[Matt Gibson]

What is this in the red circle? The guy says its a flow switch, but ive never come across this before. What does it do? and why doesnt this pump have an unloader on it?

[BDCS]

That would normally be the unloader but the switch would be a pressure switch. They are normally fitted to electric pressure washers so when the trigger is released and the pressure builds, the switch stops the motor via the relay. They can also be used to drop the motor revs during unloading to save fuel.

[Matt Gibson]

So why is it there on this engine? What would be the point of it being put on there?

And how does it unload? im assuming that this setup DOESNT unload?

[BDCS]

I will unload - is the switch not on the top of the unloader ? It will have a relief if not an unloader but it would kill the relief very quickly. I would say that if the revs don't knock back to idle then I recon that unloader has been nicked fron an electric m/c. Any chance of a better photo ? What make is it ?

[Matt Gibson]

Its a hawk pump, Lombardini 3 cyl engine. Dont think the revs can be knocked back. its similiar to my existing engine. Looks like there is no unloader on it. the pressure switch is just screwed into an elbow which comes out of the pump head. other side of pump head goes to hose reel. Not really sure what the pressure switch does if there is no unloader..

[BDCS]

There will be an unloader or it will just stall the engine or go bang. Was it a jetter ? I don't have an unloader on mine but you cannot use a dead stop gun - you have to use a dump gun so the flow never stops. If this is the case then there will be a bursting disc fitted to the pump

[Matt Gibson]

I think it was originally a jetter but its been rebuilt as a washer. i had a look and couldnt see an unloader anywhere. The guy uses a normal gun with it.

im thinking of buying is all so im just trying to work out what it is. ill probably just stick and unloader on it if i buy it. althiugh now i come to think of it, it had a pressure control nob (like an unloade twist control spring) sticking out the side of the trailer.

[BDCS]

That is a panel mounted unloader  from there it will go to the gun and a return to tank

[Rob_Mac]

Matt

Ive just sold Simon @ Pristine a drain jetter, had a very strange unloader set up, not like anything i had seen before, manual unloader, very weird.

Got the service guys to stick an unloader on it and good as gold

Rob

[Matt Gibson]

So is the panel unloader the same as a normal unloader, just moved to a different position?

Like a hose from the pump head all the way to the unloader then from there to the gun? Like a remote unloader so to speak?

So if its got an unloader what does the pressure switch do? Is it in case of over pressure? Just never had a pressure switch or even heard of one.

Ignorance is bliss sometimes 

[Matt Gibson]

Matt

Ive just sold Simon @ Pristine a drain jetter, had a very strange unloader set up, not like anything i had seen before, manual unloader, very weird.

Got the service guys to stick an unloader on it and good as gold

Rob

Rob,

Im thinking if i buy it ill eventually just re-do it the same way as my other machine is. keeps thing simple.

the reason im looking at this is because my machine ive got at the moment has given me some good service and the one for sale is the same engine but its already on a trailer so means i can put it straight to work and not have to build up a trailer bit by bit. plus its only down the rd from my place. hopefully he will like negotiating  

[BDCS]

The pressure switch may be set higher than the unloader and would cut the engine should over pressure occur. Without seeing it I'm only guessing but you could trace the wire back to ?

I'm about to start building a trailer - just as I want it

[Matt Gibson]

Ill have another look next time im there. are these pressure switches pre set?

I was planning on building one custom, but finding a decent machine locally is hard. plus ive got a hotbox and a genny in the van. this new machine also has a burner on the trailer. small water tank though as per all jetters. maybe in the future ill put it onto a flatbed trailer with an ibc.

[BDCS]

My jetter has a  400 ltr tank - plenty for about 8 mins flat out  I've bought a 650 ltr tank for the new trailer which will have the washer and the boiler plus the two hose reels. I've got a selection of old jetters in the yard - can't make my mind up between manual or electric rewind reel 

[Simon@Pristine Pathways]

Robs right  new unloader... good as gold!

Spoke to service lad today sorted nozzel sizes, the splitter getting sorted tommorow.

Can I join the big boys with big washers club now? Or just you and lee blastaway in that?

 

[BDCS]

I rarely ever use the Harben for washing, the washer I use is only 21 ltr/min as I don't get much call for big jobs.

[Matt Gibson]

can't make my mind up between manual or electric rewind reel 

Hard life with decisions like that 

Why do those drain jetting trailer have such small water tanks? The one on the trailer im looking at litterally has 50L tank. The diesel tank is bigger!!

[Blast Away]

Is it not like a low water flow switch? Kills the engine when no water left in tank.

[chris scott]

Switch the burner off if there is no water going to it?

[Matt Gibson]

Switch the burner off if there is no water going to it?

Spot on. Apparently its a pressure switch for the boiler. When the boilers switched on and the triggers pulled the boiler turns on. Let goof the trigger the boiler turns off.

I thought this was what the flow switch on the boiler did??

Also, its got an unloader like normal, but where the hose goes from unloader to boiler, there is another unloader next to the boiler flow switch??