Sodium Filled Valves

Warbird Kid · **Posted:** Wed Jun 20, 2012 8:37 am

Hey all,

I had a question for the WIX Maintenance Brain Trust.

We have some sodium filled valves in the back storage, and I was hoping to repurpose them for a potential sculpture. BUT I heard that these sodium filled valves are quite dangerous if they explode. So I'm wondering if anyone here knows just how dangerous, or not they are to try and work with. Would it not be a good idea to use a welder on the valve?

Any help would be great and appreciated.

Chris
the uneducated

Cherrybomber13 · **Posted:** Wed Jun 20, 2012 8:44 am

Good question Chris. Safety First!

PropsRule · **Posted:** Wed Jun 20, 2012 9:15 am

When I was an apprentice it was made very clear to me to never drill into a sodium filled valve for fear of an explosion. In hindsight it looks like the crew chief knew how a young apprentice's curiosity could get them into all kinds of trouble. I think he was right...it's been a couple decades since then and from time to time I still wonder what a sodium filled valve looks like inside. Ah well...

For this reason I wouldn't try welding one either. I'm looking forward to seeing what others have to say about this too.

famvburg · **Joined:** Fri Oct 07, 2005 9:41 am **Posts:** 540

The only bad thing I remember being told about sodium filled valves was if one breaks or is broken, don't get the sodium on my skin as it can cause a bad burn. that was about 35+ years ago and I still remember it, but that's all.

F4U-7 · **Posted:** Wed Jun 20, 2012 9:51 am

From the Wikipedia page...

Care is required in handling elemental sodium, as it is potentially explosive and generates flammable hydrogen and caustic sodium hydroxide upon contact with water; powdered sodium may combust spontaneously in air or oxygen.[60] Excess sodium can be safely removed by hydrolysis in a ventilated cabinet; this is typically done by sequential treatment with isopropanol, ethanol and water. Isopropanol reacts very slowly, generating the corresponding alkoxide and hydrogen.[61] Fire extinguishers based on water accelerate sodium fires; those based on carbon dioxide and bromochlorodifluoromethane lose their effectiveness when they dissipate. An effective extinguishing agent is Met-L-X, which comprises approximately 5% Saran in sodium chloride together with flow agents; it is most commonly hand-applied with a scoop. Other materials include Lith+, which has graphite powder and an organophosphate flame retardant, and dry sand.

The Inspector · **Posted:** Wed Jun 20, 2012 9:59 am

Wasn't there a recent tread about this in either the Maintenance or Vintage Hangar? I know I did several posts (as did a few other folks) against how the questioner wanted to remove the sodium from the valve stems, the moisture from your fingers is enough to start a REALLY spectacular fire.
Chris ya might want to do some diggin' into those two areas. Standard practices for Sodium Valves was to dig a fairly deep hole in the grass between the runways and bury them.

b29flteng · **Posted:** Wed Jun 20, 2012 10:08 am

I was told in A&P school to dispose of them to drop them in the deep part of a lake or ocean.

Cherrybomber13 · **Posted:** Wed Jun 20, 2012 10:17 am

So.. Anyone have 4 (big engine) non sodium filled valves that they might donate to the Museum for a project we are working on? no need for airworthy, just not all bent up.

Chris, lets get the dingy and some oars...

Warbird Kid · **Posted:** Wed Jun 20, 2012 10:19 am

Hmmm so it sounds not so good. Let me ask you guys this then,

After searching WIX I found this post from Brian B:

Quote:

Like to think that I also prevented a serious problem at the scrap yard by stopping the sodium filled valves from being torched or sent to the smelter. We mounted about 100 of the valves on walnut plaques and gave them to customers at Lockheed and Boeing.

This sounds as close to what I was envisioning. SO if I were not to do anything damaging / altering to the sodium valves, just cleaning them up, do you think they would be safe in a sculpture if they were mounted by wire, hot glue, or something else to that effect? Would this be something hazardous and I should just forget about it, or would this be relatively safe considering no one tries to throw the thing across the room when its finished?

Chris
the astute

51fixer · **Posted:** Wed Jun 20, 2012 10:22 am

Use some intake valves. I don't think they have the sodium inside.
Roush makes new exhaust valves for the Merlin and adds the sodium under a vacuum in a special cabinet.

WIXerGreg · **Posted:** Wed Jun 20, 2012 11:39 am

I'm not an aircraft engine expert, but I know in the automotive world the sodium is pretty much only used in the exhaust valves because they're the ones that run the hottest, the intake valves are cooled by the incoming charge.

On the safety side of it, we've been told that even a correctly placed hammer smack on the end of the valve stem could set one off. Never tried it!

Cherrybomber13 · **Posted:** Wed Jun 20, 2012 12:07 pm

Stupid question but visually any way to tell the difference on a 1300 Radial intake and exhaust valve that are new in an unmarked cardboard box? They came in years ago with a donation of engine parts.

PbyCat-Guy · **Posted:** Wed Jun 20, 2012 12:37 pm

Is it time for another episode of the "Myth Busters"?

The Inspector · **Posted:** Wed Jun 20, 2012 12:47 pm

Would it include a cannon, a bowling ball, several homes, and a gun range?? :wink:

Seriously Drew, a quick peek in the overhaul manual under 'limits' should give the nominal dimensions of the parts or examining the rocker end of the valve you should see some evidence of welding and finishing which would indicate which is which.

Cherrybomber13 · **Posted:** Wed Jun 20, 2012 1:31 pm

Cool. Thanks for all the great info. Chris and I will check them out tomorrow night at the shop. At lest Matt our welding guy wont need to have an unnecessary trip to the hospital

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Sodium Filled Valves

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