A bird screen, also known as a trash guard or bird guard, is a device installed on piping and equipment to prevent birds, debris, and other objects from entering openings and causing damage. Bird screens are commonly used in industrial facilities, power plants, oil refineries, LNG terminals, chemical plants, and other sites with extensive piping networks and equipment.
Why are bird screens used on piping and equipment?
Bird screens serve several important functions:
- Prevent bird nesting and roosting – Birds like pigeons can build nests and roost inside pipes, vents, and equipment openings. This causes blockages, corrosion, equipment failure, and unsanitary conditions.
- Keep out trash, leaves, dirt – Screens stop windblown debris from accumulating inside equipment and potentially causing damage or fires.
- Improve personnel safety – By keeping equipment free of bird droppings and nesting materials, bird screens help reduce health hazards to workers.
- Prevent interference with equipment operation – Birds or their nests can interfere with valves, instruments, and other devices, preventing proper operation.
- Protect product quality – In facilities like food plants, bird screens prevent contamination of products by birds, droppings, feathers, etc.
In summary, bird screens are a simple but vital safeguard to keep piping and equipment functioning properly while protecting personnel, products, and operations from bird-related hazards.
What types of openings are screened on piping and equipment?
Bird screens are often installed on these types of openings:
- Pipe vents and drains – Prevent birds from nesting inside pipes.
- Instrument taps and connections – Keep birds from interfering with flow, pressure, level, temp sensors.
- Pump seal housings – Protect seals from debris and nesting.
- Valve stems – Keep stem areas clean for proper valve operation.
- Equipment vents – Block birds from roof vents, cabinet vents, etc.
- Motor fan inlets – Prevent nest debris from entering motor air intakes.
- Stack and chimney outlets – Keep birds out of stacks.
- Roof manways, hatches – Screen off roof openings into vessels and equipment.
- Structural I-beams – Deter nesting on beams in equipment structures.
The exact locations requiring bird screens depend on the piping configuration, equipment design, and plant-specific conditions at each facility. Plant engineers conduct a survey to identify areas needing screening.
What materials are used to construct bird screens?
Bird screen materials include:
- Wire mesh – The most common material. Made from stainless steel or galvanized steel wire formed into a mesh grid. Durable, long-lasting, and available in various sizes.
- Perforated metal – Metal sheet with small holes punched throughout. Often made of aluminum or stainless steel. Provides smooth surface.
- Expanded metal – Metal formed into a lattice-like pattern with openings. Used where high airflow is needed.
- Bar grating – Grating made of metal bars spaced apart. Used when heavy objects may impact screen.
- Polymer sheets – Plastic sheets with holes drilled in a pattern. Lightweight option but less durable than metal.
The screen material is selected based on application requirements like strength, corrosion resistance, flame resistance, cost, and airflow needs. Stainless steel wire mesh is commonly used for its excellent durability in industrial environments.
What are the key design factors for bird screens?
Bird screen design considers these key factors:
- Openings size – Holes must be small enough to block birds and debris but large enough to allow airflow and drainage.
- Location – Screens must provide coverage on all openings birds can access but allow maintenance access.
- Attachment method – Screens are attached securely to prevent detachment from vibration, pressure, or nest materials.
- Durability – Screens must withstand weather, corrosion, UV exposure, nest materials, and periodic cleaning.
- Flame resistance – Screens may need to be fire-resistant in combustion areas.
Industry standards like the EEMUA Publication 147 recommend openings no larger than 20 mm x 20 mm to exclude common pest birds. High-pressure steam vents may require slit openings rather than mesh for proper airflow. Proper design ensures screens serve their function without restricting flows or operations.
How are bird screens installed on piping and equipment?
Proper installation methods are key to effective, long-lasting bird screens. Here are some common installation techniques:
- Weld mesh screen to steel fabrications that surround an opening.
- Clamp screens between flanges with gaskets using bolts.
- Place screen inside pipe flanges using compression fit hardware.
- Use strips, bands, or tie wire to attach screen to irregular shapes.
- Attach screen to equipment with brackets, straps, or fasteners.
- Adhere screen to equipment using high-strength epoxy or adhesives.
Bird screen frames may be prefabricated to fit standard pipe sizes and flange configurations for easier installation. Proper tools like welders and metal shears may be needed to custom-fabricate screens for unique applications.
What maintenance is required for bird screens?
To remain effective, bird screens should be:
- Inspected – Check routinely for gaps, holes, detached screens. Inspect after major storms.
- Cleaned – Wash screens periodically to remove dirt, salt, bird droppings. Avoid nest build-up.
- Replaced – Fix or replace damaged screens. Replace deteriorated screens.
- Recording – Document screen conditions and maintenance activities.
Bird screens are first installed with openings aligned to allow drainage and airflow. Nest materials and debris over time can block the openings. Periodic washing with a pressure washer or manual scrubbing helps maintain proper screen function.
Conclusion
Installing well-designed bird screens on piping, vessels, equipment, and structural openings is an effective way to prevent operational, safety, health, and maintenance issues caused by pest birds in industrial facilities. With careful material selection, sizing, and installation methods, screens can provide years of trouble-free protection. Maintaining screens is essential to keep them working properly over the long term.