Zahm & Nagel Co. has been manufacturing carbonating equipment for the beverage industry for over sixty years. The system consists of a carbonating stone, holder and a connecting fitting which is installed inside and near the bottom of the tank. A CO2 gas line is attached to the connecting fitting and the gas is then pushed through the carbonating stone and dispensed into the beverage. The veil of very fine CO2 gas bubbles that rise from the stone resembles those produced by beer fermenting under pressure. This method of carbonation removes most of the dissolved air in the beverage, which results in improved keeping quality of the beer.

Generally, one 2" x 10" stone (P.N. 16040) will carbonate up to 100 barrels of beer within a 24 hour period. The amount of time required for complete carbonating depends on the size of the tank and the temperature of the beverage being carbonated. Recently, Zahm & Nagel Co. has begun producing smaller diameter stainless steel stones which are used by microbreweries and brewpubs to achieve the same consistent results in smaller vessels.

The various components of the carbonating system are as follows:

The Carbonating Stone
Available in ceramic (Series 16000) or sintered stainless steel (Series 19000). The ceramic stone (P.N. 16040) measures 2" in diameter x10" long and is used by many of the major brewers and microbrewers. The sintered stainless steel stone measures 1" diameter x 4" long (P.N. 19000-4), 6" long (P.N. 19000-6) or 8" long (P.N. 19000-8), and is used by smaller microbreweries and brewpubs.

The Holder
There are two types of holders for Zahm & Nagel stones. P.N. 16005 holder is used with the P.N. 16040 ceramic stone. It consists of a central stainless steel tube, end gaskets, locking handle and check valve assembly. The stone is placed between the gaskets and tightened in place with the locking handle. The holders for the stainless steel stones are included with the stones. They are similar but somewhat smaller than the P.N. 16005 ceramic stone holders.

Connection Fittings
There are many types of fittings available to connect the stone holder to the wall of the tank. The most commonly used are as follows:

P.N. 16010 stainless steel elbow is a standard bottom-mounting elbow that is clamped into place in the bottom of the tank. The holder and stone are then screwed into the hose nut of the elbow until tight against the internal hose nut gasket. This #16010 elbow may be used to mount either ceramic or stainless steel stones.

P.N. 16028 side mounting assembly (for outside access) may also be used with either ceramic or stainless steel stones. It uses an extension holder and triclamp that is welded to the side of the tank. To remove the holder and stone, the locking clamps are loosened and the entire stone and holder withdrawn from the tank.

Other Related Equipment:
Non -Freezing Reducing Valves (P.N. 16500):  This valve is designed with an electrical heating element located directly under the seat of the valve, which keeps the valve from freezing and yet does not heat the gas that passes. It will allow the passage of gas temperatures below freezing without interfering with the operation of the valve.  Constructed of high pressure bronze, this valve is suitable for reducing gas pressure from 250 lbs to carbonating pressures.  It is furnished complete with a 100 lb. pressure gauge and ½” or ¾” pipe connections.