DIY auto purge

[HeXx]

Per the title.
I'm working on a autopruging system for compressors that don't have one.
I started the project trying to find high pressure valve electronically actuated but that would make a system quite expensive very fast.
So here is my first prototype.

Inputs are welcome on how could this be improved if needed.
Very simple without needing to modify anything in the system.
I expect everything to be under 100 euros for 3 valves.

Configuration page for up to 6 valves:

Cheers

 

[Johnoly]

Auto-drains are both a blessing & a maintenance pain.
Is your design for 'actuation' while the compressor is running continuously or is it just for after it is shut down? The amount of time that a screw type valve is open can lose alot of pressure for the compressor to 'rebuild' it's pressure from the drain opening. That's why most autodrains {not all } use a cone shaped Poppet valve where the shape of the cone is actually forced back closed from the high pressure. But that valve needs to be regularly cleaned because any tiny bit of debris inside the moisture will block a complete closure. Autodrains save alot of time so you don't have to monitor the compressor run. But they are a pain when the valve gets clogged or broken.

 

[HeXx]

Auto-drains are both a blessing & a maintenance pain.
Is your design for 'actuation' while the compressor is running continuously or is it just for after it is shut down? The amount of time that a screw type valve is open can lose alot of pressure for the compressor to 'rebuild' it's pressure from the drain opening. That's why most autodrains {not all } use a cone shaped Poppet valve where the shape of the cone is actually forced back closed from the high pressure. But that valve needs to be regularly cleaned because any tiny bit of debris inside the moisture will block a complete closure. Autodrains save alot of time so you don't have to monitor the compressor run. But they are a pain when the valve gets clogged or broken.

It's for using while running.
In the image below shows the configuration. For example, for each valve you would configure in the first box how many miliseconds the valve is to be turned to the open position, lets say 500 miliseconds to open the valve (turn the tap countreclockwise), then how many miliseconds to stay open (lets say 100 miliseconds so it has time to drain the condensate) next would be how many miliseconds to close the valve (clockwise, lets assume 500 miliseconds that was the time it took to open +20 miliseconds to tighten the valve shut) then how long it should wait to pruge the next valve, and so on. Lastly, on the last field, when should the cycle be done again. From what I read, 3 to 5 minutes is an appropriate time but varies with compressor times.

What I expect from this design is its simplicity, does not need to modify anything on the compressor and you can still turn the valves by hand.

 

[Agro]

Looks great indeed. And less than 100 Euro for 3 valves is perfect!

 

[InWay2Deep]

What are you using to control the servo?

 

[HeXx]

What are you using to control the servo?

A PWM signal from an ESP8266.
Configuration is done via web interface connecting to the ESP.

 

[Snusmumrik]

Great thing. Me use DIN rail timer and electromagnetic normal closed 300bar valve from aliexpress.

 

[HeXx]

Great thing. Me use DIN rail timer and electromagnetic normal closed 300bar valve from aliexpress.

How much are those? Can you share a link?

 

[Snusmumrik]

How much are those? Can you share a link?

Hochdruck-Autowasch-Magnetventil aus Edelstahl 304, 0–300 bar (Details Siehe Spezifikationstisch), 1/4 Zoll normalerweise geschlossen oder offen - AliExpress 13 - valve
Samwha-Dsp ERX-10 Multifunktionale Timer Relais - AliExpress 13 - timer

 

[HeXx]

Hochdruck-Autowasch-Magnetventil aus Edelstahl 304, 0–300 bar (Details Siehe Spezifikationstisch), 1/4 Zoll normalerweise geschlossen oder offen - AliExpress 13 - valve
Samwha-Dsp ERX-10 Multifunktionale Timer Relais - AliExpress 13 - timer

Yep. That becomes expensive really fast, and I would say adds a failure point and more maintenance.
At the begining I was looking into modifying a compressor with this kind of valve but with a servo direct to the purge tap is cheaper and "bullet proof"