Link points to Internet Archive / others. Not hosted by InfraLens. Details
IS 902:1992 is the Indian Standard (BIS) for suction hose couplings for fire fighting purposes. This standard lays down the requirements for materials, dimensions, construction, and testing of suction hose couplings used for firefighting purposes. It is used by mechanical engineers, fire safety professionals, and manufacturers to ensure that fire pump suction couplings provide a reliable, leak-proof, and airtight connection under both vacuum and pressure conditions.
Specification for Suction Hose Couplings For Fire Fighting Purposes
! Ensure proper matching of threads; suction couplings typically use specific round threads to prevent damage and cross-threading during rapid deployment.
! Aluminum alloy couplings must be properly anodized to prevent severe corrosion, especially when stored or used in damp or coastal environments.
! Always verify the condition of the rubber washer (conforming to IS 937); a damaged washer will break the vacuum, causing the fire pump to fail to draft water.
BS 336:2010BSI - British Standards Institution, UK
HighCurrent
Fire fighting hose couplings and ancillary equipment
Specifies round thread suction hose couplings that are dimensionally and functionally very similar to those in IS 902.
NFPA 1963:2019NFPA - National Fire Protection Association, USA
LowCurrent
Standard for Fire Hose Connections
Covers fire hose couplings, but specifies a different connection type (V-shaped NH/NST threads) not interchangeable with IS 902.
DIN 14323DIN - Deutsches Institut für Normung, Germany
LowCurrent
Suction couplings for fire fighting purposes; PN 16
Specifies couplings for suction hoses, but uses the Storz (quarter-turn, lugged) system, which is mechanically different from the threaded IS 902 design.
Key Differences
≠IS 902 specifies nominal sizes in millimeters (e.g., 63, 100, 140 mm), whereas standards like BS 336 and NFPA 1963 primarily use imperial units (e.g., 2 1/2", 4").
≠While functionally similar, the precise thread dimensions (major/minor diameters, tolerances) between IS 902 and BS 336 may have minor variations, potentially affecting interchangeability.
≠IS 902 specifies exact Indian material standards (e.g., Leaded-Tin Bronze as per IS 318, Aluminium Alloy as per IS 617), while international standards reference their respective national material specifications (e.g., BS or ASTM grades).
≠The hydrostatic test pressure in IS 902 is 21 kgf/cm² (approx. 20.6 bar), which is slightly different from the 22.5 bar specified in BS 336:2010.
Key Similarities
≈Both IS 902 and BS 336 specify a round thread profile for suction hose couplings, which is distinct from the V-shaped threads common in North America.
≈The fundamental purpose of all standards is to specify couplings for connecting large-diameter, non-collapsible suction hoses to a fire pump or hydrant.
≈The basic construction is consistent across similar standards, comprising a male threaded part, a female part with a swiveling internally threaded nut, and a sealing washer.
≈All standards mandate a hydrostatic pressure test to ensure the assembled coupling is leak-proof and can withstand typical negative and positive pressures experienced during firefighting operations.
≈The primary materials of construction are broadly similar, typically allowing for copper alloys (gunmetal/bronze) and light alloys (aluminium), prized for their durability and corrosion resistance.
Parameter Comparison
Parameter
IS Value
International
Source
Coupling Type
Screwed, Round Thread
Screwed, Round Thread
BS 336:2010
Coupling Type (for contrast)
Screwed, Round Thread
Screwed, V-Thread (NH/NST)
NFPA 1963:2019
Hydrostatic Test Pressure
21 kgf/cm² (approx. 20.6 bar)
22.5 bar
BS 336:2010
Threads per Inch (for 100 mm / 4" size)
2.5
2.5
BS 336:2010
Primary Copper Alloy Material
Leaded-Tin Bronze, Grade LTB 2 of IS 318
Gunmetal (e.g., BS 1400 Grade LG2)
BS 336:2010
Primary Aluminium Alloy Material
Aluminium Alloy, Designation 4600 of IS 617
Aluminium Alloy (e.g., BS 1490 Grade LM25)
BS 336:2010
Washer Material
Natural or synthetic rubber
Rubber compound compliant with BS EN 681-1
BS 336:2010
⚠ Verify details from original standards before use
What nominal sizes of suction couplings are covered under IS 902?+
The standard specifies requirements for 75 mm, 100 mm, and 140 mm nominal sizes.
What is the mandatory pressure test for these couplings?+
The completely assembled coupling must withstand a hydraulic pressure of 2.1 MN/m² (21 kgf/cm²) for 2.5 minutes without showing signs of leakage or sweating.
What materials are permitted for manufacturing these couplings?+
Typically Leaded Tin Bronze (Gunmetal) conforming to IS 318 or Aluminum Alloy conforming to IS 617.