Download text file (WetPipeLowFlow.zip)

WET PIPE LOW FLOW FOAM SYSTEM
The sprinkler system shall be a closed head wet pipe/AFFF foam sprinkler system. The system shall be designed to provide adequately proportioned foam water solution at low water flows past the proportioning device. The proportioning system shall provide foam at initial fire conditions equal to or at a greater design percentage below the minimum listed flow of the proportioning system. The system shall be installed in accordance with NFPA 16, Standard for the Installation of Deluge Foam-Water Sprinkler and Foam-Water Spray Systems, NFPA 13, Standard for the Installation of Sprinkler Systems, and occupancy standards pertaining to the system installation.

SYSTEM DEVICES

System Design
(Insert applicable system design.)

Low Flow Proportioning System
The low flow proportioning system shall be totally automatic and mechanical in nature. Electrical appliances, electric devices, electric valves, and electric pumps shall be strictly prohibited. The proportioning system shall be of such a type that all valves, devices, foam bladder tanks and appurtenances are of a listed and approved assembly, with foam concentrate being supplied.

Low flow foam proportioning shall be accomplished by positive injection of foam concentrate of a higher pressure into a lower water pressure stream passing the concentrate controller (proportioner); the differing pressures shall be "balanced" by means of a spool valve with an internal balanced design (ILBP).

The pressure difference (minimum 15 PSI) between the foam concentrate and the water pressure stream passing by the proportioning device shall be created by supplying the foam bladder tank with system supply pressure and reducing the discharge pressure of the system supply. A pilot operated pressure control valve, listed and approved as part of the proportioning system, shall be installed to reduce the supply pressure of the system riser.

The flow of water through the system riser shall cause the concentrate control valve to open, allowing foam concentrate to flow into the ILBP to be balanced to the existing water flow. The concentrate control valve shall automatically reset once the flow of water has ceased. The concentrate control valve shall be listed as a Halar coated fire protection valve and be of a right angle deluge valve design. Water flow in the system riser shall be directed past a listed and approved pilot operated pressure control valve to a listed and approved alarm valve. The alarm valve alarm port shall be utilized for water flow alarms and to release the prime pressure of the Halar coated right angle deluge valve. Prime pressure of the Halar coated concentrate control valve shall be released when water flow from the alarm valve alarm port back pressures a pressure operated relief valve (PORV), venting the priming water feed and draining the priming chamber water. Priming water pressure shall be reestablished in the priming chamber when water flow is no longer present in the alarm valve; thereby, eliminating the flow through the alarm port, which will allow the PORV to close and reestablish prime pressure on the Halar coated concentrate control valve.

Pilot Operated Pressure Control Valve
Wet pipe/foam sprinkler systems shall require a reduced discharge pressure at the system riser and shall employ the use of a listed and approved pilot operated pressure regulating valve that has been approved with the proportioning system. The pressure regulating valve shall be factory set and field adjustable to constant pressure regardless of inbound pressure fluctuations. The pilot operated pressure control valve shall be listed for water working pressures of not less than 175 PSI. The pilot operated control valve shall have, as part of its assembly: a right angle pattern flow control valve, a pilot pressure regulating valve, a speed control assembly, and listed galvanized trim piping assembled and tested by the manufacturer. The pilot operated pressure control valve shall be UL listed and FM approved as an integral part of the proportioning system. The pilot operated pressure control valve manufacturer is to be The Viking Corporation, and the Model shall be A-2.

Foam Bladder Tank
The foam bladder tank employed in low flow foam system shall be an ASME code pressure vessel. The foam bladder tank utilized shall have been listed for use with the foam concentrate and proportioning method utilized. The foam bladder tank shall be compatible with Viking's Low Flow Foam System. The foam bladder tank shall adhere to the requirements set forth in NFPA 11, Standard for Low-Expansion Foam and NFPA 16, Standard for the Installation of Deluge Foam-Water Sprinkler and Foam-Water Spray Systems. The foam bladder tank shall be UL listed and FM approved.

Concentrate Control Valve
Deluge valves that are utilized as concentrate control valves and are to be supplied by AFFF or AR-AFFF shall utilize a 90° pattern type of deluge valve manufactured with a corrosive resistant Halar coating. The concentrate control valve shall be externally resettable by hydraulic means. The concentrate control valve shall employ a positive venting device (PORV) on the priming line to release prime pressure from the top of the deluge valve. The PORV shall automatically reset and reprime deluge valve once back pressure has been removed. The inlet and outlet connections of the deluge valve can be flanged by flanged, flanged by grooved, or threaded by threaded, respectively. The concentrate control deluge valve shall have a working pressure of not less than 250 PSI unless listed for higher pressures. The concentrate control valve shall be primed with an indicating control valve followed by an inline strainer, check valve, and a 1/8" restricted orifice in line prior to the inline PORV. The concentrate control valve trim shall be compatible and shall be installed following the manufacturer's installation instructions. The Halar Coated Concentrate Control Deluge Valve manufacturer is to be The Viking Corporation. The Model shall be E-2 or E-4.

Foam Concentrate Piping
Foam concentrate piping shall be compatible with foam concentrate to be used. The foam provider shall be consulted for acceptable materials of construction. Foam concentrate piping shall be designed for the least equivalent feet of pipe run from bladder tank discharge outlet to proportioning device and water supply to bladder tank. Excessive use of elbows and tees shall be avoided. Foam concentrate piping shall be substantially secured and restrained against movement, thrust, and vibration. Foam concentrate piping shall be protected from excessive heat and freezing temperatures. Foam concentrate piping shall be installed with a fitting such as a grooved coupling or union to be readily removed between proportioning assembly and concentrate control valve.

In-Line Balanced Proportioner (ILBP)
the In-Line Balanced Proportioner (ILBP) assembly shall be factory assembled and include a listed and approved concentrate controller, brass connecting nipples, duplex gauge, braided sensing lines, and an internally balancing designed spool valve. The ILBP shall have a working pressure for incoming foam concentrate of 200 PSI. The spool balancing valve shall be equipped with a copper sensing tube for the primary function of sensing flowing water pressure past the concentrate controller and adjusting the flow of foam through internal port openings by allowing the upper the valve disc to raise or lower the spool assembly connected to the upper valve disc. The ILBP shall work on a minimum 15 PSI differential pressure between the higher incoming foam concentrate and the lower flowing water pressure inlet to the concentrate controller. Braided sensing lines shall be installed from the duplex gauge and the foam and water pressures. The duplex gauge shall display water pressure with a needle black in color and display foam pressure with a needle red in color. A braided sensing line for water pressure shall be installed from a ½" outlet on the system riser provided below the concentrate controller by the fire sprinkler contractor. The ILBP shall be UL listed and FM approved as an assembly with the foam concentrate and as an integral part of the complete system (bladder tank, pilot operated pressure control valve, ILBP, etc). The In-line Balanced Pressure Proportioner manufacturer is to be The Viking Corporation, and the Model shall be LFF.

Alarm Valve
The alarm valve shall be UL listed and FM approved. The alarm valve shall be equipped with a removable cover/clapper assembly for periodic inspection of clapper and seat assembly in accordance with NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems. The alarm valve shall be listed for installation in the vertical or horizontal position. The alarm valve shall be equipped with gauge connections on the system side and supply side of the valve clapper. The alarm valve shall be equipped with an external bypass to eliminate false alarms if water flow is less than that of the flow of a single fire sprinkler. The alarm valve trim piping shall be galvanized and be listed and approved as part of the valve assembly. The alarm valve shall be constructed with a ductile iron body and be listed and approved for a maximum water working pressure of 250 PSI. The alarm valve shall be equipped with a pressure retard chamber as part of the alarm line trim. The alarm valve manufacturer is to be The Viking Corporation, and the Model shall be J-1.

Retard Chamber
Ported alarm connections on sprinkler riser valve are to be piped to a retard chamber to absorb variable pressure surges. The alarm pressure switch is to be installed on the retard chamber with circuit vent trim to eliminate vapor or hydraulic lock against circuit closer. The Retard Chamber manufacturer is to be The Viking Corporation, and the Model shall be C-1.

Foam Concentrate
Aqueous Film Forming Foam (AFFF) or Alcohol Resistant Aqueous Film Forming Foam (AR-AFFF) shall be utilized. Water-soluble liquids shall be protected with Alcohol resistant type foam concentrate. Foam concentrates shall be synthetic and shall be stored in accordance with the manufacturer's instructions. Foam concentrates shall be listed for use for the protection application imposed. Foam concentrates shall be listed and approved for the discharge outlets utilized in the protection scheme. Foam concentrates shall be UL listed and FM approved. Foam concentrates shall be listed and approved for use with Viking's Low Flow Foam System. Foam concentrates shall be proportioned for a minimum 1% or 3% concentration in accordance with their listings.

Discharge Devices
Closed head sprinklers or nozzles that have been specifically tested and found suitable for the discharge of low expansion synthetic foam/water solution shall be installed. Standard sprinklers or closed head nozzles used for discharge outlets shall have been tested for minimum densities or minimum pressures as foam/water solution discharge outlets. Discharge devices shall be UL listed or FM approved for the application for which they are used. Closed head sprinklers and closed head nozzles shall be UL listed or FM approved for use with the foam and flammable liquid being protected. All sprinklers or nozzles that are to discharge foam/water solution are to be manufactured by The Viking Corporation.

Waterflow Pressure Switch
Water flow will activate an alarm by way of an alarm pressure switch. The alarm pressure switch shall be compatible with system devices. The alarm pressure enclosure shall be UL listed and FM approved for the application in which it is used. The alarm pressure switch shall have the ability to be wired for Class A or Class B service. The alarm pressure switch shall be constructed with a ½" brass pressure connection. The alarm pressure switch manufacturer shall be The Viking Corporation, Part Number 09470 or 09471.

System Overhead Piping
Overhead sprinkler piping shall be in accordance with materials deemed acceptable by NFPA 13, Standard for the Installation of Sprinkler Systems, NFPA 16A, Standard for the Installation of Closed-Head Foam-Water Sprinkler Systems, and all other applicable building standards.

System Control Valve
The low flow foam system control valve shall consist of a listed indicating type of control valve. The control valve shall be listed for use in fire protection systems. The control valve shall be rated for system working water pressure, but in no case shall be listed for pressure less than 175 PSI.

Hangers and Supports
System piping shall be substantially supported from the building structure. The installation of hangers and supports shall adhere to the requirements set forth in NFPA 13, Standard for the Installation of Sprinkler Systems. Materials used in the installation or construction of hangers and supports shall be listed and approved for such application. Hangers or supports not specifically listed for service shall be designed and bear the seal of a professional engineer.

Fire Department Connection
A system fire department connection shall be provided on the system riser in accordance with NFPA 16A, Standard for the Installation of Closed-Head Foam-Water Sprinkler Systems. The fire department connection shall be of a brass body with an integral clapper assembly to separate flow between inlets. The fire department connection shall be installed in an area accessible for the first response unit. The actual fire department location shall be installed and located only after proper coordination with fire officials. The fire department connection shall be UL listed and FM approved for fire protection use.

Underground Piping
Piping and fittings used for the installation of underground water mains shall be listed for such service. Local water system requirements shall be adhered to. Compatible fittings and connection methods shall be reviewed with the water department authority. The standards of the AWWA and NFPA 24, Standard for the Installation of Private Fire Service Mains and Their Appurtenances shall be minimum installation guidelines.

Drains and Flushing Connections
System drains shall adhere to the requirements set forth in NFPA 13, Standard for the Installation of Sprinkler Systems. Flushing connections shall be provided where system piping is subject to accumulation of sediments or where periodic flushing is required by the Authority Having Jurisdiction. System auxiliary drains shall be installed so that the drain valve is accessible and labeled as a sprinkler system drain. Drains shall terminate to the exterior of the building where practical. Drains that do terminate to the exterior shall be installed with a 45° elbow directed to a splash block or other permanent erosion limiting material.

Riser Test Connections
A test connection shall be provided on the system riser with a downstream isolation valve for the purpose of testing foam proportioning. The system test header shall be of adequate size for at least a mid-range flow of the proportioning system. The system test header shall be installed with a means of draining any trapped sections of discharge piping subject to freezing.

System Supervision
Control valves larger than 2" in size shall be equipped with UL listed and FM approved supervisory switches. Control valves 2" and smaller shall be sealed in the position of their normal operating condition. Others shall execute the termination of supervisory switch wires. Supervisory switches shall be Potter Electrical Signal Company Control Valve Supervisory Switch.

System Commissioning
The foam water sprinkler system shall be tested in accordance with NFPA 11, NFPA 13, NFPA 16, and all other applicable codes and jurisdictions. An owner's representative, local fire officials and a representative of the installing contractor shall witness foam-proportioning tests. Additional foam concentrate shall be provided for testing by the installing contractor. The installing contractor shall provide maintenance and material safety data sheets (MSDS) to the owner.

Foam Products
Concentrate Control Valve
Concentrates
Bladder Tank
Proportioners
Discharge Devices