KEGS: Ball Locks vs Pin Locks.
With over 25 years experience, I will try to dispel various rumors and incorrect information that have become common online.
A little history will help in the understanding of these types of “beverage transfer tanks” as they were originally called. Early versions, Firestone & John Wood manufactured tanks. The tanks used in a system started by Coke around 1957-1958, called a Post-Mix, in which the syrup was delivered to businesses that then added the water & CO2 to carbonate the drink as it was delivered to your cup. Pin locks were exclusive to Coke and Ball Locks were considered general beverage & PEPSI
#1 would be that PIN LOCKS are less desirable that Ball Locks. This started out based on the availability of used ball lock tanks of which were much easier to find and the stockpiles were huge. Once the era of Post-Mix ended, the beverage companies starting wholesaling the tanks, with millions of them going overseas. These countries still used the Post-Mix systems. At this time your finding ball lock tanks increasingly difficult to find online or local suppliers. Prices have been rising, add shipping if online, and your paying a lot more than years ago when these were $3-$10. It is not uncommon to see prices from $25 to $50 or more now depending on type, condition and whether you have to clean or replace O-rings, seals and poppet’s. Premiums are charged for the best-used tanks, while lower prices will soon mean rougher condition or not being exactly what you wanted.
NOTE: All used/reconditioned tanks will become very difficult to find within the year as the last major bottling plants are being disassembled in the US and Canada as I write this. The final used tanks are being rounded up and sold almost as fast as they hit the market. The last ball locks from the Pepsi plants were sold in 2009. Rumors abound about stashes here and there, but most are just rumors. We just received 1,100 tanks a week ago and all were pin locks.
Let’s be honest, we’re creatures of habit, change is not easy. If we started with Pin Locks and had become used to them, perhaps changing to Ball Locks would be annoying. Ball Locks can be connected wrong if forced on and are really hard to un-jam, sometimes even ruining the disconnect or the post. The surprise of a ball lock not locked, is an unpleasant event. Replacing costly manual relief valves might be upsetting. Either way we would have been comfortable with pin locks and like now finding the change hard to accept. Looking at Pin locks, you can see the obvious; no manual relief valves, and no way to accidently connect to the wrong side. With the gas side having 2 pins and the liquid side being three, it makes such and event impossible. Even the cost of disconnects and replacement relief valves are less. Pin locks are not more prone to leak, lose pressure or need repairs than ball lock. The opening on both style tanks is identical, so lids can be interchanged on most tanks.
#2 the ease of releasing pressure from manually operated relief valves. Observations over the years show that manual relief valves are replaced at a higher rate than non-manual reliefs in Coke tanks due to common mistake of leaving manual reliefs in the open position when tanks were empty. This causes the spring to be in the maximum compressed position for extended periods, which in turn also causes the amount of tension that holds pressure when closed to become less over time, resulting in pressure loss.
One new item I have tested is a conversion kit that turns a pin lock tank into ball lock tank. This kit has tank plugs made of anodized aluminum, universal poppet’s and new O-rings for the plugs and dip tubes. The kit costs more than the disconnects and has limitations. It only converts FIRESTONE tanks and due to the aluminum plugs material, requires you to remove before using an alkaline cleaner. Being a softer metal and depending on how often you sanitize, removing and replacing the plugs will cause thread wear. Also found the claim of working on firestone tanks does not apparently mean all FIRESTONE models, as I tried the kit on several and found the poppet valve was unable to open correctly and would not allow us to pressurize the tank. I found that the tall poppets out of original pin lock tank plugs fit perfectly inside the aluminum plugs from the kit and was able to connect and pressurize the tank as planned. For those of you familiar with a well-written article explaining the differences in tank styles, thread sizes and fittings by Mike Dixon, http://www.dresselbrew.com/Keg_Info.htm
, the type D poppet valve shown in the article was the winner in making the kit work. I will note that there are two types of FIRESTONE tanks, a model “A” and model “R”. The specific model was not mentioned in the information I found.
Can tank plugs from ball lock kegs be used to convert pin lock tanks? YES, but with limitations. Knowing and recognizing tank plug types and thread sizes makes this possible on some, but not all models. Most buyers have heard of tanks nicknamed “RACE TRACK” tanks or lids. These were an early style taken out of service about 30 years ago. The lids and tanks are not interchangeable with any other tanks. The tank plugs and thread sizes were also unique to those tanks. As they are fairly rare to come across, I will not spend any further time with details. Another rarity is finding plastic lids and any tanks, another early design that was removed from service decades ago. If you have any, it's recommended to replace them as they become brittle and fracture over time.
Getting back to swapping tank plugs, you will find 3 main thread sizes, starting with the smallest, 9/16”-18, then 19/32”-18 and the larger 5/8”-18. On the gas side you could find corresponding thread sizes in ball & pin lock plugs, but on the liquid side you will only find two ball lock sizes of 19/32”-18 & 5/8”-18. No 9/16” ball lock liquid plug was offered by the original manufactures. This eliminates the FIRESTONE A, FIRESTONE R, JOHN WOOD RA AND JOHN WOOD RC, pin lock tanks which had 9/16”-18 threads on both sides. The only option would be one of the new conversion kits or stick with the original pin locks. There is truly no real reason not to keep the pin locks. You’ll never mistake the hookups or have a disconnect pop off when locked into position. On pin lock tanks with two thread sizes, you can easily find and change the plugs to ball lock if desired. There are no ill effects in doing so. As long as the thread sizes match and the O-rings & poppets are in good shape.
Recognizing the tank plug styles and sizes takes a little practice and experience. First thing to know if that all gas connections have a defining notch on the sides/edges, the easiest gas plug to identify has a 16 point base instead of 6 like a standard nut. From experience, all of the 16 point gas plugs are 19/32”-18 thread. An easy way to identify the 5/8”-18 size plugs is that on one of the smooth surfaces close to the base, you will be able to see very small letters stamped into the surface, usually with the name “Hansen” on them. These are all the 5/8”-18 thread plugs and are always a liquid plug. 9/16-18 plugs in ball locks were gas side only and just a quick look at the small size threads make them pretty easy to identify. A local hardware store will have 5/8”-18 and 9/16”-18 thread bolts, also called fine thread, to help when checking thread sizes. Don’t bother looking for a 19/32”-18 thread bolt as you’ll never find one. This size thread is totally exclusive to beverage tanks. Just mentioning that size at a hardware store, will bring strange, bewildered looks. All new AEB and Korean manufactured tanks have 19/32”-18 threads. which has become the international standard.
Tank dimensions can play a roll in your choice also. Most if not all ball lock tanks are 25” tall by 8.5” diameter. Pin Lock tanks have two basic sizes, 21” and 23”. The tall Coke tanks have raised letters in the metal sides, which make them easy to spot, the shorter tanks are helpful in situations where your wanting to stack inside a fridge. These tanks normally have a 9” diameter. All this comes into play when evaluating the space available in your cooler/fridge. Once these tanks have been cleaned sanitized, have good seals and your connectors are all set, you should have little to no problems with any style tanks for the foreseeable future. This should help you when your looking to purchase tanks and think that spending more than 20 bucks is too much. Now that there are no longer millions of these tanks sitting around for the taking, you may wish to find the best you can and as soon as you can. Once the supply dries up, you can plan on roughly 100 to 150 for new tanks, considering, none are manufactured in this country any longer. Your paying for importing, and all the import duties, fees, taxes, shipping and other regulated fees that add to the cost. Cornelius, Spartanburg, Sharpsville and others all farmed out the manufacturing overseas years ago, and there are no plans to bring production back to the states anytime soon. Firestone Alloy, became Spartanburg, who contract built the tanks for Cornelius, then sold out to become Sharpsville, which contracted all the tanks to be made in Europe by AEB. Our company has purchased the Korean tanks and they were extremely well made. The quality was top notch, but the logistics of buying directly was challenging.
As of this weeks emails and discussions with all major bottling plant dismantlers in the US & Canada, there are no know beverage plants with used ball lock tanks available This has been known by resellers since late 2009. Pepsi & general beverage distributors have ceased all ball lock tank use. The only newly released batches of used tanks will be Pin Locks, with the supply of used tanks estimated gone within 12 to 24 months.