Long-range water-cum-foam monitor with self-inducting, aspirating and non-aspirating jet and spray/fog nozzle forfire fighting -Specification
2008 Edition

IS 15811 specifies materials based on the waterway type used in the foam monitors: Carbon Steel, Stainless Steel, or Copper Alloy. Each component, such as inlet flanges, reducers, elbows, swivel joints, worm shafts, and nozzles, must conform to specific Indian Standards (e.g., IS 2002 Grade I for carbon steel inlet flanges, IS 6911 for stainless steel plates, IS 318 Grade LTB-II for copper alloy parts). The choice of materials should be finalized through mutual agreement between the purchaser and manufacturer to ensure compatibility and durability.

The standard mandates testing water-cum-foam monitors at an inlet pressure of 0.7 N/mm². Water is used for assessing foam induction rates, which must be 3%-4% for a 3% induction rate and 6%-7% for a 6% rate. Foam concentrate is employed during expansion and jet reach tests. The foam spray or fog angle must be at least 120°. Effective reach is calculated as the overall jet reach minus 5%, with aspirating nozzles having a 10% reduced reach compared to non-aspirating types. Table 2 provides detailed flow rates and minimum horizontal reach distances for various monitor sizes.

IS 15811 covers two main nozzle categories: aspirating and non-aspirating. Aspirating nozzles consist of a body and barrel, mixing foam concentrate with air to produce expanded foam jets or sprays. Non-aspirating nozzles are available as jet or spray/fog types that allow rapid switching between modes without air induction, directly mixing foam concentrate. Additional features include fixed or rotating teeth rings to enhance fog application. The aspirating nozzles focus on producing thick foam blankets, while non-aspirating nozzles provide flexible jet or spray patterns.

The monitors undergo hydraulic pressure testing at 2.3 N/mm² for five minutes. During this test, the assembly must be rotated horizontally five times clockwise and five times counterclockwise, and vertically cycled five times up and down. No leakage at swivel joints or other connections is permitted. The jet ratio controller, if included, is tested separately under the same conditions. Following the leakage test, performance is verified at 0.7 N/mm² for flow rates, induction percentages, and reach distances.

Monitors designed for seawater service must avoid aluminium and carbon steel components due to high corrosion risk. Instead, stainless steel or copper alloy materials are mandated for waterways and exposed parts. Joints should be welded, screwed, or flanged with adequate sealing and locking mechanisms. Components like swivel joints, worm shafts, and nozzles are specified to be corrosion-resistant materials. Material compatibility and corrosion resistance must be confirmed between purchaser and manufacturer to ensure longevity in marine environments.

The monitors shall provide 360° continuous horizontal rotation via a swivel joint and at least 135° vertical movement (90° upward and 45° downward). Traversing mechanisms include single-handle bars with manual locks or worm and worm wheel assemblies featuring irreversible self-locking for unattended operation. Smaller monitors (63 and 80 mm nominal size) may use manual locks, while larger ones (100 to 150 mm) require worm and worm wheel mechanisms. These assemblies must withstand hydraulic pressure testing without leakage.

Each water-cum-foam monitor must be permanently and clearly marked with the manufacturer’s name and trademark, nominal size in millimeters, serial number, year of manufacture, maximum working pressure in N/mm², and flow rate at the specified pressure along with foam concentrate induction rate. These markings ensure product traceability and compliance. Additionally, the monitor may bear the BIS Standard Mark subject to licensing under the Bureau of Indian Standards Act, 1986. Numerical values should be rounded off following IS 2:1960.