// CODE SNIPPET
8.16 Piping Installation
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At least one listed indicating valve shall be installed in each source of water supply.
Valves on connections to water supplies, sectional control and isolation valves, and other valves in supply pipes to sprinklers and other fixed water-based fire suppression systems shall be supervised by one of the following methods:
- Central station, proprietary, or remote station signaling service
- Local signaling service that will cause the sounding of an audible signal at a constantly attended point
- Valves locked in the correct position
- Valves located within fenced enclosures under the control of the owner, sealed in the open position, and inspected weekly as part of an approved procedure
Where control valves are installed overhead, they shall be positioned so that the indicating feature is visible from the floor below.
Where there is more than one source of water supply, a check valve shall be installed in each connection.
Check valves shall be installed in a vertical (flow upwards) or horizontal position in accordance with their listing.
When a pump is located in a combustible pump house or exposed to danger from fire or falling walls, or when a tank discharges into a private fire service main fed by another supply, either the check valve in the connection shall be located in a pit or the control valve shall be of the postindicator type located a safe distance outside buildings.
Identification signs shall be provided at each valve to indicate its function and what it controls.
In portions of systems where all components are not listed for pressure greater than 175 psi (12 bar) and the potential exists for normal (nonfire condition) water pressure in excess of 175 psi (12 bar), a listed pressure-reducing valve shall be installed and set for an outlet pressure not exceeding 165 psi (11 bar) at the maximum inlet pressure.
Where post-indicator valves are used, they shall be set so that the top of the post is 32 in. to 40 in. (800 mm to 1.0 m) above the final grade.
Post-indicator valves shall be properly protected against mechanical damage where needed.
When used, valve pits shall be of adequate size and accessible for inspection, operation, testing, maintenance, and removal of equipment contained therein.
Valve pits shall be constructed and arranged to properly protect the installed equipment from movement of earth, freezing, and accumulation of water.
Poured-in-place or precast concrete, with or without reinforcement, or brick (all depending upon soil conditions and size of pit) shall be appropriate materials for construction of valve pits.
Where the water table is low and the soil is porous, crushed stone or gravel shall be permitted to be used for the floor of the pit. [See Figure A.8.17.2(b) for a suggested arrangement.]
Valve pits located at or near the base of the riser of an elevated tank shall be designed in accordance with Chapter 9 of NFPA 22.
All sprinkler pipe and fittings shall be installed so that the system can be drained.
On wet pipe systems, sprinkler pipes shall be permitted to be installed level.
In dry pipe system, branch lines shall be pitched at least 1/2 in. per 10 ft (4 mm/m), and mains shall be pitched at least 1/4 in. per 10 ft (2 mm/m) in nonrefrigerated areas.
In preaction systems, branch lines shall be pitched at least 1/2 in. per 10 ft (4 mm/m), and mains shall be pitched at least 1/4 in. per 10 ft (2 mm/m).
Branch lines shall be pitched at least 1/2 in. per 10 ft (4 mm/m), and mains shall be pitched at least 1/2 in. per 10 ft (4 mm/m) in refrigerated areas.
Provisions shall be made to properly drain all parts of the system.
Drain connections for systems supply risers and mains shall be sized as shown in Table 220.127.116.11.2.
Table 18.104.22.168.2 Drain Size
|Riser or Main Size |
|Size of Drain Connection |
|Up to 2 (50)||3/4 (20) or larger|
|21/2 (65), 3 (80), 31/2 (90)||11/4 (32) or larger|
|4 (100) and larger||2 (50) or larger|
Drains shall discharge outside or to a drain connection capable of handling the flow of the drain. [See Figure A.22.214.171.124(b).]
Where drain connections for floor control valves are tied into a common drain riser, the drain riser shall be one pipe size larger downstream of each size drain connection tying into it.
Where subject to freezing, a minimum 4 ft (1.2 m) of exposed drain pipe shall be in a heated area between the drain valve and the exterior wall when drain piping extends through the wall to the outside.
Auxiliary drains shall be provided where a change in piping direction prevents drainage of system piping through the main drain valve.
Where the capacity of isolated trapped sections of pipe is 50 gal (200 L) or more, the auxiliary drain shall consist of a valve not smaller than 1 in. (25 mm), piped to an accessible location.
Where the capacity of trapped sections of pipes in wet systems is less than 5 gal (20 L), one of the following arrangements shall be provided:
- An auxiliary drain shall consist of a nipple and cap or plug not less than 1/2 in. (15 mm) in size.
- An auxiliary drain shall not be required for trapped sections less than 5 gal (20 L) where the system piping can be drained by removing a single pendent sprinkler.
- Where flexible couplings or other easily separated connections are used, the nipple and cap or plug shall be permitted to be omitted.
Tie-in drains shall not be required on wet pipe systems and preaction systems protecting nonfreezing environments.
Auxiliary Drains for Dry Pipe Systems and Preaction Systems.
Auxiliary drains located in areas subject to freezing shall be accessible.
Auxiliary drains located in areas maintained at freezing temperatures shall be accessible and shall consist of a valve not smaller than 1 in. (25 mm) and a plug or a nipple and cap.
Where the capacity of isolated trapped sections of system piping is more than 5 gal (20 L), the auxiliary drain shall consist of two 1 in. (25 mm) valves and one 2 in. × 12 in. (50 mm × 300 mm) condensate nipple or equivalent, accessibly located in accordance with Figure 126.96.36.199.3.5, or a device listed for this service.
FIGURE 188.8.131.52.3.5 Dry System Auxiliary Drain.
Tie-in drains shall be provided for multiple adjacent trapped branch pipes and shall be only 1 in. (25 mm). Tie-in drain lines shall be pitched a minimum of 1/2 in. per 10 ft (4 mm/m).
Systems with low point drains shall have a sign at the dry pipe or preaction valve indicating the number of low point drains and the location of each individual drain.
Direct interconnections shall not be made between sprinkler drains and sewers.
The drain discharge shall conform to any health or water department regulations.
Where drain pipes are buried underground, approved corrosion-resistant pipe shall be used.
Drain pipes shall not terminate in blind spaces under the building.
Where exposed to the atmosphere, drain pipes shall be fitted with a turned-down elbow.
Drain pipes shall be arranged to avoid exposing any of the water-filled portion of the sprinkler system to freezing conditions.