Why are return bends needed for pendent sprinkler heads on a wet system?

The purpose of a return bend, also known as gooseneck, is to prevent the accumulation of sediment, mineral deposits, and pipe scale in the pipe drop to a fire sprinkler. If these materials collect, the drop pipe or sprinkler orifice could be obstructed and impaired.

What is a return bend in a sprinkler system?

A return bend is the piping arrangement for pendent sprinklers where piping stems from the top of the branch pipe (riser nipple), runs horizontally (arm over), and then down to the sprinkler (drop). Components of a return bend in a fire sprinkler system.

What is the purpose of earthquake bracing on a sprinkler system?

Seismic Bracing

Sway bracing is provided to prevent excessive movement of system piping. Shifting of large pipe because of an earthquake has led to the pull-out of hangers and the fracture of fittings. With some exceptions, seismic bracing is required at the following locations: Top of the system riser.

Can you bend fire sprinkler pipe?

PEX tubing must be protected from fire similarly to CPVC pipe. The tubing cannot be exposed and must have a layer of gypsum wallboard, plywood or lay-in ceiling tiles protecting the tubing. The PEX tubing is flexible and can be bent when installing the tubing. Fittings also can be used to make changes in direction.

What is a pendent sprinkler head?

What is a pendent sprinkler head? A pendent (sometimes spelled “pendant”) fire sprinkler hangs from above-ceiling pipes and distributes water in a domed or conical pattern using a convex deflector.

How fire sprinkler systems work (3D Animation)

What is the difference between an upright sprinkler head and a pendant sprinkler head?

Upright sprinklers are installed with deflectors above the sprinkler, while pendent sprinklers have deflectors below the sprinklers. Common industry practice is to use upright sprinklers in areas without finished ceilings and pendent sprinklers in areas with finished ceilings.

Where are pendent sprinklers used?

The pendent fire sprinkler head is the most common type and it's mainly used in offices, hotels and factories. It hangs down from the ceiling and sprays water in a circular motion in order to cover the most ground.

What is return bend?

Definition of return bend

: a bend (as in a pipe fitting) that alters the direction of its center line 180 degrees.

Can PVC pipe be used for fire sprinkler system?

Certain CPVC plastic pipe and fitting systems listed to system standard UL 1821 can be used to supply water to fire sprinklers for low-rise residential occupancies according to installation standard NFPA 13R and to supply light hazard occupancies according to NFPA 13.

Can you use galvanized pipe for fire sprinkler system?

Never use galvanized steel piping for wet pipe fire sprinkler systems. If galvanized steel piping is used for dry and preaction systems, then an FM Approved nitrogen generator must be used for pressure maintenance to prevent oxygen corrosion.

Where is seismic bracing required?

Conduits, including HVAC ductwork, piping, and electrical conduits and raceways, may also require seismic bracing. ASCE 7 says that: HVAC ductwork needs bracing when the duct has a cross-section 6 ft. or larger or when it weighs more than 17 pounds per linear foot, or when it has an I_p=1.5.

Which components are designed to protect sprinkler pipe against lateral and horizontal movement?

Seismic bracing resists horizontal motion. Braces are installed to resist both lateral (perpendicular to the pipe) and longitudinal (parallel to the pipe) swaying.

What is an Armover sprinkler?

An armover is defined in Section 3.5. 3 as a horizontal pipe that extends from a branch line to a single sprinkler or a sprinkler above and below a ceiling. There is no limitation on the length of the arm-over. Thus, an armover is defined differently from a branch line; it is not part of Section 9.3.

What are the different types of fire sprinkler heads?

There are 4 common varieties of fire sprinkler heads: pendent, upright, sidewall & concealed - each with their own particular use.

Can you use PEX for fire sprinkler system?

NFPA 13D-approved for use in multipurpose and standalone fire sprinkler systems, PEX has been shown to be an effective alternative to CPVC and copper pipe due to its easy installation and durability. Both characteristics allow contractors and builders to meet tight production schedules.

Does sprinkler pipe need to be painted red?

Color Coding

Exposed standpipes and sprinkler risers must be painted red; this color-coding must be certified (BC 903.6). All buildings must comply. Branch piping does not require color-coded painting.

What is orange PVC for?

The PVC orange pipes are one of the pipe materials that every construction needs. They are not prone to any corrosion, chemical resistant, flame retardant, and maintenance-free. PVC orange pipes and fittings are widely used for transporting water from potable and non-potable water.

How does a wet pipe sprinkler system work?

Wet Pipe Sprinkler Systems

In a wet pipe sprinkler system, the sprinkler heads connect to pipes that are filled with pressurized water. When a fire is detected, the sprinkler system activates automatically to extinguish the fire. It is a reliable fire sprinkler system that requires little maintenance.

How does a dry pendent sprinkler head work?

Dry pendent sprinklers are intended to extend into an unheated area from a wet pipe system such as in a freezer. The sprinklers are fed from a drop where the drop is free of water. A seal is provided at the entrance of the dry sprinkler to prevent water from entering until the sprinkler head activates.

What is the minimum distance between sprinkler heads?

The minimum spacing between two sprinklers is 6 feet. The maximum distance a sprinkler can be installed from a wall is half the maximum spacing between two sprinklers. The minimum distance a sprinkler can be installed from a wall is 4 inches.

Where are upright sprinkler heads used?

Upright sprinkler heads are ideal for use in regions with impediments, exposed ceilings, or difficult-to-reach locations such as beams and ducts, among other things.

What is sprinkler K factor?

In fire protection engineering, the K-factor formula is used to calculate the discharge rate from a nozzle. Spray Nozzles can be fire sprinklers or water mist nozzles, hose reel nozzles, water monitors and deluge fire system nozzles.

When it is important that the inadvertent release of water be minimized even if the sprinkler pipes are accidentally broken which system is used group of answer choices?

When it is important that the inadvertent release of water be minimized, even if the sprinkler pipes are accidentally broken, which system is used? A foam/water system is an automatic system that operates in the same manner as a regular: deluge system.