G70 pump and high proof alcohol

[vsaks]

We have been using the G70 explosion proof pumps for pumping alcohol for the past two years.
I recently opened one of the pumps for cleaning and found the diaphragm breaking down.
This was used for pumping low wines (after stripping run) to the stills, so no solids.
I know these have been advertised as okay with alcohol, but it doesn't seem so.
Has any one else experienced the same issue ?

I have emailed the supplier I bought these from about replacement diaphragms.

[Silk City Distillers]

Curious - Do you leave pumps wet with alcohol or do you rinse with water after use?

[Dehner Distillery]

We use pumps like this. The key is to have the correct seals and diaphragm.

[vsaks]

2 hours ago, Silk City Distillers said:

Curious - Do you leave pumps wet with alcohol or do you rinse with water after use?

We leave pumps wet with alcohol. Don't rinse with water

[vsaks]

Buying from reputed vendors who are active here, I assumed the pumps had the right seals/diaphragms for use with high proof alcohol in distillery.

Do you ever open and clean your pumps ? I am wondering if others might have this issue too

1 hour ago, Dehner Distillery said:

We use pumps like this. The key is to have the correct seals and diaphragm.

[MichaelAtTCW]

@vsaks Not sure who you purchased from originally, but we stock the diaphragm repair kits here in Santa Rosa. You can give us a call at 707-963-9681 if you want to order. You should also order the check valve repair kit if you want to completely rebuild.

Because of their small size they can be tricky little buggers to rebuild properly, but Flojet produces a video demonstrating the process.

The G70's seals and diaphragms are fine for use with alcohol. They're Kalrez, which gets an 'A' rating on chemical compatibility charts. The G70 was originally intended as a general chemical transfer pump because of Kalrez's compatibility with over 1800 chemicals. It is compatible with more aggressive products than alcohol. That said, diaphragms are a wear parts and they will not last indefinitely. Leaving the pump wet with product without rinsing will decrease the lifespan of the wear parts on any product, so best to flush with water or a mild detergent of some kind after use.

2 hours ago, vsaks said:

Do you ever open and clean your pumps ? I am wondering if others might have this issue too

I can't speak for users in the field, but I know that we've sold many, many hundreds of G70s. Not just individually but as part of equipment that we make for distilleries. Looking at our sales history, we sell about one diaphragm kit a year, so my guess is the issue is not that widespread.

[Southernhighlander]

We have sold over 100 of them and have never had anyone order a diaphragm kit.  We just ordered a couple of the kits to keep in stock.