solenoidal valve not working under pressure - Page 1
Forum section: electronics / beginners

author: Adhith
author_rank: Frequent Contributor
timestamp: November 28, 2017, 12:00:24 pm
content: hello everyone..For my diy project I'm using a solenoid valve which is connected to a chamber made of 1 inch PVC pipe. After filling the chamber with acetic acid and baking soda the mechanical valve at the other end is quickly closed. The CO2 from the neutralization reaction builds up the pressure in the chamber. I'm adding a solenoid valve at the other end so that I can effectively use this pressure with an external power supply. But once the chamber is under pressure the valve is not opening properly but works if the chamber is empty. What would be the reason??The solenoid valve is rated for 0 to 120psi pressure and works on 24 volt. I have double checked the connection and all and ther is no wrong with the connection.

author: danadak
author_rank: Super Contributor
timestamp: November 28, 2017, 12:36:45 pm
content: Depends on the type of valve, gate, ball, globe, diaphragm..... as to whereand how the pressure acts. Sounds like the force in tank is greater than thesolenoid actuator force.For example if a gate valve force is pressure acting over area of gate. Thatstypically a lateral pressure, so solenoid has to overcome the force creatingfriction on the gate contact body interface. The gate has an area, x psi actingover the area, then that gets uptranslated by fact only small perimeter surfaceof gate is in contact with bodyRegards, Dana.

author: tecman
author_rank: Frequent Contributor
timestamp: November 28, 2017, 01:04:10 pm
content: Is it possible that the valve is piped backwards ?Some valve designs will only hold rated pressure in one directionpaul

author: Adhith
author_rank: Frequent Contributor
timestamp: November 28, 2017, 01:21:45 pm
content: Quote from: danadak on November 28, 2017, 12:36:45 pmThank you for you reply Dana. But as I mentioned it says that the valve could withstand a pressure up to 120PSI. whereas my setup could hardly produce somewhere around 30PSI or below. So technically it should work right??

author: Adhith
author_rank: Frequent Contributor
timestamp: November 28, 2017, 01:23:36 pm
content: Quote from: tecman on November 28, 2017, 01:04:10 pmYes I have attached the pipe in correct way(inlet & outlet) according to the inscription on the valve.

author: Adhith
author_rank: Frequent Contributor
timestamp: November 28, 2017, 01:25:38 pm
content: The solenoid valve works with the mixture of gas and liquid right?? or is it specifically for liquids only??

author: paulca
author_rank: Super Contributor
timestamp: November 28, 2017, 01:48:14 pm
content: I hope you didn't "fill the chamber" with acetic acid and baking soda. That would be a small pipe bomb.I used critic acid and sodium bicarb to generate CO2 for a planted fish tank and the required amounts to generate 3 bar of pressure where quite small. The system worked by two bottles cross feeding acid aqueous solution into the bicard aqueous solution where it reacted. When CO2 was used from the bicarb bottle the excess pressure in the acid bottle forced more acid over the pressure rose and a one way value allowed that to depressurize the acid bottle. The amount of acid entering the bicarb was a few drops from time to time.A 2 litre bottle with a few tea spoonfuls of each can generate well in excess of 200PSI and blow the bottle to pieces.I replace my CO2 reactor with a fire extinguisher (800-1000PSI) and a 12V solenoid value with an AC adapter which runs off a timer. However I run it off the low side of a regulator so it only controls about 1-2 Bar of pressure. The valve (ball value) being backwards rings a bell with similar users getting it to work, it had a directional arrow on it.You can run the chemical sums as to how many grams of CO2 will be produced from the reaction and you can find the pressure of a given volume and weight of gas. Alternatively drill a hole in your pipe and put a pressure gauge on it. You could be well in excess of the rated PSI of the valve.

author: Adhith
author_rank: Frequent Contributor
timestamp: November 28, 2017, 02:20:47 pm
content: Quote from: paulca on November 28, 2017, 01:48:14 pmThank you paulca for your valuable suggestions. I was referring a tutorial video by the renowned DIY magazine called MAKE. In the video they have attached a pressure gauge in the setup and it was around 20 PSI. also i'm using dilute acetic acid which I think wont be able to produce a much higher pressure and my setup hardly consist of around 300ml solution.

author: BBBbbb
author_rank: Unknown
timestamp: November 28, 2017, 04:25:34 pm
content: Do you have the ratings of the valve - mostly I'm interested in the specified inrush current and if you're supplying enough?Never worked with those small DIY hobby setups, but generally valves with those rating are usually a lot more massive than the one in you picture, at least those I've worked with.

author: jmelson
author_rank: Super Contributor
timestamp: November 28, 2017, 07:55:21 pm
content: Quote from: Adhith on November 28, 2017, 12:00:24 pmTypical solenoid valves require the solenoid to push AGAINST the inlet pressure to open the valve. So, the higher the pressure differential, the more force is required. Do you have any idea what pressure you are actually getting? If you are applying the full 24 V DC, then likely the pressure is greater than 120 PSI for the valve to fail to open.Jon

author: Gregg
author_rank: Super Contributor
timestamp: November 28, 2017, 08:52:23 pm
content: If your solenoid valve is a piloted type, the solenoid opens a tiny port that in turn uses system pressure to open the larger main valve port. You may have plugged the pilot port with baking soda.