[Mike55]

Hi Guys, hopefully someone can help me out here...

My flow controller on my van has been playing up so I have swapped it for the one from my pure freedom trolley (flow master analogue controller).

However when I turn the controller on the pump fires out water, even on the lowest setting.

Is there anyway to reduce the flow rate as it did not get this problem when the controller was used on my trolley?

Incidentally the the pump is a sureflow the same as the trolley.

Any help appreciated.

[Tom White]

Have you recalibrated it?

[Mike55]

I have recalibrated the pressure switch screw (small hex screw at the base) which did set the pressure cut off correctly when closing the water flow with a flow control valve.  It shuts off quickly, however it did not adjust the flow rate when in use which is too high.

[Peter Fogwill]

The screw doesn't adjust the flow rate it only determines the pressure build up in the pipes when the water is dead ended.

[Ian Sheppard]

Hi Guys, hopefully someone can help me out here...

My flow controller on my van has been playing up so I have swapped it for the one from my pure freedom trolley (flow master analogue controller).

However when I turn the controller on the pump fires out water, even on the lowest setting.

Is there anyway to reduce the flow rate as it did not get this problem when the controller was used on my trolley?

Incidentally the the pump is a sureflow the same as the trolley.

Any help appreciated.

Hi Mike

I have a few questions that may help us get to the bottom of the issues. 1st it what may was the van controller playing up? 2. are both controls analogues?
3. What calibration settings do you run on?
4. Is there a fuse fitted in line and what rating is it?

Thank you to Tosh and Peter for coming in on this. Calibration of the control may help. Calibration of the control tells the control what the base pressure in the system is. The Calibration setting on the control effects how fast the control drops the pump into DE when water flow is stopped. The Higher the setting the slower the control response to stopped flow.

Ideally the control would always stop the pump (DE) rather than using the pump pressure switch to do it. 

[Steven Biggs]

Does messing with the small screw on the pumps pressure switch still make a difference when you are using a controller . I thought when using a controller you bypassed the pressure switch so turning the screw makes no difference . Unless I'm wrong .

[Ian Sheppard]

As Peters comment adjusting the pump pressure switch does not have an impact on flow only the point at which the pump will stop due to high pressure. Setting the pressure switch to low may mean the pressure switch activate at very low pressure.

With some controllers yes you will need to disconnect the pressure switch.
But with the controller in question here, it is designed to operate with the pump pressure switch in line. With the controller calibrated the control should stop the pump and display DE. We would expect the control to DE the pump before the pressure switch is activated by high system pressure.

We engineer the control to operate with the pump pressure switch in line, as it provides an additional fail safe on the system in the event of something unexpected happing.

Adjusting the calibration dictates the response time of the control in stopping the pump when flow has stopped. The higher the calibration figure the slower the control response time.

In effect calibrating the control to the pump and system allows the control to know the base operating pressure of the system. When flow is shut off the pump tries to push against the restriction increasing system pressure, the control sees this change and stops the pump. As flow is restored the control restarts the pump.

[Steven Biggs]

When using hot water would it be normal to alter the calibration . I've filled up with hot the last 2 days and had to lower the cal from e down to b . Or would it be more to do with the cold weather . Cheers barry .

[Ian Sheppard]

Hi Steven

This is the effect of water viscosity. Warm water will flow more easily than cold. Bit like a slush puppy V a cup of hot tea. The hot liquid has a much lower viscosity and flows more easily.

Also the hose wall expansion rate changes the warm water make the hose much more flexible. These changes to the water and hose expansion rates means the system pressure also changes. So yes I would expect to see Calibration settings alter dependent on water temperature.  The warmer the water the lower the calibration would likely be. The pressure can build quicker so the control needs to be more sensitive and more responsive when Dead ending the pump.

[Steven Biggs]

Thanks for that reply Ian . Explained it for me . Just been out to the van and put some hot in the tank . Lowered the cal down to b and it's working perfect . Cheers barry