As we approach a shutdown used by many manufacturers to service plant equipment, it is important to ensure that impregnation systems and sealants be included in the shutdown maintenance program.
Scheduled plant shutdown periods are an excellent time to get caught up on the maintenance of factory equipment. It is also a time to make sure a vacuum impregnation system is properly prepared for extended idle time. The outline shown below is a guideline to ensure a vacuum impregnation system and its sealant will remain stable during shutdown and allow for quick and effective re-start.
Generally speaking, the following tasks apply to most impregnation systems:
- Verify that all process fixtures have been removed from the system.
- Close the main water supply valve(s). NOTE – if the sealant cooling system uses a chiller, ensure water flow to the chiller unit remains on.
- Turn heating elements for rinse and cure stations to OFF.
- Turn air supplying agitation systems OFF.
- Drain the rinse and cure modules and remove any mineral and sealant deposits from the tank, with special attention paid to cleaning the heating elements.
- Reclaim any sealant that has accumulated in the centrifuge and drip stations to the vessel or reservoir (depending on the system).
- For systems equipped with sealant refrigeration, verify system power to the condensing unit and control power to the temperature monitoring equipment remain ON.
- For systems using thermal-curing sealant, ensure the condensing unit is set to keep the sealant at or below 72F.
- For systems using anaerobic sealant
- Confirm the functionality of sealant aeration grid and backup air systems.
- Using stabilizer, adjust the gel time of the sealant to 120 minutes.
- Set the cooling system to keep the sealant at 55F.
- Continue to perform gel and viscosity tests on the sealant, no less than weekly.
- If the system is in a hot environment (> 85F) or may be idled for more than two (2) weeks.
- Transfer the sealant from the system to 250 gallon plastic totes, filtering it through a 5 micron filter. NOTE – using metal drums or other metal containers for anaerobic sealant is not advised as the metal may act to accelerate the sealant.
- Aerate the tote with 30 psig of clean, dry compressed air at a 15 scfm flow rate.
- Store the totes in a temperature controlled environment (at or below 72F) and out of direct sunlight.
While idled, mechanical components on the system that are directly exposed to sealant should be removed, inspected and cleaned or replaced as necessary. Examples include
- Locking ring rollers on pressure vessels
- Sealant transfer valve on DV and DVP systems
- Drop cylinder in DV systems (if so equipped)
- Sealant recovery valves
- Vessel and reservoir level sensors
- Vessel and reservoir temperature probes
- Vacuum pumps
- Vacuum resin traps
- Aeration grids
- Vacuum / pressure transducers
Of course, normal maintenance of the pneumatic, hydraulic and electrical systems should be performed as necessary.
An effective shutdown maintenance program can ensure that the impregnation system is a reliable asset in your manufacturing operation. These steps can ensure the effectiveness of your program. To discuss your specific system or situation, contact us at 330-562-1440 or send us an email.