Flow controller valve

[Waffty]

I wonder if any can help, I'm using a Arduino to control the amount of sparge water, I put into my mash tun. The idea is that I use a flow meter and a 12v solenoid in series between my HLT and Mash tun. I enter the amount of sparge water I require, open the valve, the Arduino counts down the litres require (via the flow meter), until it reaches zero, then closes the valve. The problem is, the solenoid I'm using at the moment, needs a high pressure (i.e mains pressure) to work correctly, so I need a valve that can work with gravity pressure, as I plan to use gravity to feed my mash tun.

Thanks in advance.

[Evanvine]

I have used these, they worked well.
http://www.ebay.co.uk/itm/DC12V-magneti ... OC:GB:3160

[Fil]

You might want to look for a motorised ball valve, the upside being they require zero back pressure to operate, the downside being cost (£20+) and the lag while the valve closes (2-3 secs). just means u need to measure the volume out during a close and subtract that from the target

[Waffty]

Many thanks for that.

Evanvine, do you know if those valves are food grade? And Fil do you have any details on the motorised valves, as I'm sure I can compensate for the delay in closing. As I'm not planning to use this for an automated system, more to give me a better idea of my sparge water to mash tun amounts, as currently, I either trust my sight glass, which I'm not 100% is correct or I use jugs, which is prone to failure, as I always loose count, fill at different levels and during all of this, I'm loosing temparature.

Thanks again.
Darren.

[Fil]

best i can do im afraid. ive not bought one..

http://www.ebay.co.uk/sch/i.html?_trksi ... &_from=R40

[Waffty]

Thanks for the info.

Order raised, I'll keep you updated with my progress

[Waffty]

I opted to go for one of these valves as they're specifically designed for gravity fed systems and have a nigh on instance shutting time. It's made of 6/6 Nylon and stainless steal, so from what I've read, it should all be ok for a food grade environment. Shipping from the US wasn't too bad, it was here in 7 days.

http://www.ebay.co.uk/itm/290763981675? ... 1423.l2649

As it's a little 'snappier' on the opening and closing than my previous valve, so I had to upgrade my power supply, as when it closed at the target point, it caused the flow controller to reset (voltage fluctuation). No such problems with the upgraded PSU

So all good.

[Fil]

good find. did u need a 2nd psu or just more amps?

[Waffty]

I did toy with the idea off using 2 PSU's but in the end I opted for a 12v 5A PSU, which I then feed through a three stage voltage regulator ie the regulator has a 12v input, which is then split into a 12v, 5v and variable output which I've set at 7v. So it's 12v for the valve, 5v for the flow sensor and 7v for the Arduino.

Before I used a 12v 2A PSU, which caused the valve trigger to rest then Arduino, which in turn caused the valve to fire again, causing it to constantly reset cycle.

I can try and did out the regulator and PSU combination if it's of any use?