First, if you caught the joke in the title, 2 points. If not, find your weird friend that is into Puns and Acronyms. They will be happy to mansplain it. And yes, it was a conscientious decision to change the last word to Silly, because the other S-word is one I am loath to use toward any human, until they have gone out of their way to earn it. The use of the word Stupid, when aimed at another human, is simply evil. The amount of damage it does to society, especially to children, is unfathomable, so should it appear in my writing, please understand that I equate it, emotionally, to racial and sexist slurs. If I use it, I intend to hurt the target.
Since I blogged on Beer Gas, several people have asked something to the effect of,"If not Beer Gas, what should I do?
If you are coming across this post without prior knowledge of Long Draw dispense methods, the broad gist is this: To push beer over any real distance [more than 10-15 feet/3-5 m], you need to augment the pressure applied, to overcome resistance inherent in the tubing, and to prevent foam and waste. The most common method is to blend an inert gas in, with your CO². N²[pure Nitrogen] is the gas most commonly used.. Argon is also used, but this is uncommon, and adds levels of difficulty and expense. The second method is to augment pressure mechanically, by way of a pump.
In the afore mentioned blog, I touched on the alternative of blending gas on site, from cylinders of Pure N² and Pure CO², because, once in gaseous form, at the range of temperatures we are likely to inhabit, these gasses will perform as perfect gasses, and mix in near perfect ratio, so long as they are in motion. If stagnant for a long enough period, they will separate by weight, but truly stagnant air is really rare. Mixing gas on site is quite common, but this requires maintaining a small army of Nitrogen cylinders, because the storage of N² is much less efficient than CO², The expansion rate of CO² is 2.5 times that of N². To put this into practical terms, if you are working out of equal size cylinders, you would expend 2 to 3 times as many N² cylinders, as compared to CO². And as real estate, within most restaurants, is at a premium, this can be cumbersome and daunting.
If one wishes to use N², while avoiding cylinders, one can purchase or Rent/Lease a Nitrogen Generator system, which is is often equipped with a blender built in. They can be obtained without a Blender, should you already have one. This still requires one to have a storage tank and a back-up tank, but often reduces the overall footprint. Additionally, the generator and storage tanks are commonly located in places otherwise impractical for cylinder storage, such as in a basement, ceiling, or upper floor. Gas providers are reluctant to move cylinders up and down stairs. The most common Blend Configurations are 60% CO², and 25% CO². The remaining percentages should be N², as this is the gas by which the device was calibrated. Using any gas or blend other than Nitrogen can cause issues which range from the beer carbonation level being slightly lean or rich, all the way to destruction of the Blender, and spoiled kegs. Let me take two sentences to reiterate: NEVER use air, or a blend of air, or oxygen, to pressurize a keg, as it will ruin the beer. Air is only permissible to use as a power source for pneumatic pumps, if filtered and dried, and only because the air never contacts the product but is only powering the mechanism.
How it works: Most beverage pumps are double diaphragm pumps. This consists of a mechanism that oscillates two diaphragms, causing them to shrink and enlarge chambers on each end. a series of 1-way valves that only allows flow in 1 direction. The oscillation ensures that the pumping is constant. As one chamber pushes product out, the other is drawing in more product from the source.
How we apply it: Every beer is a little different. CO2 content may vary from beer to beer. Additionally some Beers are more sensitive than others because they are light in body and have trouble containing the CO². Or maybe they are unfiltered, creating microscopic internal surface areas to help CO² bubbles collect, and escape solution. In an ideal world, we apply pure CO² to the keg at the pressure which ensures perfect carbonation maintenance for a particular beer or group of beers. Most will need a setting between 12 and 15 PSI. Provided the kegs are maintaining an internal beer temp of 2°C[±1°] / 36°F[±2°], this will be enough pressure to deliver the beer to the pump, without CO² break-out. Whatever additional pressure is required to get the beer to Its destination is provided by the pump. And since the next best defense against foamy beer, after keeping it cold, is to keep the squeeze on it, pressure is our friend. It disallows gaps and low pressure pockets, whereby CO² would be all too happy to expand and fill the void. I often equate beer to a newborn. We want to keep it at Its ideal temp and we want to swaddle it, so it doesn't flail about and upset or injure Itself.
Pneumatic[Gas/air] driven pumps have a minimum operating pressure of 8-12 PSI. Unfortunately, we can't run them at the minimum. We have to allow for regulators that are inaccurate, or that experience a pressure drop under load. I have found that a minimum setting of 15 PSI will give enough buffer to allow for gas supply issues. When you take into account a mechanical loss of about 25%, the fluid output pressure on a 15 PSI pump setting is around 11 psi. Add this to your Maximum Keg pressure of 16 PSI, and you get 27 PSI. When you restrict your beer system, to ensure a correct flow rate of 2 oz or 59 ml/sec, 27 PSI is the minimum I would recommend for a beer system within 1000 Feet, or 300 m of sea level. But as a person who is wary of skirting the line on any minimum or maximum, I tend to target dispense pressures values of 30-36 psi for beer pump systems. You can go much higher, where required, but I find that 36 PSI will serve 90% of applications. 200 feet of 5/16" id poly barrier beer tubing, and 15 PSI of Restriction value in a tower will dispense at 35 PSI Fluid Pressure, and deliver 2 oz a second for up to 2 faucets. It can handle 3 faucets at 1.5-1.8 oz/sec, provided the system is perfectly balanced.
Every Pump will need a FOB/Empty Keg Detector, but for any system over 25-30 feet, this sis usually already a given. The number of regulators required will vary, depending on the scope of beer styles, the number of faucets vs. kegs, the overall system pressure requirements, and the volume of beer sold. Generally, I recommend a regulator for every other keg, and another, for every 4 pumps. This usually provides enough flexibility for most offerings and locations. And if this is laid out correctly, it would be quite easy to add additional regulators, should they be required at a later date. One could also, preemptively beef up the portions of the system that are most likely to need it, such as the fast movers, or the "guest" and seasonal faucets that might require abnormal tuning. The wonderful thing about a beer system is that the return on investment is usually measured in weeks, as opposed to quarters, or years. With a profitability ranging from $400-800, per keg, depending on beer and market, it usually takes 3-4 kegs, to pay for each faucet.
A real-world example: I helped install a beer system that cost the client $88,000. It was a busy, storied, sports bar that had burned down, but was, thankfully, correctly insured. They reopened with 48 Faucets, pouring 20 different beers. They had 2 , massive, 20-faucet towers at the main bar, and a VIP/event space Bar, with Its own 8-faucet tower. In the 3 days of their opening weekend , they blew 88 1/2 Barrel Kegs. Knowing what the kegs cost, and their Pint pricing, conservatively, they made at least $550, per keg. By the end of the following weekend, the beer system was in the Black. 6 months in, they were still moving more than 50 kegs a week. The beer system was still paying for Itself every 3-4 weeks. So adding a regulator or two, to improve performance, and reduce waste,[a cost of a about $200 each, installed) is barely a blip. Even if you count it, only against reduction of waste, most improvements will pay for themselves within 3 or 4 weeks. If not, chances are, the beer on that line is not moving quickly enough to keep in the line up.
The benefits: As previously stated, not all beers need the same amount of CO2. A beer pump allows your to better tune the CO2 content to fit the style. Even if you have multiple kegs on each keg reg, you can group the beers by similar CO2 requirements, because, really, there is a pretty narrow range of pressures, and most beers will be set between 12 and 14 PSI, on the keg. If a 4 pump bank is all set on the same Keg Pressure, it is likely the bank will all be run by a single regulator for pump pressure, as well. Simply set your Kegs to the pressure required to maintain correct Carbonation and deliver the beer to the pump, in-tact. The you turn up the pumps until the entire bank is cooperating.
The pumps can be powered by any clean, dry gas you might have, be it CO2, Nitrogen, or even compressed air. The gas driving the pump will never interact with the beer, or other product. Also, as a demand pump that can deliver up to 4.5 Gallons a minute, it can easily run 2 faucets at once, and sometimes, even a 3rd, though they will run a little slow. This means that running your pumps can be managed around your gas supply, and is easily backed up. If your market is such that you have mini-bulk CO2 that is both abundant and inexpensive, then you can use this to power your pumps, provided you vent the exhaust to a safe area. Alternatively, if CO2 is expensive, or simply difficult to replenish, where you are, you can use an Air compressor to power the pumps. Many Breweries already possess large Air Compressors for their Packaging Lines, which have ample capacity to run a few beer pumps. I would still recommend venting the pumps to a space with good Ventilation, or to an HVAC air return. This will then allow you to tie in a switch-over to the CO2, so that, should the Air Compressor Fail, or temporarily need all of the capacity to run the packaging line, you can run the pumps on CO2 in the interim, with the flip[ of a valve or two.
Many Beverage pumps, such as Flojet G-Series Pumps, are self priming. They don't require cleaning pumps or pots. All you need is a clean bucket to mix your solution in, and the pump will do the work of moving the cleaner. Cleaning pots start at $400, for 4 lines. Cleaning Pumps can run well over $1000. In the restaurant business, buckets are often free. I don't think I ever purchased a bucket during my 10+ years as a field technician.
Higher pressure systems are more forgiving of other, borderline issues. How often has one of your employees thrown on a keg of Coors light, or other temperature sensitive beer, when it is 1°-2° warmer than it should be? If your system has less than 25 pounds of restriction value, there is a good chance that something like a light lager, a Wheat, or a Hazy beer, when served at 39.5°F / 3.2°C will fall apart inside the line, before it even reaches the faucet. The additional squeeze provided by the High restriction the pump is operating against is enough to keep something borderline packed, all the way to the faucet. You might get a little extra head, but without this, it would easily have been half a glass of pure foam, but dispensed in spurts that make filling a glass near impossible. Every 3 oz of foam is 1 oz of beer. It can add up quick. 1 oz of waste, per 16 glass of beer means a loss of nearly 1 gallon of a 15.5 gallon domestic keg. That's 2 Pitchers that go down the drain, but only after frustrating Staff and Guests.
Pumps reduce or eliminate Gas Cylinders. Nitrogen and Beer gas cylinders hold a lot less gas than their equivalently sized CO2 counterparts. CO2 stores as a liquid, and packs at an efficiency that is 2.5-3 times greater than Nitrogen , and at 1/3 the pressure in the vessel.
My job as a Draft Equipment tech is to put a beer in the glass as the brewer intended it to be enjoyed. It the brewer wanted it to have Nitrogen, they would have added it already. Every Beer Tech I have ever met that thinks that a mixed gas cylinder is a good idea is either one that sells Beer Gas, or has been trained by someone who sells beer gas. Pumps may seem complicated, but when you actually begin reading up on how these gasses interact with the beer, the environment, and other gasses, a pneumatic pump seems a lot easier to explain. Critical point physics is nothing to be sneered at.
The short of it is this: Pumps are cheaper to operate than blended or mixed gas systems of any type.
Pumps are more dependable than Blended gas.
Pumps don't add anything to the beer that wasn't already there.
Pumps consistently out perform mixed gas in terms of waste reduction and beer quality.
Guess what my next question is.
Cheers.
Dan B
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