Getting the SPA treatment

Using safety and performance audits to improve gas welding and fabricating

September 1, 2009

You may think your gas welding and fabrication operation is on track, but what you may not see could hurt you in the long run. Performing a safety and performance audit will help you evaluate the safety and efficiency of your operations, minimize liability, and help ensure compliance with local state fire and safety requirements.

Figure 1
A gas-saver flowmeter regulator can help minimize gas waste.

Appearance counts heavily when it comes to assessing a weld, but a lot more comes into play when you evaluate for strength and quality. Likewise, a job shop's gas welding and fabricating operation might appear to be on track, when in fact processes, safety, and efficiency should be causes for concern.

Audit Objectives

As its name suggests, a safety and performance audit (SPA) is designed to help you evaluate the safety and efficiency of your operations, as well as minimize liability and help ensure compliance with local and state fire and safety requirements. The best guideline to follow is the National Fire Protection Association (NFPA) standard for storage and handling of compressed-gas cylinders and the design and installation of oxyfuel gas systems. Understanding the standard is integral to a complete SPA and to upgrading and improving systems.

An SPA to assess welding and fabricating applications can help you achieve four main objectives:

1. Understand how processes are used.
2. Evaluate safety issues.
3. Analyze processes for cost and efficiency.
4. Recommend steps to improve safety and performance.

Processes and Efficiency

Putting together the documents for an SPA is not difficult. The audit is most effective when it's completed by a team of at least two people. Four eyes can see more than two, and it helps to have one person writing as the other points out issues.

Your team needs to assess every aspect of the workstation and how processes are performed, which can give you an opportunity for upgrades or improvements to achieve greater efficiency as new technologies come to the forefront. For instance, the assessment might reveal that changing from one mode to another takes too long, and perhaps you should consider a different welding method.

The overall objective to strive for with your systems and equipment is efficiency. When looking at your shop, consider this first: How can I make this process less costly to maximize return on investment?

To help ensure success, you'll first need to research and understand the requirements of the process or application; that way, you'll be able to recommend an effective product or change of product. If you need help, question suppliers. Turn to co-workers who have prior experience in these applications, and talk to the equipment manufacturer for recommendations.

Maintenance and Safety

The safety portion of the audit must be thoroughly detailed. It's human nature to become complacent over time, but when that happens with a potentially deadly process or equipment, the outcome can be disastrous. Weekly in-house preventive maintenance is recommended for all gas handling equipment. This inspection should include visual and bubble-spray leak checks on all connections before the system is used.

The importance of periodic inspection and documentation of all gas systems is illustrated by a situation that occurred many years ago. A distributor was quoting a switchover system to replace a customer's oxyacetylene manual manifold system, but the customer didn't want to replace the piping in the shop. The distributor and the customer agreed to check a leg of the shop's fuel gas piping by blowing it out with nitrogen. When the blowout was completed, there was so much fog in the shop that it was half an hour before anyone could see again.

They found that while the fuel gas piping system had the required liquid-filled flashback arrester installed, no one ever checked it or added any fluid to it. The fog in the shop consisted of year's worth of carbon soot buildup from all the burnbacks in the piping. The job shop was fortunate that no explosion or fire reached the acetylene cylinders.

SPA Checklist

Your welding shop's SPA should encompass the following:

1. Type of gas used—Know specifically what gas the application requires, and avoid assuming the last person did it correctly.
2. Purity level—Purity is critical in every application. Again, do not presume the last person recommended the correct gas product or purity level.
3. Maximum pressure required—Gas pressure is especially important with the fluctuating price of gas products as job shops look for ways to conserve.
4. Maximum flow required—If the flow requirement is high, a gas-saver flowmeter regulator, which manages gases more conservatively, can help reduce costs (see Figure 1).
5. Type of application—When determining an application's requirement for gas equipment, learn as much as you can about the process. Companies often use the same setups in one location as they do in others, but that isn't always appropriate. It depends how the initial process or delivery system was set up.
6. Product source—This information is essential for correctly and economically supplying the end requirement with enough pressure and flow.
7. Temperature—The operating temperature range of equipment is normally available from the product distributor or manufacturer.
8. Environment—Look at where the equipment is or will be installed and the seasonal climate it will be exposed to.
9. Monitoring—Determine if this is a critical function that has a costly or painful consequence if it fails, runs out of gas, or shuts down. Alarm systems can provide the solution.
10. Mounting—Correct installation is important to minimize the potential of death or personal injury.
11. Future requirements and expansion potential—Consider if there is potential for increased demands on the system in the future. Sizing it appropriately will allow you to grow into the system without having to remove and replace it later. For instance, switching from individual gas cylinders to a main manifold system with lines plumbed into work areas will decrease individual cylinder changeouts, allowing operators to meet increased production demands without dealing with cylinder maintenance.

In the final analysis, an SPA can be an effective tool to help you evaluate your shop's safety and efficiency, paving the way for system technology upgrades and improvements.