polyethene floats (spherical) for float valves
1994 Edition

Overview of Scope This section outlines the dimensions, material requirements, and testing procedures for spherical polyethylene floats used in float valves.

Table: Float Dimensions (Clause 7.2)

Note: Thread dimensions conform to IS 4218 coarse series.

Sampling and Acceptance Criteria (Clause 9.4.2)

All sampled floats must successfully pass tests for leakage, water absorption, deflection, impact, and boss integrity.

Key References and Dimensions

This section consolidates important dimensional data and sampling tables from IS 9762.

Float Dimensions and Wall Thickness (Clause 7.2, Table 1):

Thread tolerances comply with IS 4218 (coarse series).

Definitions (Clause 3.0)

Terms relevant to the standard are defined to ensure clarity in interpretation.

Dimensional Specifications (Clause 7.2)

Note: Threading tolerances follow IS 4218 coarse series.

Float Identification (Clause 3.0, 3.2)

Floats are categorized as High Pressure (HP) or Low Pressure (LP) followed by their nominal size in millimeters.

Examples:

• HP 25: High Pressure float, 25 mm nominal size
• LP 40: Low Pressure float, 40 mm nominal size

Material Specifications

• Manufactured from HDPE conforming to PEBW A50 T 090 or PEBN A50 T 090 as per IS 7328:1992.
• Recycled material from the same manufacturer may be used up to 10% of the batch.

Critical Dimensions

Refer to Table 1, Clause 7.2 for detailed dimensions including diameter, wall thickness, threading, and insert thicknesses.

Wall Thickness Requirements (Clauses 6.2 and 6.2.1)

Minimum wall thickness C varies according to the nominal float size:

Dimensional Data (Clause 7.2, Table 1)

Includes float diameters, wall thickness, threading sizes, and insert thicknesses.

Sampling and Acceptance Tests (Clause 9.4.2)

Sampling sizes and acceptance numbers for various lot sizes are defined to ensure compliance.

Dimensional Details (Clause 7.2)

Tolerances (Clause 6.1.1)

• Diameter variation tolerance is ±2.5 mm.

Thread tolerances follow IS 4218 (coarse series).

Dimensional and Threading Specifications (Clause 7.2)

Details on float diameter, wall thickness, boss threading, insert dimensions, and thread length are specified to ensure manufacturing precision.

Sampling and Acceptance Testing for Manufacturing (Clause 9.3.1)

This section ensures that production meets quality standards through defined sampling plans.

Essential Tests (Clause 9.4.2)

Floats undergo tests for leakage, water absorption, deflection, impact resistance, and boss integrity. Any failure results in rejection.

Sampling and Acceptance (Table 3)

Deflection Test

Conducted as per Fig. 1 in the standard using a counterbalance float to apply load; maximum deflection limits apply.

This section guarantees the floats perform reliably under service conditions.

Sampling Guidelines (Clauses 9.1, 9.3.1, 9.4.1)

Sampling size depends on the size of the production lot and test type.

Sampling Plan for Dimensional and Workmanship Tests (Table 2)

Acceptance Criteria

A lot is accepted if the number of defective units does not exceed the acceptance number.

This ensures statistically valid quality assurance.

Marking Requirements (Clause 10.1)

Each float must be clearly marked with:

• Manufacturer’s name or trademark
• Float designation (HP or LP with size)
• Batch or lot number

BIS Certification Mark (Clause 10.2)

Floats may carry the Bureau of Indian Standards (BIS) Standard Mark, governed by BIS Act 1986 licensing rules.

Sampling and Testing

Following Clause 9.4.2 and Table 3, samples are tested for leakage, water absorption, deflection, impact, and boss integrity with zero defect tolerance.

This section ensures traceability and quality control compliance.

Test Method (Clause 8.1 & Annex A)

1. Weigh the dry float to record initial mass (M1).
2. Immerse the float in water maintained at 55 ± 2°C, with water level at least 50 mm above the float.
3. Keep immersed continuously for 100 hours.
4. Check for any leakage during immersion.
5. Remove float, wipe dry the surface, allow brief air drying, then weigh again (M2).
6. Calculate water absorption percentage:

[ \text{Water Absorption (5)} = \frac{M_2 - M_1}{M_1} \times 100 ]

7. Acceptance: Water absorption must not exceed 0.5%, and no leakage should be observed.

This test ensures float durability by limiting water ingress.

Objective

Measure vertical deflection of the float under specified loading conditions.

Acceptance Criteria

Maximum deflection allowed is 7 mm with no permanent deformation.

Test Setup

Conduct as per Fig. 1 in Annex B using a counterbalance float to apply load.

Procedure

Gradually apply load and measure deflection at the midpoint or specified location.

This test verifies structural resilience of floats.

Overview

The boss and associated float must resist deformation under mechanical loads as per Annex C.

Construction

Bosses are integral to the float and fitted with copper alloy corrosion-resistant threaded inserts.

Test Method

Apply designated loads and inspect for visible distortion or damage. No deformation should occur.

Design Considerations

Cross-sectional area and material strength must ensure stress under load does not exceed allowable limits.

This ensures mechanical integrity of the boss during operation.

Committee Details

The Sanitary Appliances and Water Fittings Sectional Committee (CED 3) manages IS 9762.

• Chairman: Shri S. Prakash (Delhi Water Supply and Sewage Disposal Undertaking)
• Members: Professionals from government agencies, research institutes, water boards, municipal corporations, Indian Water Works Association, BIS, and industry representatives.
• Member Secretary: Shri S. S. Sethi (Director, Civil Engineering, BIS)

Sampling Plan for Quality Control

Lots are accepted if defective units are within permissible limits.

This committee framework ensures expert input and quality assurance.