[JTHRC]

Anybody know how to reduce flow on shurflo pump without using varistream? can u do it with and allen key??

Thanks

[Richard Neal]

you need a return to your tank which you can adjust using a tap / valve

[JTHRC]

sorry i dont understand??

[Richard Neal]

On my van i have my shureflo with a on off switch, the hose between the pump and hose reel has a tee piece fitted with a hose going back into the top of my tank, attached to this is a tap, if i have this closed the water pressure to my hosereel is very high, if i open the tap to the tank to allow some water to return into the tank the pressure drops out of the hosereeel. It does work very well the only drawback is that the pump is running flat out all the time!

Hope this explains it  

[JTHRC]

ok i understand. thanks....i just thought their might be a way of reducing the flow without doing that and also using a varistream.

i might give this a go
thanks

[Tom White]

I think you'd just be better off using a varistream; 'cos you may do the same as me; spend ages fannying about with taps and return valves, fail to get it working, and just end up using a flow controller anyway.

I personally recommend you cut out the expense and messing about, and just get a flow controller.

[Ian Sheppard]

One of the benefits of a controller is that it means the pump is not working flat out all the time, so should help protect the pump, if the pump is running slower this does also reduce the draw on the battery so giving you longer per charge. The controller also gives you dead end protection rather than relying on the pump pressure switch if pressure builds to high.

That said it is all about what works best for you.

[John Walker]

I've measured the voltage that my varistream is feeding to my Shurflo at my required flow rate and it is 6 volts.

I'm wondering a simple answer would be to just use a suitable 6v battery instread of a 12 volt one..

Any sparks got any comment on this idea..... - I'm sure it can't be that simple or we would all be doing it.

[Spruce]

I've measured the voltage that my varistream is feeding to my Shurflo at my required flow rate and it is 6 volts.

I'm wondering a simple answer would be to just use a suitable 6v battery instread of a 12 volt one..

Any sparks got any comment on this idea..... - I'm sure it can't be that simple or we would all be doing it.

An electronic speed controller is more than an inline resistor that reduces the voltage and hence the motor's speed. The electonics are a complicated design that maintain the motor's torque by altering the current using pulse width modulation.

When I worked for Bosch Power Tools many years back, vast sums of money were spent designing the early electronic 12v battery screwdrivers and drills to enable RPM to be dropped but not motor torque.
If they could have done it with resistors it would have saved them a packet. 

Spruce

[John Walker]

I've measured the voltage that my varistream is feeding to my Shurflo at my required flow rate and it is 6 volts.

I'm wondering a simple answer would be to just use a suitable 6v battery instread of a 12 volt one..

Any sparks got any comment on this idea..... - I'm sure it can't be that simple or we would all be doing it.

An electronic speed controller is more than an inline resistor that reduces the voltage and hence the motor's speed. The electonics are a complicated design that maintain the motor's torque by altering the current using pulse width modulation.

When I worked for Bosch Power Tools many years back, vast sums of money were spent designing the early electronic 12v battery screwdrivers and drills to enable RPM to be dropped but not motor torque.
If they could have done it with resistors it would have saved them a packet. 

Spruce

Hi Spruce

Fully understand what you are saying - however one of my trolleys has a very heavy duty 3 ohm resistor in series and works a treat for domestic work where the flow rate etc remains constant.  Been using it for around 8 years now.  7 volts showing across the pump motor under load and results in 2 litres per minute flow as against just over 4 litres per minute without the resistor.  The resistor runs quite warm but it's an old fashioned item in a big ceramic moulding.

My thinking with using a 6 volt battery means full torque and no resistor in play - I think..... 

[Spruce]

I've measured the voltage that my varistream is feeding to my Shurflo at my required flow rate and it is 6 volts.

I'm wondering a simple answer would be to just use a suitable 6v battery instread of a 12 volt one..

Any sparks got any comment on this idea..... - I'm sure it can't be that simple or we would all be doing it.

An electronic speed controller is more than an inline resistor that reduces the voltage and hence the motor's speed. The electonics are a complicated design that maintain the motor's torque by altering the current using pulse width modulation.

When I worked for Bosch Power Tools many years back, vast sums of money were spent designing the early electronic 12v battery screwdrivers and drills to enable RPM to be dropped but not motor torque.
If they could have done it with resistors it would have saved them a packet. 

Spruce

Hi Spruce

Fully understand what you are saying - however one of my trolleys has a very heavy duty 3 ohm resistor in series and works a treat for domestic work where the flow rate etc remains constant.  Been using it for around 8 years now.  7 volts showing across the pump motor under load and results in 2 litres per minute flow as against just over 4 litres per minute without the resistor.  The resistor runs quite warm but it's an old fashioned item in a big ceramic moulding.

My thinking with using a 6 volt battery means full torque and no resistor in play - I think..... 

Hi John.

Guess there is no problem in experimenting with a really heavy duty resistor as that pump will draw 6 to 7 amps on full throttle. If its a 'controlled' experiment then you can always bale out of it if something smells as though its overheating.

Spruce