TAPPI (Technical Association of the Pulp and Paper Industry) provides guidelines for inspection and nondestructive testing of paper machine dryers in TAPPI TIP 0402-16.  While this document provides a thorough outline of the inspection process for dryer vessels, it isn’t particularly detailed regarding the inspection process of the ancillary dryer drainage equipment. In addition, there is significant variation in the depth of inspection and service that is provided by inspection service providers. Some examples of variation may include;

• Responsibility for the opening, cooling, cleaning, and closing of the manways
• Level of inspection of the dryer drainage equipment such as rotary joints, syphons, and spoiler bars
• Evaluation of the remaining life on rotary joint seals
• Ability to provide required repairs of dryer drainage equipment

Following the TAPPI guidelines is important, but this is only a start. Being well versed in the dryer drainage equipment provides capability that can be built into the inspection process. Being able to evaluate maintenance needs of this equipment can help identify the need for repair at the best possible time; when the machine is down, cool, and available for repairs. This can help ensure repairs are made before a catastrophic failure leads to valving out and possibly damage to a dryer. Beyond being certified to perform the inspection service and following paper mills’ specific inspection requirements, additional questions you can ask potential service providers include;

• Will you be opening, cooling, cleaning, and closing the manways?
• Are you familiar with this paper machine’s dryer drainage equipment, including rotary joints, syphons, and spoiler bars?
• Are you capable of and prepared for making any required repairs during this inspection process?

If the answer to any of these questions is no, there is likely a more efficient approach to your inspection process.