No Pressure.

[Math]

Hi Everyone,

Would really appreciate your help. I have two hose reels, two shurflo pumps , two controllers and two leisure battery's with Voltage at 12.8 sometimes es drops to about 12.3.

I cannot get any real pressure from the pumps. I have had a P5 and a DE error message.

I've tried to calibrate pumps as well but nothing is working

Any ideas thanks

 

[dazmond]

P5 and DE aren't error messages on the controllers mate.They stand for Pressure Switch and Dead End....

DE is normal and in operation this should come up when you turn your water off and stop the pump

P5 means Pressure Switch activated usually caused by too much pressure in your system and usually means you need to drop down the calibration and flow a little.It can also be caused by a blockage in your system(check pre filters and connectors)or a loose wire or air in the system

You normally have to turn the pumps up a bit more on colder days if you run a cold water system because the hoses are stiffer thus restricting flow

 

[spruce]

Hi Everyone,

Would really appreciate your help. I have two hose reels, two shurflo pumps , two controllers and two leisure battery's with Voltage at 12.8 sometimes es drops to about 12.3.

I cannot get any real pressure from the pumps. I have had a P5 and a DE error message.

I've tried to calibrate pumps as well but nothing is working

Any ideas thanks

We presume, by pressure, you actually mean rate of flow.

I noticed today how my flow rate at the brush head is much less than it has been of late. I didn't actually check the water temperature in the tank today, but as the van has been standing for the past week, it was probably 8 degrees, which was the internal battery temperature this morning.
I increased the flow on my controller from 3 to 4, but it still seemed low.

There are numerous threads on flow rate on the forum. Our hose expands a little under pressure when the water is warm. As the water gets colder, the hose becomes less flexible - more rigid. This impacts on water flow rate.

There was a flow rate comparison on a website page that, unfortunately doesn't exist now. They were discussing flow rate through straight steel pipe.
The flow rate difference between 6mm and 8mm bore steel pipe is considerable. At 4 bar, (56psi), the flow through 6mm pipe (microbore), is 0.022 litres per second (1.32 litres per minute). The 8mm pipe (minibore), is 0.056 litres per sec (3.36 litres per minute), at the same pressure. A 6mm tube (in our case microbore), will only allow fractionally less than 1/2 the volume of water at 4 bar. Our hose coiled up around a hose reel will probably reduce those figures a bit more.

Hot water will have a higher (or is it lower) viscosity (less dense) so will flow better through a smaller diamt hose. So most hot water users happily use microbore hose. The colder water gets, the lower the flow rate. Freezing water is a solid and won't flow at all.

Water flowing through a hose can either be Laminar flow or Turbulent flow. Once fluid in a tube reaches a certain speed, it becomes turbulent. Once it becomes turbulent, it requires 4 times the amount of pressure to double the flow rate. Fluid through hose coiled on hose reels won't be laminar in flow but turbulent. If you look at a running stream, the water is the centre is smooth running or laminar. But if you look at the water at the edge, it swirls around, turning back on itself. They are called Eddies. That's turbulence flow.

Of course, you could have a restriction somewhere along the pipe. Best to uncoil the hose completely off your hose reel and check for any twisted hose. We had a problem once with Hozelok stop connectors, and when we used EZ snap/Schrader hose to pole hose connectors, we also had a problem once.