(2) The minimum size of the riser shall be 4 in. (100 mm) unless hydraulic calculations indicate that a smaller size riser will satisfy sprinkler and hose stream allowances.
NFPA 13 prescribes the following minimum sizes for drains on supply risers and mains: 4” (100 mm) and larger risers or mains: 2” (50 mm) valves or larger. 2 1/2”, 3”, 3 1/2” (65 mm, 80 mm, or 90 mm) risers or mains: 1 1/4” (32 mm) valves or larger.
We often get asked 'How big is a Dry Riser pipe'? Dry Risers are either 4 inch or 6 inch internal diameter. Most Dry riser systems are Designed and installed with 4 inch pipe (114mm to the outside wall).
The sprinkler pipe size from the water supply source to a sprinkler shall be not less than 3/4 of an inch (20 mm) in diameter. Threaded adapter fittings at the point where sprinklers are attached to the piping shall be not less than 1/2 of an inch (15 mm) in diameter.
All fire sprinkler riser rooms shall be a minimum of 36 sq. ft., with no dimension less than 6 ft., and shall be large enough to accommodate maintenance and testing actives.
“Such rooms shall be of a size that will allow a minimum of 36-inch clearance around all portions of the fire pump assembly and in front of the fire alarm panel(s). All risers shall have a minimum of 36″ clear space at the front and 18″ on the remaining sides.”
Pipe sizing
If the building is protected with an automatic sprinkler system, then the minimum combined standpipe size can be 4 in. (100 mm) if hydraulically calculated. The branch lines of the standpipe system are to be sized hydraulically but cannot be smaller than 2 -1/2½ in. (65 mm).
If you choose to use PVC pipe for your irrigation laterals, make sure to use pipe that is at least 3/4" thick. 1/2" inch laterals clog very easily. If you choose to use fittings, most common PVC fitting types work fine.
One of the most commonly used sizes of PVC pipe for irrigation systems are 13mm, 19mm, and 25mm. For irrigation laterals, PVC pipes that are at least ¾” thick (19.05mm) are preferred since those that are ½” thick (12.7mm) clog much faster and often.
Standard Stair Riser Height Requirements
2 requires that stair riser heights shall be 7 inches (178 mm) maximum and 4 inches (102 mm) minimum.
minimum width of staircase should be between 5 to 7 feet and tread width should be 1 foot. Riser height should be 6 inches for the commercial buildings.
Building Officials and Code Administrators (BOCA) Riser height 4 to 7 in (102 to 178 mm), tread depth 11 in (279 mm) minimum (exclusive of overhang).
Standard risers come in fixed lengths, so getting the correct riser is crucial to ensuring your sprinkler head sits at the right height. Sprinkler heads need to sit above the ground, at an ideal height for uninterrupted water flow and even coverage.
Yes, both the IBC and NFPA 13 address the situation. One line that is included in the IBC specifically says that sprinklers “shall not be omitted from any room merely because it...contains electrical equipment”.
Each sprinkler system zone in buildings that are more than 420 feet (128 m) in building height shall be supplied by not fewer than two risers. Each riser shall supply sprinklers on alternate floors. If more than two risers are provided for a zone, sprinklers on adjacent floors shall not be supplied from the same riser.
On average, it will take 30 minutes to get a half inch of water. So, 20 minutes, three times per week will give a lawn about an inch of water. This formula works best with healthy, well-cultivated soil.
This will primarily be determined by the total flow rate and pressure you have available at your source. For example, you generally have a flow rate of 10 gpm from a ¾-inch spigot where you connect your hose. With your 10 gpm flow rate at your spigot, you could run two sprinklers at 5 gpm each.
In theory, there isn't much of a difference between a 1/2” and a 3/4” fire sprinkler. After all, these sizes refer only to how the thread engages with the pipe. But a quarter-inch increase in exterior size has a substantial impact on how much more water can flow through the connection's interior waterway.
Specifically, “PEX or any other listed nonmetallic material can now be used in a standalone wet fire sprinkler system 'if the maximum static pressure from the water supply does not exceed 80 psi' – or a pressure release valve and an automatic means of pressure release is used when the pressure from the water supply is ...
If your home's water capacity was 10 GPM, you could place 3 heads per zone. Consult the Performance Charts on or inside the box your sprinkler head came in for your head's exact performance data, or locate the performance data in the Support area of this website.
The minimum pressure while flowing the required standpipe flow (500 GPM from the hydraulically most remote standpipe and 250 GPM from each additional standpipe, up to a maximum of 1000 GPM for a fully sprinklered building) shall be 100 psi at any valve outlet while flowing 250 GPM through each valve.
NFPA 14 provides all necessary requirements about the proper fixation of standpipes and hose systems to offer maximum protection against fire by delivering adequate water amounts.
Because standpipe system can be operated in many ways and provides a greater pressure at hose connections, it is more efficient in extinguishing blazing fires than automatic sprinklers are. Sprinkler systems are, however, still effective and remain enforceable in all commercial and residential buildings.