Ask The Brewmasters

Hello,

I recently added horizontal lagering tanks to our cellar and noticed something that I have never seen before while following our standard SOP for purging vertical tanks. Specifically, I noticed that the pressure gauge on the CIP arm was very slow to show movement in the needle. To create an alternate reference point, I put a pressure gauge on the top of the tank where the PRV typically sits. The readings on the CIP arm gauge vs. the other at the top of the tank were different by ~4.5 PSI.

I can't logically deduce that the pressures are actually different at the two different points on the tank, but they must be. I can rule out any sort of blockages upstream of the gauge that was registering a lower PSI, and I can also rule out that either gauge is reading incorrectly. I determined this by placing the gauges on a tee and confirmed accuracy as compared to another pressure gauge, as well as the regulator at the CO2 source.

So, my question is two-part:

1. Has anyone ever noticed that pressure readings in a horizontal tank vary from the one location to another? I know this sounds crazy, but I have to ask this seemingly silly question because I am perplexed.
2. If in fact the horizontal orientation of the vessel materially affects how the tanks pressurize, I'd also expect that we might need to modify how we purge these tanks, as compared to standard vertical brite tanks. We typically purge through the bottom port, while venting into a bucket (air lock) at 5 PSI for 1 hour per 10 bbls of tank. This has worked beautifully on brite tanks, but with this new observation with the horizontals, I am wondering if anyone can speak to any needed modifications to our SOP.

For mention, these horizontal tanks have one very large spray ball in the center of the tank. The gauge that reads lower than expected is attached to the CIP arm, where exiting gas would go through the spray ball. The port where the gauge reads congruent to what I'd expect is at the top-front of the horizontal tank.

Thank you in advance for any insight regarding unique considerations regarding pressurizing and purging horizontal tanks. 

Travis,

Quick question.  Are your pressure readings being taken with pressure being applied to the tank but with no air/CO2 flow in or out of the tank?  

Hello,

I recently added horizontal lagering tanks to our cellar and noticed something that I have never seen before while following our standard SOP for purging vertical tanks. Specifically, I noticed that the pressure gauge on the CIP arm was very slow to show movement in the needle. To create an alternate reference point, I put a pressure gauge on the top of the tank where the PRV typically sits. The readings on the CIP arm gauge vs. the other at the top of the tank were different by ~4.5 PSI.

I can't logically deduce that the pressures are actually different at the two different points on the tank, but they must be. I can rule out any sort of blockages upstream of the gauge that was registering a lower PSI, and I can also rule out that either gauge is reading incorrectly. I determined this by placing the gauges on a tee and confirmed accuracy as compared to another pressure gauge, as well as the regulator at the CO2 source.

So, my question is two-part:

1. Has anyone ever noticed that pressure readings in a horizontal tank vary from the one location to another? I know this sounds crazy, but I have to ask this seemingly silly question because I am perplexed.
2. If in fact the horizontal orientation of the vessel materially affects how the tanks pressurize, I'd also expect that we might need to modify how we purge these tanks, as compared to standard vertical brite tanks. We typically purge through the bottom port, while venting into a bucket (air lock) at 5 PSI for 1 hour per 10 bbls of tank. This has worked beautifully on brite tanks, but with this new observation with the horizontals, I am wondering if anyone can speak to any needed modifications to our SOP.

For mention, these horizontal tanks have one very large spray ball in the center of the tank. The gauge that reads lower than expected is attached to the CIP arm, where exiting gas would go through the spray ball. The port where the gauge reads congruent to what I'd expect is at the top-front of the horizontal tank.

Thank you in advance for any insight regarding unique considerations regarding pressurizing and purging horizontal tanks. 

Yes, we have noticed the discrepancy between the locations of the pressure gauges during active pressurization and during static conditions.

Again, I know the question seems weird, but has anyone seen such a phenomenon in horizontal tanks? Alternatively, would the spray ball be considered a restriction that would cause a lower reading at a gauge further downstream from the spray ball? As I mentioned before, there are no obstructions in the spray ball itself.

Thank you, everyone

Travis,

Quick question.  Are your pressure readings being taken with pressure being applied to the tank but with no air/CO2 flow in or out of the tank?  

Hello,

I recently added horizontal lagering tanks to our cellar and noticed something that I have never seen before while following our standard SOP for purging vertical tanks. Specifically, I noticed that the pressure gauge on the CIP arm was very slow to show movement in the needle. To create an alternate reference point, I put a pressure gauge on the top of the tank where the PRV typically sits. The readings on the CIP arm gauge vs. the other at the top of the tank were different by ~4.5 PSI.

I can't logically deduce that the pressures are actually different at the two different points on the tank, but they must be. I can rule out any sort of blockages upstream of the gauge that was registering a lower PSI, and I can also rule out that either gauge is reading incorrectly. I determined this by placing the gauges on a tee and confirmed accuracy as compared to another pressure gauge, as well as the regulator at the CO2 source.

So, my question is two-part:

1. Has anyone ever noticed that pressure readings in a horizontal tank vary from the one location to another? I know this sounds crazy, but I have to ask this seemingly silly question because I am perplexed.
2. If in fact the horizontal orientation of the vessel materially affects how the tanks pressurize, I'd also expect that we might need to modify how we purge these tanks, as compared to standard vertical brite tanks. We typically purge through the bottom port, while venting into a bucket (air lock) at 5 PSI for 1 hour per 10 bbls of tank. This has worked beautifully on brite tanks, but with this new observation with the horizontals, I am wondering if anyone can speak to any needed modifications to our SOP.

For mention, these horizontal tanks have one very large spray ball in the center of the tank. The gauge that reads lower than expected is attached to the CIP arm, where exiting gas would go through the spray ball. The port where the gauge reads congruent to what I'd expect is at the top-front of the horizontal tank.

Thank you in advance for any insight regarding unique considerations regarding pressurizing and purging horizontal tanks.