Category Archives: Industrial Equipment and Machinery

Lockout-Tagout Process

In this article, I will discuss the basic processes for LOTO safety. Remember that these are ‘basic’ steps, common to all Lockout procedures, and you need to be more specific, according to your situation. These steps ensure that you have all the procedures in your safety program. Remember, the Occupational Safety and Health Administration (OSHA), requires most private sector entrepreneurs to have it. US Department of Labor agents also include several employers from the public sector.

Not only is a LOTO program imperative for the safety of your employees, it also means savings, since any scope of injury is greatly reduced.

Step 1: Understand the problem, identify the energy source and the equipment to be locked out. Prepare for shut down.

Step 2: Once energy to the machinery/ equipment has been shut off, notify all workers who are affected. Ensure that the shutdown is not going to pose a hazard to anyone.

Step 3: Shutdown the equipment. Ask the worker who normally performs the shutdown to do so by using established procedure. If you are working on a customer site, ask them to shut off instead. All the moving parts should come to a stop.

Step 4: Isolate the machinery from every energy source. The main energy-isolating device, like a master power switch has to be deactivated, for each source of energy. It’s required to get this done by a qualified professional. They need to be wearing PPE (Personal Protective Equipment), i.e. any helmets, goggles/eye protection, boots, etc. to protect them from injury.

Isolation techniques include opening electrical disconnects. One needs to stand to a side while opening electrical disconnects, to stay safe in the event of an electrical arc.

Step 5: Lockout/ tagout the machinery next by affixing personal, approved coloured locks to energy-isolating devices, for every energy source. Use tags. Master keys are not permitted for personal locks used for OSHA Safety Products. Each worker to have one key per lock. Unless you use a group lockbox, there should be one lock per worker, at every energy source. One is not permitted to lend or borrow either locks or keys.

Tags should always be accompanied by locks, unless the tags offer protection equivalent to a lock, or the machinery/ equipment can’t be locked out. Ensure that tags cannot be pulled off easily.

Step 6: Release any stored and residual energy.

Step 7: Try the equipment to verify that isolation of energy has taken place.

How to Use Slurry Pumps

The slurry pump is a heavier and stronger version of a centrifugal pump used to handle harsh or abrasive applications. Standard centrifugal pumps are used mainly to dissipate clear liquids, while slurry pumps are used for hydraulic solids transportation.

The term “Slurry Pump” refers to all of the devices used in the transport of solids. More specific names are given to them based on the size of the solid being transported or based upon its particular use.

The slurry pump is used to transport mud, clay, silt and sand in the size range of solids up to 2 millimeters. Sand and gravel pumps handle the transporting of shingle and gravel in the 2 to 8 millimeter range. Additionally, gravel pumps may transport solids up to 50 millimeters in size. Dredge pumps are used to handle solids up to and exceeding 50 millimeters.

Specific names are also based on the application or use. Froth pumps handle frothy slurries, mainly in flotation. Carbon transfer pumps provide the gentle hydraulic transportation of carbon in pulp and carbon in leach circuits. Sump pumps are mainly operating pumps from floor sumps that have submerged houses but dry bearings and drives. Submersible pumps, like the name implies, are fully submersed, including the housing and drive.

Depending upon the application, the slurry pump can be installed dry, semi-dry, or wet. Most horizontal slurry pumps are installed dry. In this case, the bearings and the drive are kept out of the slurry, and the wet end is closed. The slurry is free standing and clear of any of the liquids. The vertical tank may also be installed dry. This has an open sump with the pump casing mounted directly under the tank. The slurry is fed from the tank and expelled horizontally. No submerged bearings are required in this design.

Semi-dry installation is a special configuration for dredging operations. Horizontal pumps are used with wet ends and submerged pads. For this application, special sealing considerations must be made for flooded bearings. Wet installations are used when there is a need for a pump that is completely submerged. An example is removing slurry from a tub where there is a very volatile level of free slurry. In wet installations, both housing and drive are flooded, which require special design and sealing considerations.

When determining slurry pump design, the type of application is considered to ensure proper performance under a variety of conditions. They are designed to handle highly abrasive, abrasive, and mildly abrasive conditions.