stephen.b1

  • Posts: 259
why do you need a varistreem
« on: March 25, 2006, 12:34:18 pm »
if you are having to control the flow of water with a vs then the pump you have is too big the pump is designed to switch off when it gets to the max presure so why not let it do its job
using a vs dose not prolong the life of a pump the pump just takes longer to turn off and rest

Roy Harding

  • Posts: 1964
Re: why do you need a varistreem
« Reply #1 on: March 25, 2006, 01:49:33 pm »
Stephen

The problem with leting the pump switch off with its preasue switch, can cause the pump to cycle and this burns out the preasure switch.

Also if you are pumping over 100mtrs with two men using 100mtrs each a higher preasure pump is needed.

But I see your point.

Roy

stephen.b1

  • Posts: 259
Re: why do you need a varistreem
« Reply #2 on: March 25, 2006, 01:56:01 pm »
sorry what do you mean by cycle

Roy Harding

  • Posts: 1964
Re: why do you need a varistreem
« Reply #3 on: March 25, 2006, 02:03:40 pm »
Hi Stephen

When  you stop the flow on the hose by say a flow control tap, the pump will keep going till the preasure switch stops it. This is fine for a while but then the pump with switch on and of very quick as is stuttering and the pump will not run, this is called cycling.

Roy

stephen.b1

  • Posts: 259
Re: why do you need a varistreem
« Reply #4 on: March 25, 2006, 02:13:59 pm »
this is my point there is solutions to this and is not a vs and is a cheaper and better solution have to go out now will be back latter

Re: why do you need a varistreem
« Reply #5 on: March 25, 2006, 03:42:27 pm »
Cycling/stuttering:

It is likely to happen when you restrict the flow by using something like an inline flow control. Without a Varistream the piump will always work at full rate. This leads to backpressure inline to where your flow control is. The pressure switch on the pump is fooled into thinking you have turned your flow off and stops the pump. The pressure drops quickly again as your water flows out releiving the backpressure. The pump switches itself on again. Backpressure builds up again rapidly and the whole "cycle" repeats itself. This can and does happen every second or so. This is what does the damage.

The Varistream prevents this by setting the pump to the speed that is needed to maintain exactly the flow you require.. You can still use an on/off valve inline and the varistream will stop the pump when you close it. When you open it again you get exactly the flow you had set. Also the Varistream will compensate for both length of hose you are using and the height at which you are working. You always get the same flow rate at the brush with the pump only having to work at whatever speed is required.

Andrew

Tim Morton

  • Posts: 201
Re: why do you need a varistreem
« Reply #6 on: March 25, 2006, 05:13:34 pm »
using a vs dose not prolong the life of a pump the pump just takes longer to turn off and rest

Actually a Varistream does prolong the life of the pump as you no longer need the pressure switch on the pump, this is what burns out due to the cycling as described so well by Andrew McCann above. Using a varistream means you bypass this pressure switch thereby prolonging its life.
Tim
Measure with a micrometer, mark with chalk, cut with an axe!!
Craigavon, N.Ireland

Alex Gardiner

  • Posts: 7740
Re: why do you need a varistreem
« Reply #7 on: March 25, 2006, 08:16:11 pm »
We have been using Flojet pumps now for 5 years. We use between 60 and 100 metres of microbore which gets the flow rate just about right. We have flow control valves on our poles to switch them on and off and also to provide an amount of flow control.  Our pumps must switch on and off thousands of times a week, we have NEVER had a pressure switch burn on any of our pumps. We have one simply wear out after 3 1/2 years use but the pressure switch was still fine.

Obviously some people will get a duff pressure switch that does wear out or are perhaps using the cheaper brand of pumps which some have found to not last as long.


With the above set up we have never found the slightest need for a varistream, and when aproached to stock them on our site we have declined due to a belief that with our set-ups they would be surplus to requirements.


This is just our opinion based on 5 years WFP use.

ALex

Filllllll

  • Posts: 82
Re: why do you need a varistreem
« Reply #8 on: March 25, 2006, 08:23:11 pm »
If you mess about controlling flow with your manual control (i.e. half open or a third open) not put strain on the pressure switch & soon burn it out?

This was my experiance with sureflo pumps & hence got a varistream which works really well.

Are flojet therefore  better than sureflo?

gaza

  • Posts: 1642
Re: why do you need a varistreem
« Reply #9 on: March 25, 2006, 09:14:17 pm »
MUST DISSAGREE WITH MOST OF U.
4 YRS SAME PUMP AND STILL GOING STRONG USE A MANUAL CONTROL SYSTEM
IN LINE ON PIPE FITTED BY TUCKER POLES

  VARISTREAM ONLY IS USEFULL FOR A STEADY STREAM OF WATER PRE SET,WHICH i WILL BE FITTING LATER TO MY SYSTEMS.

 GAZA
IM AT THAT AGE MY BACK GOES OUT MORE THAN I DO

stephen.b1

  • Posts: 259
Re: why do you need a varistreem
« Reply #10 on: March 25, 2006, 11:09:02 pm »
i have been working with pumps from 100watts to 3.5 hp for the last 23 years  in hobby and part time bussines of koi  and that still dont make me an expert  ;D
varistreams arnt new we were using similar controlers on pumps of 1.5 hp to reduce flow rates in the winter and full rates for summer
varistreams are fine for controling constant flow rates but wfp dose not use constant flow rates so these are not the answer.

gaza

  • Posts: 1642
Re: why do you need a varistreem
« Reply #11 on: March 26, 2006, 12:34:36 am »
varistreams just another gizmo hozelock tap controller with a hozelock end stop so the water stops coming out of the pipe when unplugged

set the flow control in the van leave it like it all day or for ever more once iits set or marked  for 1st clean flow, second clean rate,for every clean flow rate you can plug in your hose and work all day if you like at the rate youve set

 gaza
IM AT THAT AGE MY BACK GOES OUT MORE THAN I DO

pjulk

Re: why do you need a varistreem
« Reply #12 on: March 26, 2006, 12:47:58 am »
I have a varistream MK2.
And have been using it for about 9 months.

I am now removing it and fitting a bypass instead.
Im not that struck on the varistream and if i want a high flow then it starts cutting out.
I know you can adjust the pressure which i have done many time by turning the blue dial and it still does it.
Its great if you want really low pressure as its constant then.

But for me its comming off and have a bypass instead.
I have a flow valve fitted to the bottom of my pole and also one on my trolley so there is no need for it really.

I don't think many people have problems with the pressure switch burning out.
As until they came out last year no one was using them and they didn't get many problems.

Paul

MartinB

  • Posts: 88
Re: why do you need a varistreem
« Reply #13 on: March 30, 2006, 05:39:20 pm »
Paul

Sorry to hear your not too happy with the Varistream.

I must say though in response to other postings on this thread, we initially designed and built the Varistream BECAUSE of the large number of pressure switch failures on all pumps on this type of application, due mainly to people fitting DIY flow control valves.

Judging by its popularity and the amount we have sold, perhaps this decision was correct.

However, it is not simply a way to reduce the water flow. It is also designed to Auto Compensate to ensure the same flow is achieved at whatever height the brush is working at.

Martin Burrows
Williamson Pumps Ltd

sair

  • Posts: 682
Re: why do you need a varistreem
« Reply #14 on: March 30, 2006, 05:51:51 pm »
they didnt come out last year paul i have had our eco flow going into 2nd year ionics systems have been using similar control for possibly nearly 5 years i feel they work better and give a more precise control on the water
Essentially Pure Ltd

pjulk

Re: why do you need a varistreem
« Reply #15 on: March 30, 2006, 08:31:00 pm »
Hello martin.

The varistream is a good piece of equipment and i know a lot of them like it.
Maybe it would be better with a 100psi pump as i use 60 psi.
Like i said i have been using mine for 7 months and have now changed back with a bypass and using gardiners flow control valve on my pole.

For me this is far easier.

But i am going to keep the varistream because if i get another system which maybe on the cards shortly.
I will make sure it has a 100psi pump and will probably work a lot better for me then.

Paul