Fire Department Connection
One of the most common FDCs, known as a Siamese or two-way connection, has two 2 1/2-inch female swivel connections. NFPA requires that all fire department connections use 2 1/2" National Hose (NH) threaded female couplings unless the authority having jurisdiction designates another specific connection type.
In buildings constructed after 1993, NFPA 14 requires standpipe outlets to flow a minimum of 250 gpm at, as mentioned previously, a minimum pressure of 100 PSI.
Some older buildings only have standpipe systems while many newer buildings will have a combination system, which supplies the fire sprinkler system and the standpipe system. Standpipe systems are designed to provide fire protection water for hose lines in strategically placed locations inside a building or structure.
All pumpers will pump their capacity at 150 psi at the pump, so increase the throttle slowly until your discharge pressure is at 150 psi while being careful not to run away from your water supply. If your pumper is equipped with a multi stage pump, place the pump in the volume stage.
A solid stream nozzle is generally the most useful for exterior fire attack. The solid stream will deliver the greatest amount of water over the farthest distance. It can also be directed through an opening at the compartment lining to cause the stream to disperse into small drops and absorb more heat.
Use fog if needed as you move closer. If it is an engine or rear compartment fire, the first attack team should attack the fire 45 degrees at an angle toward the front or rear of the vehicle. Firefighters should not get themselves in a position in front of a 50 pound bumper that can explode outward around 200 feet.
The check valve will help your water system maintain pressure when the pump shuts off and also prevent backspin, upthrust, and water hammer. It is recommended that at least one check be installed in all submersible well pump installations. Many well pumps have built-in check valves.
Check valves are found everywhere, including the home. If you have a sump pump in the basement, a check valve is probably in the discharge line of the pump. Outside the home, they are found in virtually every industry where a pump is located.
A check valve will be used commonly on the discharge of the pump to prevent backflow from the downstream system, when the pump shuts off. Check valves are used to prevent contaminated media in branches from flowing back into the main trunk line.
Simply put, a check valve allows flow in one direction and automatically prevents back flow (reverse flow) when fluid in the line reverses direction. They are one of the few self-automated valves that do not require assistance to open and close.
The bodies (external shells) of most check valves are made of plastic or metal. An important concept in check valves is the cracking pressure which is the minimum differential upstream pressure between inlet and outlet at which the valve will operate.
A non-return valve allows the flow of fluid in only one direction. A check valve also allows flow in one direction and automatically prevents backflow when fluid in the line reverses direction. Typically the check valves are designed for a specific cracking pressure.
An arrow or the symbol for any type of check valve (a fluidic/pneumatic logic symbol) on the outside of the body indicates flow direction. In this image, flow is from top to bottom. Some check valves will have both the logic symbol and an arrow to indicate correct orientation.
Check valve can be installed in horizontal or vertical piping runs, with the flow running upward.
Hydraulic valves are subdivided into three main categories: directional control valves, pressure control valves and flow control valves. All valves operate a different function in the hydraulic system.
Check valves are used in many applications but we will focus on what we use in irrigation. No human intervention is required for the check valve to do its job, it is operated by flow and differential pressure. Inline check valves are used anywhere you want to prevent water draining from the system after shutting down.
As a general rule, you should winterize your system at least a week before the first freeze is expected. Your grass will survive without regular watering during that time, as the plants are already preparing for the dry winter season.
They provide automatic flow control of liquids and gases using a variety of mechanisms. Small-bore low-pressure systems and vacuum systems make extensive use of diaphragm check valves. They are used to prevent reverse flow and the problems that could result from it.
The other reason may be water leaking through the zone valve (a check valve in the sprinkler will not fix this leak). The most common reason why water leaks through a valve is because there is debris obstructing the valves diaphragm.
Ball PVC Check Valves
A ball type PVC check valve operates by restricting the flow of water in one direction using a floating ball that will block the valve. When water flows the desired direction the ball is pushed away from the valve opening.Simply put, a check valve allows flow in one direction and automatically prevents back flow (reverse flow) when fluid in the line reverses direction. Unlike other valves, they continue to work even if the plant facility loses air, electricity, or the human being that might manually cycle them.
There are two reasons why a sprinkler will leak water when the system is supposed to be off. The most common reason is called “Low Head Drainage”. If it is low head drainage, residual water will stop flowing after all the water has left the pipe.
FBC
| Acronym | Definition |
|---|
| FBC | Facebook Chat |
| FBC | Full Blown Chaos (band) |
| FBC | Food Beverage Canada |
| FBC | Fully Buzzword Compliant |
2 requires a 4" pipe size for fire engine connections. Exception #2 allows a single-outlet FDC where piped to a 3" or smaller riser. These criteria indicate that unless the riser of the sprinkler system is 3" or smaller, the FDC must have a minimum of two connections.
automatic fire sprinkler system
