Long Term Storage Procedures – Storage In Excess Of 1 Month
Long-term storage procedures are used to prevent damage to and preserve the operational capabilities of dust collection equipment that cannot be immediately installed when received at the job site.
Generally, fabrication and shipment of equipment should be matched to the jobsite readiness so that it can be installed straightaway. But if it this is impossible and it becomes necessary to keep equipment on site for more than one month, it should be protected per the following procedures.
1. Cover unprotected openings
Dust collectors will be shipped to the jobsite with plenums fully gasketed and fastened together to the fullest extent possible. Generally, openings will be covered with plywood, plastic, or plugs. All of these coverings should be left intact if the unit is being moved to storage.
If equipment is to be stored, any unprotected openings should be plugged or covered to keep rain, snow, and other moisture from entering the housing. This can be accomplished with plastic wrap, plastic plugs, or wooden coverings, depending on how large the opening is.
2. Store equipment in a controlled environment
If possible, collector housings, auxiliary components, and parts should be stored indoors in a temperature and humidity controlled environment. For extended storage (longer than one month), place sorbent packs in any electrical enclosures to prevent humid air from damaging electrical components.
If sufficient indoor storage for all equipment is not available, collector parts, bags, cages, etc. should be stored indoors or in dry, totally enclosed trailers or sheds. Collector housings and larger components may be stored outdoors in a weather protected shed or off the ground on appropriate shoring and fully protected with tarpaulin or heavy plastic weather coverings.
3. Cover paint-protected equipment
Structural steel supports, framing enclosure steel, hand railings, and platform sections will be shipped in individual component pieces as described on the bill of materials for the unit. All steel will be painted in accordance with the contract specifications. The paint will provide adequate surface protection for a period of time.
As a general rule, all equipment is finish painted so it possesses “long-term” weather protection for the metal. However, materials such as support steel are generally stored laying on their side and rain/snow/dirt can pool on the horizontal surfaces. These pools can hasten potential corrosion, especially since contact between surface and moisture is prolonged.
If prolonged storage is necessary, the support and access steel should be stored carefully and protected by weather covering, especially during changes in seasons or during severe inclement weather.
4. Remember to inspect periodically
All equipment stored outdoors should be inspected periodically to monitor the integrity of the weather cover and the condition of the painted surfaces. Any rips or tears in coverings should be immediately repaired.
Any areas on the collector, auxiliary equipment, or support steel members where water or debris are collecting should be propped up to reduce the probability of future problems. These areas can be propped up with wood, other steel members, etc. Think of a camping tent and affix a center pole or cross members to keep rain from pooling on top where it could eventually leak to the inside.
5. Special care for accessories
- Rotary airlock valves
Remember, interior surfaces of rotary valves are not coated. Prior to storage, spray the interior of the valve with anti-rust preservative oil. Also, provide and install metal covers for the inlet and outlet flanges with at least four cap screws in each flange. Keep these covers on until you are ready to use the valves for service.
Next, completely fill the worm gear speed reducers with oil and replace the vented fill plug with a solid plug. Be sure to retain the vented plug for future operation. Then, read and follow the motor, speed reducer, and other equipment manufacturer’s instructions for long-term storage.
After completing the above steps, plug all conduit box openings on the motors and switches and store the valves off the floor in a dry, adequately ventilated, indoor area without extreme temperature changes. Turn the rotor a couple of revolutions every six months and leave the rotor in a different angular position after each turning.
- Screw conveyors
Interior surfaces of screw conveyors are generally not coated. Prior to storage, spray the interior of the trough and screw with the same anti-rust preservative oil you used on the rotary airlock valves. And again, provide and install metal or wood covers for the inlet and outlet flanges. Make sure the covers are properly secured to provide adequate protection for the internal components.
Completely fill the worm gear speed reducers with oil and replace the vented fill plug with a solid plug. Retain the vented plug for future operation. Then, read and follow the motor, speed reducer, and other equipment manufacturer’s instructions for long-term storage.
Finally, plug all conduit box openings on motors and switches and store the screw conveyors off the floor in a dry, adequately ventilated, indoor area without extreme temperature changes. Turn the flighting a couple of revolutions every six months and leave it in a different angular position after each turning.
- Exhaust Fans
Because it’s important that stored fans are protected from dirt and moisture, use a tarp or other weather tight covering for protection. Take care to avoid the use of black plastic tarps that may promote condensation on the equipment.
Bearings should be purged monthly with new grease to remove condensation and the fan wheel should be rotated by hand at least once every two weeks. This prevents bearings from “setting” and redistributes the bearing components.
Fans must also be isolated from any nearby vibration. High overall vibration levels can prematurely damage the fan and motor bearings.
When you are ready to use the equipment, purge the bearings with new grease before startup. Perform this procedure to operating level according to the bearing manufacturers’ specifications.
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