# Question on eyewash plumbing



## SharpPlumbing (Feb 1, 2016)

I'm new to eyewashes with a thermostatic mixing valves. Has anyone have experience with plumbing these in? It is a Speakman SE-370 Thermostatic mixing valve. Do you just plumb the hot and cold into it and hook the blended water to the eyewash. or does the have to be some kind of recirc loop just for the eyewash to keep it at a constant temp? The engineer only spec. for a recirc loop for the whole building, nothing for the 2 eyewashes.
The only reason I question it is Speakmans website makes it look like the recirc is supposed to loop through the eyewahes???
Any help is greatly appreciated


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## SharpPlumbing (Feb 1, 2016)

I checked the code requirements and it states that the water must be between 60-100F. It does not state if that is instantly, or if you have a few seconds for the water to reach that range. These eyewashes are in the lab of a small medical clinic, I just want to make sure I get this right. Both of the eyewashes will be within 15' of a recirculated hotwater line. I would think it would only take 3-5 seconds for the water to reach the proper temp range.


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## sparky (Jan 8, 2014)

SharpPlumbing said:


> I'm new to eyewashes with a thermostatic mixing valves. Has anyone have experience with plumbing these in? It is a Speakman SE-370 Thermostatic mixing valve. Do you just plumb the hot and cold into it and hook the blended water to the eyewash. or does the have to be some kind of recirc loop just for the eyewash to keep it at a constant temp? The engineer only spec. for a recirc loop for the whole building, nothing for the 2 eyewashes.
> The only reason I question it is Speakmans website makes it look like the recirc is supposed to loop through the eyewahes???
> Any help is greatly appreciated


No loop needed,it will mix as soon as handle is pulled or pushed down,usually you just need cold water to an eyewash station as cold water neutralizes acids and things like that better than mixed water


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## plumbdrum (Nov 30, 2013)

What does YOUR code book say? You could have. 20 different answers here.


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## Paul4813 (Nov 28, 2015)

Those eyewash stations come with a mixing valve because they require hot and cold, normally it mixes to around 90 degrees. And yes, it should just plumb like you said, blended water up to the valve or lever


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## bct p&h (Jan 19, 2013)

Mixing valve should be set depending on what chemicals are being used in the area. 
Check your local code on recirc. I'm assuming that since there isn't an emergency shower the chemicals aren't that bad or there isn't going to be a large amount of them. Chances are you won't need the recirc but health department may require to avoid stagnation.


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## Flyout95 (Apr 13, 2012)

We pipe a circ to the mixing valve. Thought is if someone pulls that for chemicals, you need safe water instantly.


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## SharpPlumbing (Feb 1, 2016)

The goofy thing is that there is no state plumbing code here. The health department only checks that there is an eyewash station and that the wash is functional and the cover caps are present and covering the fountains. I talked to another plumber and, well, he just chuckled and said "your good":no:. Our state needs to adopt a state wide universal plumbing code. We have no code, no inspectors, nothing. Any joe blow can pick up pipe wrench in this state and call himself a plumber:furious:, Except in the major cities, they do have city codes and inspectors. Out here in the sticks were on our own. Anyways this is a rural health clinic, so there not using anything anymore dangerous than what anybody would have in there home. The only reason there is a mixing valve is that universal code calls for tepid water.


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## GAN (Jul 10, 2012)

plumbdrum said:


> What does YOUR code book say? You could have. 20 different answers here.


Plus OSHA regulations depending on what you are attempting to safe guard from.


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## Ryan M (Dec 8, 2013)

Honestly man don't over think it. Depending on the unit your installing (eye wash shower combo) there needs to be enough water to run both sprayers at the same time. The water needs to be Luke warm so body temperature. I actually just installed one today and I fed it with a 3/4" line because it was near by but you could probably get away with 1/2" sometimes you can only work with whats there.

Biggest thing is placement of unit and temperature of water also its nice to have a floor drain near by with a 11/4" indirect drain connection for the eye wash its shelf.

Cheers mate.


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## GAN (Jul 10, 2012)

Excerpt:


Tepid water can be delivered to Eyewash and Shower flushing stations by many different means. The most common method is by installing Thermostatic Mixing Valves (TMV's) or Water Tempering Valves. These valves blend hot and cold water to provide a comfortable flushing fluid within the temperature range as defined by ANSI. Access to hot water is a necessary component and can be achieved through traditional water heaters, on-demand water heaters (tankless water heaters), and re-circulating systems. It's important to note that standard water mixing valves should not be used for the purpose of providing tepid water to Emergency Eyewash and Drench Shower Stations. Mixing valves designed specifically for Eyewash related products include a hot water shut-off to prevent accidental scalding, and a cold-water bypass to ensure the delivery of flushing fluids in the event that the hot water supply fails.


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