# Water valve for over 120C temperature

I am making a project where i need to put a water valve below the tank and then need to open it automatically but the problem is that already available brass electric valves aren't good enough to handle the 120C temp besides i heard that brass isnt good for something that will be consumed by Humans later. And that overtime brass get mixed up in material and it will be consumed. what's the best solution for this problem ?

i was thinking maybe is there anyway that i can put a motor or something on this steel valve and remove this handle and then open it with that motor or something

• How is 120 C water/steam being used for human consumption? In my experience it is unusual for residential hot water to reach more than 70 C, given how you can easily be scalded at temperatures of even 50 or 60 C Commented Feb 10, 2017 at 16:55
• i wrote 120 C just to be on the safe side because below the tank there will be a heating element near valve that means temperature there is gonna be higher than the rest of the tank. Commented Feb 10, 2017 at 16:59
• Have you considered insulating the valve from the heat source as an alternative? 120 is about the boiling point at 2 atm. That seems like cause for concern beyond just the valve. Keep in mind that being too liberal with your safety factors can lead to poor design choices - can you fully justify the 120 assumption?
– Air
Commented Feb 10, 2017 at 17:13
• i just want it to be more than i needed just to make it strong, yes i need something between 95 to 100 but it should be stronger than that and that's why i mentioned 120 C Commented Feb 10, 2017 at 17:20
• I think what you are trying to say is that the water is going to be ~95C, but because of conduction from the heating element you think the metal might be 120C. What kind of heating element is it? If it's a bunsen burner and you are literally applying flame to the outside of the container, then I think a 25C difference between the metal and the water is reasonable. But if it's an electrical element immersed in the water, I think the difference between the case and water temperature would not be so extreme. Commented Feb 11, 2017 at 22:15

I suggest an air actuated stainless steel ball valve. There are literally tens of thousands(if not more) of available options, including kits that will refit an existing manual ball valve to be air actuated.

My preferred source for this type of valve and accessorie is Parker. Start Here and you can use their configurator to get exactly what you want. If you can't find it, call them, they can make it. Sometimes that can get expensive though. There are other vendors and as with many things, you can order such things from McMaster-Carr

Solenoid valves are another option, but they are typically limited in tubing size. Again, McMaster-Carr has a wide selection and a tool that lets you search by your particular requirements.

As to the concern over brass contaminating water, it's used all over the place in domestic faucets and fittings. That said, brass does contain small amounts of lead that can leach into water even when the material is compliant

Stainless steel doesn't have that problem, but is more expensive.

• yes stainless steel is something that i had in mind but it doesn't come with the any electric handle opening mechanism should i put a servo motor on it to open it electrically then ? because of the fact that its purely made of Stainless steel that means it can handle 98 C to 120 C so putting motor on the handle is a good thing ? Commented Feb 10, 2017 at 16:38
• @davidweb just because it's stainless steel it doesn't mean it will hold up. Different valves are designed differently. That said attaching your own actuator to a valve that is rated for your conditions is pretty straight forward (controlling it may not be). A lot of valves have a way to hook in an actuator (especially control valves that can come with their own). There are plenty of options for high temp control valves.
– JMac
Commented Feb 10, 2017 at 16:44
• I posted a link in my answer to solenoid actuated valves. No, just because a valve is stainless steel doesn't mean that it can handle a higher temperature, brass valves can be as well, but if you're running something people will drink, stainless steel might be a better choice. Cobbling together a motor onto the valve in your picture is something you can do, but if I were you, I'd just buy a solenoid valve or a retrofit kit and call it a day. Commented Feb 10, 2017 at 16:49

120C water is steam at standard conditions. You should look into steam valves or vales designed for a steam/water mixture.

Modifying the valve opening mechanism won't make the actual valve any stronger, so I don't suggest that.

AFAIK a lot of residential pipe fittings are brass, though it may only be safe in specific temperature ranges.

• yes 120C is basically steam but it should be around 98 C actually but because it will be below the jug near the heating element so i am going with 120 C to be on the safe side. Commented Feb 10, 2017 at 16:35