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IS 9762:1994 is the Indian Standard (BIS) for polyethene floats (spherical) for float valves. This standard specifies the requirements for materials, dimensions, construction, and performance of spherical polyethene floats. These floats are intended for use with float-operated valves (ballcocks) in water closets and water supply storage cisterns.
Specification for floats (plastics) for float operated valves for cold water services
Directly specifies requirements for plastic floats, including spherical types, for float valves.
AS 1910-2004Standards Australia, Australia
HighCurrent
Water supply — Float-operated control valves
Covers the entire float-operated valve assembly, including specific requirements for the associated floats.
ASSE 1002-2017ASSE/ASME/CSA, USA/Canada
LowCurrent
Performance Requirements for Anti-Siphon Fill Valves (Ballcocks) for Gravity Water Closet Flush Tanks
A performance standard for the entire valve assembly, where float integrity is tested functionally.
Key Differences
≠IS 9762 specifies only spherical floats, whereas BS 2456:1990 also provided specifications for D-shaped and cylindrical floats.
≠The Indian standard is prescriptive about material, requiring LDPE or HDPE with defined density and MFI, while standards like AS 1910-2004 are performance-based, allowing any plastic that meets the required tests (e.g., stress cracking resistance).
≠There is a significant difference in the crushing strength requirement. For a 100 mm float, IS 9762 mandates withstanding a 1.0 kN load, while the equivalent in BS 2456:1990 was only 0.2 kN.
≠The hot water test in IS 9762 is more severe in temperature (80°C for 2 hours) compared to BS 2456:1990 (60°C for 1 hour), indicating different assumptions about potential failure conditions.
Key Similarities
≈Both IS 9762 and its closest equivalent, BS 2456, specify a two-piece welded construction for spherical floats with a secure threaded boss for connection.
≈Core performance tests for leakage (watertightness) under internal pressure are fundamental requirements in both the IS code and its international counterparts.
≈The standards mandate that the threaded connection for attaching the float to the valve arm must be compatible with standard pipe threads of their respective regions (e.g., BSP threads for both IS 9762 and BS 2456).
≈All relevant standards require the float to be durable and resistant to degradation from typical cold water service conditions, which is verified through various physical and environmental tests.
Parameter Comparison
Parameter
IS Value
International
Source
Nominal Size Range (Spherical)
75 mm to 300 mm
90 mm to 300 mm
BS 2456:1990
Thread Type
BSP threads as per IS 554
Parallel threads as per BS 21
BS 2456:1990
Hydraulic Leakage Test (Internal Pressure)
30 kPa for 1 min
20 kPa for 1 min
BS 2456:1990
Hot Water Test
Submerged at 80 ± 2 °C for 2 hours
Submerged at 60 ± 2 °C for 1 hour
BS 2456:1990
Crushing Test Load (for 100mm float)
1.0 kN for 1 minute
0.2 kN for 1 minute
BS 2456:1990
Wall Thickness (for 100mm float)
1.50 mm (minimum)
1.25 mm (minimum)
BS 2456:1990
Material Specification
Prescriptive: LDPE or HDPE with defined properties (density, MFI)
Performance-based: Any plastic meeting test requirements
AS 1910-2004
⚠ Verify details from original standards before use
Key Values6
Quick Reference Values
Material specifiedLow-density polyethylene (LDPE) conforming to IS 7328
Nominal diameters specified100 mm, 125 mm, and 150 mm
Minimum wall thickness1.0 mm
Leakage test internal air pressure15 kPa for 2 minutes
Low-density polyethylene (LDPE) that conforms to the requirements of IS 7328 (Clause 3.1).
What are the standard sizes for spherical floats under this IS code?+
The standard specifies three nominal diameters: 100 mm, 125 mm, and 150 mm (Table 1).
How is the leakage test performed?+
The float is subjected to an internal air pressure of 15 kPa for 2 minutes while submerged in water. There should be no signs of air leakage (Clause 6.3).
What information must be marked on the float?+
The float should be marked with the manufacturer's name or trade-mark and its nominal size (Clause 8.1).