scope:

Foam fire extinguishing systems are classed in three general categories according to foam concentrate type, low, medium, and high expansion. All may be designed for manual or automatic control and are most often used to extinguish Class B fires. At present, FM Global does not specify any applications for medium expansion foam systems, nor for protection of Class A combustibles with high expansion foam systems.

A basic foam extinguishing system comprises a concentrate, a device to proportion the concentrate in the proper ratio into water, and a discharge device to deliver the foam to a burning liquid surface. A discharge device may assume the entire task of expanding the foam, or function primarily to distribute foam which has been partially or completely expanded by an upstream device, such as a foam maker. Compatible FM Approved detectors and detection and release controls are required for automatic operation of these systems, but are not included in the scope of this standard.

This standard requires the examination of complete systems. Complete systems shall be submitted along with design, installation, operation, and maintenance instructions for Approval. However, the manufacturer may, at any time, submit additional separate component parts or auxiliary equipment for use on his system. Purchased devices such as pumps, tanks, control valves, and sprinklers must also be submitted by the system manufacturer for evaluation as a part of his system, even though such devices may already be FM Approved and listed by FM Approvals. At minimum, a system shall consist of those component parts and auxiliary equipment considered necessary by FM Approvals for the system to operate satisfactorily. Incomplete systems shall not be FM Approved.

Purpose

This standard describes requirements for fixed fire extinguishing systems that use an aqueous foam as the extinguishant.

FM Approvals criteria may include, but are not limited to, performance requirements, marking requirements, examination of manufacturing facilities, audit of quality assurance procedures, and a follow-up program.