Clean It Up

UK Window Cleaning Forum => Window Cleaning Forum => Topic started by: davids3511 on August 14, 2008, 09:32:09 pm

Title: Should the pump push or pull through DI in van?
Post by: davids3511 on August 14, 2008, 09:32:09 pm
I am not certain how to set my van up. Should the pump be pushing or pulling?
Title: Re: Should the pump push or pull through DI in van?
Post by: Wayne Thomas on August 14, 2008, 09:36:36 pm
pushing through a di
Title: Re: Should the pump push or pull through DI in van?
Post by: Alex Wingrove on August 14, 2008, 10:35:35 pm
pull,

that way the pressure wont build up in the di, and damage it inside, and also any bits of resin that sometime come out will get caught in the strainer before it goes through the pump
Title: Re: Should the pump push or pull through DI in van?
Post by: Nathanael Jones on August 14, 2008, 10:57:04 pm
Push,...

The DI should always be after the pump. They are made to take the pressure,.. mine have labels on the side saying they're rated to 250 PSI if I remember right.

This reduces strain on the pump and helps prevent airlocks.
Title: Re: Should the pump push or pull through DI in van?
Post by: Alex Wingrove on August 14, 2008, 11:03:39 pm
pull!
Title: Re: Should the pump push or pull through DI in van?
Post by: [GQC] Tim on August 14, 2008, 11:08:29 pm
pull!

He just explained why you should have it on push.
Title: Re: Should the pump push or pull through DI in van?
Post by: stevieg on August 14, 2008, 11:12:04 pm
pump sucks water from tank ,pushes through di ,then no chance of any resin getting in the pump.
Title: Re: Should the pump push or pull through DI in van?
Post by: davids3511 on August 14, 2008, 11:28:59 pm
So we have 2 saying pull and 3 saying push!
Title: Re: Should the pump push or pull through DI in van?
Post by: Nathanael Jones on August 14, 2008, 11:32:14 pm
Start a poll David!!

Or as Alex G,.. He always knows the answer!
Title: Re: Should the pump push or pull through DI in van?
Post by: Bazzy1999 on August 14, 2008, 11:32:53 pm
Push...
Title: Re: Should the pump push or pull through DI in van?
Post by: Wayne Thomas on August 15, 2008, 12:17:39 am
pull,

that way the pressure wont build up in the di, and damage it inside, and also any bits of resin that sometime come out will get caught in the strainer before it goes through the pump

Pulling would clog up your strainer quicker than necessary with loose resin seeping from the di and put a strain on your pump. If your strainer gets partially clogged it would also slow down the flow of water after your pump so you would have to turn your dial up on your varistream if you have one fitted which in turn would drain your battery quicker and your battery would need more charging to top up to the same amperage which in turn would shorten the life of your battery.
How do you manage with bits of dirt on the glass which gets in the bristles of your brush whilst you're cleaning the glass?
Title: Re: Should the pump push or pull through DI in van?
Post by: LWC on August 15, 2008, 06:57:33 am
how do you put 2 di vessels in with 2 pumps if the pumps were to push out ?
Title: Re: Should the pump push or pull through DI in van?
Post by: Xline Systems on August 15, 2008, 09:40:16 am
how do you put 2 di vessels in with 2 pumps if the pumps were to push out ?

i am fitting a new system in one of my vans today 1000ltr with 2 pumps and 2 di's
will post some pics later
Title: Re: Should the pump push or pull through DI in van?
Post by: davids3511 on August 15, 2008, 12:02:52 pm
Spoke to Varitech a little while ago. They said that the pump needs to push through the DI. Apparantly the pumps are positive displacement pumps and they don't mind a bit of pressure but do not like suction at all. Sucking through the DI will cause suction and that is not good for the pump.
Title: Re: Should the pump push or pull through DI in van?
Post by: Captain Scarlet on August 15, 2008, 02:07:50 pm
push, anybody thats says otherwise is wrong, Luke
Title: Re: Should the pump push or pull through DI in van?
Post by: sunshine windows on August 15, 2008, 02:22:03 pm
sound like the bloody hokey cokey. push pull push pull shake it all about. lol
Title: Re: Should the pump push or pull through DI in van?
Post by: Alex Wingrove on August 16, 2008, 07:42:53 am
pull,

that way the pressure wont build up in the di, and damage it inside, and also any bits of resin that sometime come out will get caught in the strainer before it goes through the pump

Pulling would clog up your strainer quicker than necessary with loose resin seeping from the di and put a strain on your pump. If your strainer gets partially clogged it would also slow down the flow of water after your pump so you would have to turn your dial up on your varistream if you have one fitted which in turn would drain your battery quicker and your battery would need more charging to top up to the same amperage which in turn would shorten the life of your battery.
How do you manage with bits of dirt on the glass which gets in the bristles of your brush whilst you're cleaning the glass?

i thought that was exactly what the strainer was for, to catch debris before you fire it at the glass
Title: Re: Should the pump push or pull through DI in van?
Post by: [GQC] Tim on August 16, 2008, 09:04:20 am
Spoke to Varitech a little while ago. They said that the pump needs to push through the DI. Apparantly the pumps are positive displacement pumps and they don't mind a bit of pressure but do not like suction at all. Sucking through the DI will cause suction and that is not good for the pump.

Bingo.

Alex Wingrove take notice.  :)
Title: Re: Should the pump push or pull through DI in van?
Post by: Moderator David@stives on August 16, 2008, 10:30:35 am
Push

If you pull you will be liable to air locks esecially if you run out of water occassionally.

It is easy to prime your system if you are pulling water just from the tank with a small hose rather than through a filter system.
Title: Re: Should the pump push or pull through DI in van?
Post by: S.A.J on August 16, 2008, 11:25:15 am
Mine is set by (by Varitech) to push through the DI.
Title: Re: Should the pump push or pull through DI in van?
Post by: Alex Gardiner on August 16, 2008, 11:32:33 am
I would set it up to push through the DI vessel. I do know of several that pull it through though with no problems!
Title: Re: Should the pump push or pull through DI in van?
Post by: michael papworth on August 16, 2008, 12:18:20 pm
Push - without a shadow of doubt.

These pumps are not designed to create a large negative pressure on the inlet; they are designed to create a reasonably large positive pressure on the outlet.

Davids3511 is 100% correct.
Title: Re: Should the pump push or pull through DI in van?
Post by: ftp on August 16, 2008, 07:57:19 pm
I used to pull (ask the missus) but when i changed to push and pressured the di vessel it immediately showed up a leak that i couldn't find pulling so when the push comes to the shove i push.
Title: Re: Should the pump push or pull through DI in van?
Post by: Paul Coleman on August 16, 2008, 08:31:39 pm
This thread sounds like the pullmepushyou from Dr Dolittle trying to give birth.
Title: Re: Should the pump push or pull through DI in van?
Post by: davids3511 on August 17, 2008, 01:35:01 pm
I used to pull (ask the missus) but when i changed to push and pressured the di vessel it immediately showed up a leak that i couldn't find pulling so when the push comes to the shove i push.

That's exactly where I am at right now. My once seemingly watertight setup (pulling) is now sprinkling like a fountain (pushing).
Title: Re: Should the pump push or pull through DI in van?
Post by: stevekennedy on August 17, 2008, 02:06:43 pm
Pumps are not designed to pull but to push. However, as long as you are using a "run dry" pump you will have no problems. Most here are using such pumps. But if it cannot be run dry then you must use it to push.

You might be able to get a siphon action going which will allow you to pull but you will likely get airlocks at times and spluttering.

I have always recommended to push it through the resin.

I thought of setting up a low pressure high flow pump for this purpose. It would then provide a feed for two standard pumps. This way you can run two pumps from one series of filters.

Think I'll start a topic on that  ;)
Title: Re: Should the pump push or pull through DI in van?
Post by: macmac on August 17, 2008, 03:09:56 pm
I have 2 di's & have had them set up both ways, PUSH is the way to go. Although a system will work by pulling, you'll encounter far fewer problems pushing. ;)

Tony