Dealing with high forces, metal in motion, hot parts?

The processes used to form and fabricate metals involve myriad hazards—complex machines, moving parts, substantial forces, and hot surfaces. The risks are many, so it takes a focused and continuous effort to enhance safety and reduce the frequency and severity of work-related injuries. The most recent Extrusion, Drawing, and Tube Reducing (EDTR) Roundtable conference, held Sept. 18-20 in Wilmington, N.C., and organized by the Tube & Pipe Association International®, focused on best practices for operating metal forming equipment in a safe and productive manner.

Although the subject matter was specific to EDTR processes, the conference had important lessons for any company involved in forming or fabricating metals. The outcome of the conference is a list of suggested practices that apply to any aspect of manufacturing: installing, operating, and maintaining equipment.

Planning an Equipment Installation

Safety doesn’t start when you power up the equipment. It doesn’t start when a piece of equipment is delivered. It starts when you plan to purchase and install a piece of equipment. An early focus on safety can make an installation go smoother and save time down the road.

Recommended practices:

• Whether the new machine’s power source is electric, pneumatic, or hydraulic, or some combination of these, locating the lockouts at a central panel makes everyone’s job easier when it’s time for maintenance.
• Review relevant requirements, guidelines, and standards, such as:
• • National Fire Protection Association (NFPA) 70E, Standard for Electrical Safety in the Workplace®.
  • NFPA 79, Electrical Standard for Industrial Machinery.
  • OSHA 1910.147—The Control of Hazardous Energy (Lockout/Tagout).
• Work with a safety products supplier to learn about the latest products; develop a comprehensive system of barriers, detectors, light curtains, and other products.
• Plan the locations of electrical cables, hydraulic lines, and pneumatic lines so they don’t present tripping hazards.
• Where practical, install video cameras that feed a monitor near the operator’s console so he can keep an eye on the area around his machine and ancillary equipment.
• If the new equipment or process requires any hazardous chemicals, verify whether any inert or benign chemicals can do the same job. Either way, plan for the necessary storage (and convenient placement) of the inventory. Inform the local fire department about the types and quantities of chemicals stored on-site.
• Take a look around. Has your housekeeping in the rest of the plant deteriorated? Now is as good a time as any to blitz each work area and get all tools and supplies back in good order. Sprucing up the entire place will make the next step easier.
• Task the equipment operators and maintenance personnel with incorporating site-specific safety procedures into the operating procedures.
• Before putting the equipment into operation, verify how quickly the emergency stops bring the equipment to a stop.
• Don’t close the procedure book after one or two good runs. Review the safety procedures for every process on every machine periodically.

Daily Operations

Many of the hazards in a manufacturing facility aren’t specific to a particular machine or process, but are present throughout the facility.

Slips, Trips, and Falls. Slip, trip, and fall hazards can be present nearly anywhere in any facility, so this is a good place to start.

Recommended practices:

• If cables and piping run near walkways, build channels to hold them, and paint the channels a suitable color such as safety yellow.
• Another way to get cables and piping systems out of the way is to cut channels into the concrete and move the hazards into the channels (below grade).
• If moving the hazards isn’t practical, improve the lighting to make hazards more visible, and paint the hazards lighter colors.
• In areas where hydraulic fluid or other oils are present, apply an antiskid coating to the floors to help to reduce slips.
• Fix oil leaks. Use permanent solutions, not temporary fixes. For example, where possible replace welded fittings with cast fittings.
• Transfer ownership of each work area to the employees.

Hands Off! Purchasing no-touch tools, installing specialized equipment, and developing procedures to prevent employees from making contact with machines and workpieces are key steps in preventing pinch, crush, and burn hazards.

Recommended practices:

• Use no-touch tools and procedures. Operators unfamiliar with aluminum sometimes learn the hard way that, unlike steel, aluminum doesn’t change color when it is hot. Hot steel’s characteristic red color is a clear warning not to touch it, but aluminum doesn’t provide such a warning. In some cases, gloves aren’t enough; no-touch tools eliminate direct contact with all parts, regardless of part temperature.
• Flipping a circuit breaker by hand at home is OK, but flipping a breaker in an industrial setting can cause an arc flash. In many cases, you must use an insulated pole (commonly called a hot stick) to prevent shock or electrocution and personal protective equipment to prevent burns from the arc flash.
• Try automation. Sometime, auto-mating a process might be the best way to go. For example, manually lubricating an extrusion mandrel requires you to enter the press pit. This means you must work close to the machinery. The press shouldn’t be powered up at this point, but a leaky hydraulic valve would allow the ram to creep forward even though it should be stationary. Some companies have put an end to manual mandrel lubrication. In addition to keeping the operator out of the pit, an automatic lubrication system, if designed well, can improve part quality because it applies the lubricant evenly across the mandrel’s surface.

Solitary Confinement. In no case should anyone enter a confined space without using the buddy system. A slip could lead to a fall that could render the person unconscious.

Figure: In most pipe and tube manufacturing facilities, hard hats, safety glasses, and ear protection are required for anyone working on the shop floor. For these packers, the shipping crate is elevated for ergonomic reasons. Photo courtesy of Haynes International.

Recommended practices:

• Maintain visual or voice contact with the person in the confined space to ensure that help is available.
• When working in an extremely confined area, monitor the oxygen level. Exit the area before it gets hazardously low.

Pickling Steel. Removing surface tarnish and mill scale is usually necessary before working the tube or pipe. One of the most commonly used steel pickling agents, hydrochloric acid, is hazardous to people and equipment.

Recommended practices:

• The most direct route to removing all of the hazards associated with storing and using corrosive agents is to eliminate them. Negotiating with steel suppliers for materials with better surface conditions can minimize the need for pickling on-site.
• If eliminating acid use isn’t possible, you might be able to mitigate some of the risk by switching to a corrosion-resistant plastic piping system and components.
• Inspect the components as frequently as necessary, watching for corroded lines.
• Install covers around flanges with color indicators.
• Install a secondary containment system to contain the acid if a leak were to develop.

Hindering Hydraulic Hazards, Locking up Lubricant Liabilities

The most obvious problem caused by a hydraulic leak is a loss of hydraulic pressure, but it can be much worse. Depending on the situation, a leak can lead to a fire. An example is a ruptured hydraulic line allowing the fluid to spew onto a hot extrusion. Be aware that fire-resistant hydraulic fluid (FRHF) oil is fire-resistant, not fireproof.

Recommended practices:

• Switch to a synthetic hy- draulic fluid for greater fire resistance. Be aware, however, that this might require changing the seals in the hydraulic circuit if they aren’t compatible with synthetics.
• If possible, install a bulkhead or other suitable barrier between the hydraulic equipment and the exit end of the extrusion press to prevent any oil from contacting the hot extrusion.
• Visually check hydraulic hoses often. A bulging hose is a sure sign of an impending failure.
• Depending on machine speed and temperature, the lubricant can become an airborne hazard. The lubricating oil can become a suspended mist that pollutes the work environment.
• Regardless of the specific type of chemical, the Material Safety Data Sheet isn’t your only guide to safe handling and use. If you have specific questions, contact the supplier directly.

Maintenance

Nearly everyone is familiar with lockout/tagout procedures. After cutting off the power source, whether it’s electrical, mechanical, hydraulic, pneumatic, chemical, thermal, or some other type, put a lock on the actuator (switch, lever, valve, and so on) so power can’t be applied. If it can’t be locked out, put a tag on it so other personnel know not to energize the equipment.

Recommended practices:

• Be aware that hydraulic accumulators store hydraulic energy and shutting off the hydraulic system doesn’t drain the fluid from the accumulators. It’s important to depressurize every component in the system. The same guideline applies to pneumatic systems.
• Replace the conventional “lockout/tagout” concept with “Lock it out, tag it out, try it out.” After locking down the switch, lever, valve, or other actuator, try to energize the machinery to be sure the hazardous energy is really dissipated.

Searching for Safety Schooling

Several associations, organizations, and government agencies provide hazard and injury prevention information and programs.

• General hazards

www.cdc.gov/niosh (see Hazards & Exposures)

www.osha.gov/dte/outreach/construction_generalindustry/gi_outreach_tp.hml

Figure: In addition to hard hats, hearing protection, and safety glasses, workers wear nitrile gloves, Kevlar® sleeves, and metatarsal steel-toed shoes to protect against a mishap when using a vacuum lift. Photo courtesy of Haynes International.

• Machine safety

www.cdc.gov/niosh/topics/machine

www.fmanet.org/training/programs-events.cfm

• Chemical safety

www.cdc.gov/niosh/topics/chemical.html

• Fire prevention

www.osha.gov (see OSHA 1910.39, Fire Prevention Plans)

www.nfpa.org