Hector Villareal, Weldcoa Inc.,
Edited by Ron Lucas, managing editor

Automated fill systems equipped with touch screens allow operators to pick a recipe from a menu for faster accurate fills

A palletized linear fill plant for oxygen. Moving cylinders on pallets within a fill plant minimizes handling and increases cylinder throughput.

Quick connects and valve guards greatly accelerate and simplify filling.

Develop a strategy before purchasing and installing new equipment.

Once a distributor is palletized, they can move cylinders around the plant with greater efficiency and maximize storage capacity with pallet racks.

An actuated valve package with electro-mechanical flow control valve. Pump controls provide more accurate fill rates and increase the service life of the cryogenic pump.

Whenever a distributor can deliver products faster and more efficiently it keeps customers happy, makes the distributor more profitable and differentiates itself from the competition. Upgrading filling technologies can accomplish that, but the key to a successful implementation lies in understanding how individual components complement and enhance the process as a whole. Let's take a look.

Distributors first need to develop an overall upgrade strategy before purchasing and installing new equipment.

A plan might involve some, or all, of the latest in available filling technologies. The entire upgrade could be accomplished at once, or phased in as older equipment becomes obsolete and is replaced.

Step back and review the operation
Since each distributor has a unique product mix there is no "one size fits all" solution. So a review of the plant's needs begins with an overview of the gas mixes and volumes filled at the plant and an examination of the firm's delivery and filling costs. Then, based on that analysis, appropriate technologies can be selected and a purchasing and installation timetable can be established to deliver the maximum impact to the bottom line.

The types of filling technologies distributors could consider include external and internal palletization; palletized filling; automated filling process; and adopting efficiency enhancing devices such as air tools, quick connects, valve guards and residual gas valves.

External palletization
To illustrate benefits of palletization for external deliveries lets compare two distributors loading 40-foot delivery trailers. Distributor A operates manually, rolling individual cylinders onto the truck. Distributor B palletized its external delivery.

Distributor A has two men working 2 hours to unload the empties, and another 2 hours to loads filled cylinders. Distributor B, however, unloads and reloads in 25 minutes using one person and a fork lift.

Although the obvious primary benefit is a quicker delivery with less manpower, Distributor B leverages additional benefits that are less obvious. First, its time savings allows it to operate with a smaller fleet — trimming maintenance costs, insurance premiums, and driver-related costs.

Distributor B also can prep palletized loads for branch locations before delivery trucks arrive, increasing the speed of shipment to branch locations.

Some distributors who have avoided palletization use a "drop and swap" method to speed up the exchange. They load an entire trailer before the driver arrives and swap that loaded trailer for an empty one. These distributors understand the benefits of prepping the load, but still incur costs associated with extra trailers.

Internal palletization
Moving cylinders on pallets within a fill plant minimizes handling and travel, decreases the use of manpower, and increases cylinder throughput. In addition, moving cylinders strapped to a pallet minimizes the opportunity for repetitive motion injuries and creates a safer, more manageable inventory as opposed to clustering them on the shop floor.

Palletized fillling
Once a distributorship has full capability to move cylinders on pallets, the next logical step is switching from linear to palletized filling.

Aside from investing and installing new technology, this step also requires adopting a new mindset among operators in the plant. In traditional linear filling, the worker performing the fill operation also inspects and sorts the cylinders. On the other hand in palletized fill plants, the sorting and inspection is performed on a sort pad by a another operator — the sorter/inspector.

This method allows the filler to dedicate his entire time to filling cylinders as they arrive on the fill island. Since palletized cylinders are brought to the fill island 18 at a time the speed and efficiency acquired more than offsets the cost of the additional worker. The filler, however, now must trust the sorter/inspector to inspect the cylinders properly.

Distributors cope with this in one of three ways. Some choose to have the sorter/inspector and the filler change jobs from time to time to establish trust. Others create recordable check lists and criteria. A third method is to convert the fill island into a combination sort/inspect/fill station. Owners must choose a course based on their individual situation.

There are two basic fill island configurations — two sided and one sided. Twosided islands offer the maximum flexibility. The onesided island is chosen where plant space is constrained.

Automated cylinder filling
Automation is best applied to high volume repetitive processes. Automation frees operator's time so that more functions can be performed during the same work hours while managing output. Automated cylinder filling increases productivity, guarantees uniform quality fills, and creates a safer work environment. Additionally, some models such as Weldcoa's use a touch screen programmable logic control platform that prompts users through the process and streamlines operator training.

Global gas suppliers have automated their high volume fill processes for years. Within the last eight years, the cost of the technology has become affordable for mid-size to large independents.

Automation can be adopted in stages for both traditional, linear fill plants and palletized facilities.

• Simple semi-automation: At this level, the equipment automatically starts and stops the fill pump.
• Advanced semi-automation: This level is intended for straight gas filling. The equipment controls the full vent/vacuum/filling process.
• Full Automation package: At this level, the equipment controls the full vent/vacuum/filling process and retains and collects data including the distributor's gas recipes, fill curves, safety parameters and fill records. All the data from each fill is available for download to a PC and can be used in reports and spreadsheets, or emailed to a remote location or printed.
• Pump Controls: These controls eliminate the need for ground tubes, saving dollars on equipment. They allow operators to run cryogenic pumps at a low RPM and a high pump discharge pressure. This provides more accurate control of the fill rate at the pump, and increase the life of the cryogenic pump itself by continually monitoring the pump's status including its output voltage, output current and output hertz.

These systems also feature alarms that shut the system down to safe guard the pump motor if monitors detect excessive pressure or cavitations.

Finally, the pump's control system can switch the pump's capacity between multiple operators throughout the facility for more flexible operation.

Techno-time savers
A number of advanced fill plant devices save time, boost efficiency, lower operating cost and work equally well in a both palletized and linear fill plants.

Valve Quick Connects allow operators to rapidly connect and disconnect the fill-lead-to-the-cylinder valve saving operator time and money while diminishing the risk of repetitive motion injuries.

Air tools open and close cylinder valves more quickly and efficiently than manual tools. They also save time and money, and reduce repetitive motion. Operators, however, must take care not to over torque cylinder valves, and managers must regularly inspect settings on the air tools to insure that valves are not damaged.

Valve Guards eliminate the time lost during the fill cycle spent unscrewing and re-screwing cylinder caps. Valve guards last as long as cylinders, and are replaced only when damaged. Valve guards protect cylinder valves during filling, operation, storage and transport, and reduce repetitive motion while saving time and money. Europeans adopted them 20 years ago.

There are many types of valve guards on the market today, so distributors should ensure that the one they select will accept quick connects, air tools, regulators or other equipment used in the plant.

Residual Gas Valves prevent moisture or gas from backing into the valve. During filling, they eliminate the vacuum stage of the process eliminating a step in the process. Residual gas valves also make "top filling" possible. Top filling allows the residual gas in a cylinder to be re-sold instead of vented off.

Residual gas valves have been in existence for years, but their cost only recently has fallen making them economic for distributors.

As consolidation during the last 5 years has narrowed the field, more independents than ever are filling their own industrial, medical, liquid and specialty gases. Opting to upgrade existing fill technologies can help a distributorship improve efficiency, lower costs and differentiate itself in an increasingly competitive market.

About the Author
Hector Villarreal is Director of Marketing Sales for Weldcoa Inc., For more information call (708) 531-1200 or visit weldcoa.com