Inspect and test your safety controls to ensure safe oven operation.

The maximum solvents load and other data are stamped into the oven data plate mounted on the main control panel.

Safe, effective oven operation requires more than just hitting a switch. Regularly inspecting and testing your oven's safety controls should be a regular part of your oven safety procedures. And, of course, the first step in any maintenance process is to review and adhere to all safety and maintenance bulletins in your oven's maintenance manual. Here are 10 more tips to follow.

Any modifications or additions made to the oven should not interfere with the pressure-relief doors. These doors relieve pressure and help contain an explosion.

TIP 1: Don't Overload

Do not load the oven with more combustible solvents than what the oven was designed to handle. The maximum solvents load is stamped into the oven data plate mounted on the main control panel.

TIP 2: Purge, Purge, Purge and Purge Again

Be sure the oven purge time, prior to ignition, is at least as long as shown on the oven data plate. The minimum four to six volume air changes required for purge before shutoff should not be reduced by modifications or additions to the oven.

TIP 3: Don't Block Pressure-Relief Doors and Panels

Venting is critical in preventing injuries and reducing the amount of damage an oven sustains should an explosion occur. The oven enclosure should be able to withstand the rapid expansion of gases and allow the work openings, relief panels and doors to immediately relieve pressure. Neither modifications nor additions should be made to the oven that would interfere with the pressure-relief operation of doors, wall panels or roof panels. Also, be sure your operators know why it is important not stand in front of or block pressure-relief doors or loading doors during startup and operation of the oven.

In addition, oven doors that utilize pressure latches for pressure-relief style doors must be inspected and maintained according to the manufacturer's suggestion sheet.

TIP 4: Re-Evaluate When You Modify Equipment or Process

Modifications to existing oven equipment or any process change resulting in increased solvent introduction (such as increased coating weights, coating formulation changes or increased production) will require re-evaluation of the solvent introduction to the oven relative to compliance with the 25 percent (or less) lower explosive limit (LEL) concentration requirement of insurance underwriters and/or the NFPA 86 standard.

TIP 5: Avoid Production Pressure Pitfalls

Don't let production pressures convince you to bypass safety devices or neglect regular maintenance.

  • Do not jumper the electrical circuit of any safety devices. If a safety device is not functioning properly, find the cause and correct it.

  • On all gas- or oil-fired ovens, close the manual fuel cocks in the piping train whenever the burner is shut off.

  • Visually inspect combustion air filters, where applicable, and clean or replace on a regular basis.

TIP 6: Inspect and Clean Exhaust Fans Regularly

If applicable, the main exhaust damper that is mounted on the discharge of the exhaust fan must be inspected and cleaned on a regular basis -- at least once every six months -- to prevent condensate buildup and the resulting decrease in exhaust volume.

TIP 7: Stay Under the Limit

Do not exceed the maximum high temperature setting of the high temperature limiting device. This rating is posted on the oven data plate.

TIP 8: Be On Guard

When guards are removed for maintenance purposes, they must be properly reinstalled before starting up the equipment. To prevent bodily injury, it is the responsibility of the oven user to ensure that proper guarding of moving parts of the oven and product conveying system is present when the equipment is operated, to suit specific installation requirements and to comply with all local, state and national code requirements.

TIP 9: Stay in Compliance

If a permanent ladder, stairway or other permanent access means is ever installed that would allow personnel access to the top of the oven, then guardrails and other provisions may be required to comply with OSHA requirements.

TIP 10: Train, Train and Re-Train

Your oven should only be operated by knowledgeable personnel who have been trained in the operation and safety features of your particular oven. Consider periodically reviewing operating guidelines and safety equipment to be sure that your oven continues to operate safely. PH