972-V, are equipped with two different pilots, where one pilot is performing the Flow Limiting function and the second pilot is performing the Pressure Reducing function.

The following table and illustration are used as an example to demonstrate how the pilots, separately and together, control an IR-472-U Flow Control & Pressure Reducing Valve to open or throttle as required by the conditions in the system and the set points.

Possible scenario 1 2 3
Demand High Low Low
Downstream Pressure Low High Low
Flow limiting Pilot (2W) Closed Open Open
Pressure Reducing Pilot (2W) Open Closed Open
Main Valve *Closing *Closing Opening
* Closing – valves modulate to close until reaching the required set point
  • - The valve will open only when both pilots are open
  • - The valve will close when any one of the pilots is closed
  • - An open pilot is "giving" the control of the valve to the second pilot
  •  
  • IR-472-U  Control Diagram

  • Blog_images_How_can_two_pilots_operate_on_one_hydraulic_control_valve_v35-2

New call-to-action

Topics: Flow control, Irrigation, Pressure Reducing Valve

Micha Baer

Written by Micha Baer

BERMAD Application Engineer with the Waterworks sector in Asia, Australia, and New Zealand. Giving technical support and sharing knowledge with Bermad's personnel in the subsidiaries and with customers.

How can two pilots operate on one hydraulic control valve? _CTA2

Recent Posts

Never miss a story