plastic equilibrium float valve for cold water services

IS 12234: Scope - Key Specifications & Tables

1. Scope Overview

• Covers specifications for float valves with horizontal and vertical inlet shanks.
• Dimensions must conform to Fig. 2A & 2B (Clause 6.4).

2. Sampling & Acceptance Criteria (Clause 8.1.3, Table 2)

• Acceptance number means max allowable defective valves in sample.

3. Test Procedure (Clause 2.1)

• One cycle = minimum 6 seconds:
  • Open valve fully in ≥1 sec
  • Hold open for 2 sec
  • Close fully in ≥1 sec
  • Hold closed for 2 sec

4. Dimensional Compliance (Clause 6.4)

• Body dimensions per Fig. 2A (horizontal inlet) and Fig. 2B (vertical inlet).

Summary Diagram: Sampling & Test Cycle

flowchart TD
    A[Start Test Cycle] --> B{Open Valve}
    B -->|≥1 sec| C[Hold Open 2 sec]
    C --> D{Close Valve}
    D -->|≥1 sec| E[Hold Closed 2 sec]
    E --> F[End Cycle]

For detailed dimensions, refer to Fig. 2A & 2B in the standard. Sampling ensures quality control based on lot size.

IS 12234: Classification - Key Sampling & Conformity Criteria

Sampling & Acceptance (Clause 8.1.3 & 8.2.2)

• Sample size depends on the lot size.
• A lot is accepted if the number of defective items ≤ acceptance number.
• Rejection occurs if defective items exceed acceptance number.

Usage:

• For quality control in valve lots.
• Ensures conformity by limiting defective items in samples.

flowchart TD
    A[Start: Identify Lot Size] --> B{Lot Size?}
    B -->|Up to 100| C[Sample 5, Accept if defects ≤ 0]
    B -->|101-150| D[Sample 8, Accept if defects ≤ 0]
    B -->|151-500| E[Sample 13, Accept if defects ≤ 1]
    B -->|501-1000| F[Sample 20, Accept if defects ≤ 1]
    B -->|>1000| G[Sample 32, Accept if defects ≤ 2]
    C --> H[Decision]
    D --> H
    E --> H
    F --> H
    G --> H

This classification ensures a statistically valid inspection process for lot acceptance.

IS 12234: Nominal Sizes for Float Valves

• Nominal Size: As per Clause 3.1, the standard nominal size for the float valve is 15 mm.

• Dimensions: Clause 6.4 specifies that valve body dimensions must conform to the sizes shown in Fig. 2A (Horizontal Inlet Shank) and Fig. 2B (Vertical Inlet Shank). These figures define the overall length, diameter, and inlet/outlet dimensions for proper fitting.

• Pressure Reducers: Clause 2.2 allows fitting of:

  • High Pressure Reducer (HP)
  • Low Pressure Reducer (LP)
    Refer to Fig. 1 for typical flow restrictor configurations.

• Sampling for Quality Control (Clause 8.1.3):

This table guides the number of valves to sample and acceptance criteria during inspection.

For exact dimensions, refer to Fig. 2A and 2B in IS 12234, which provide detailed size charts for horizontal and vertical inlet shank valves.

IS 12234: Key Specifications for Materials (Clauses 4.1 & 4.2, Table 1)

• Material Restrictions:

  • Reworked material allowed up to 15% except for valve seats where no reworked material is permitted (Clause 4.2).

• Materials for Valve Components (Table 1):

• Quality Checks (Clause 8.2.1):
  • Valves must be examined for material, manufacture, workmanship, and construction.
  • Failure in any criteria = valve is defective.

Summary Diagram: Material Flow for Float Valve Components

graph TD
    A[Valve Components] --> B[Valve Body, Inlet Shank, Back Nut, Cap, Float Arm]
    A --> C[Valve Seat]
    A --> D[Float, Flow Restrictors, Discharge Horn]
    A --> E[Diaphragm Pin]

    B -->|Material| F[Stainless Steel or Non-Corrosive Material]
    C -->|Material| G[Polyacetal (No Reworked Material)]
    D -->|Material| H[Polyacetal or Stainless Steel]
    E -->|Material| F

This ensures corrosion resistance and durability per IS 12234 standards.

IS 12234: Manufacture and Workmanship Key Points

1. Reworked Material Usage (Clause 4.2)

• Up to 15% of manufacturer's own rework material is allowed.
• Exception: No reworked material for valve seats.

2. Inspection and Testing (Clause 8.2.1 & 8.2.2)

• Valves selected per columns 1 and 2 of Table 2 must be examined for:
  • Material quality
  • Manufacture and workmanship
  • Construction integrity
• Any valve failing any requirement is defective.
• Lot acceptance depends on defective count ≤ acceptance number (column 3, Table 2).

3. Table 2 Summary (Sampling & Acceptance)

• Exact sample sizes and acceptance numbers depend on lot size (refer IS 12234 Table 2).

Summary:

• Max 15% rework allowed (except valve seat).
• Inspection per Table 2 sampling.
• Lot accepted if defectives ≤ acceptance number.

flowchart TD
    A[Manufacture] --> B[Use of Rework Material ≤15%]
    B --> C{Valve Seat?}
    C -- Yes --> D[No Rework Allowed]
    C -- No --> E[Rework Allowed]
    E --> F[Inspection per Table 2]
    D --> F
    F --> G{Defectives ≤ Acceptance Number?}
    G -- Yes --> H[Lot Accepted]
    G -- No --> I[Lot Rejected]

For exact sampling sizes and acceptance numbers, refer to Table 2 of IS 12234.

IS 12234: Construction - Key Points & Specifications

Materials (Clause 5.2)

• Parts in contact with water must not:
  • Be toxic
  • Promote microbiological growth
  • Cause taste, odor, cloudiness, or discoloration

Manufacture & Workmanship (Clause 4.2)

• Reworked material usage allowed up to 15% except for valve seats (no rework allowed).

Quality Control (Clause 8.2.2)

• Lot acceptance based on sample inspection:
  • Number of defective items ≤ acceptance number in Table 2 (sample size vs acceptance number).

Typical Acceptance Sampling Table (Example format for Table 2):

(Refer to IS 12234 Table 2 for exact values)

Summary:

• Use safe, non-toxic materials.
• Limit rework to 15% except valve seats.
• Follow acceptance sampling for quality control.

flowchart TD
    A[Raw Materials] --> B[Manufacturing]
    B --> C{Rework?}
    C -->|Yes, ≤15%| D[Allowed]
    C -->|Valve Seat| E[No Rework Allowed]
    B --> F[Final Inspection]
    F --> G{Defects ≤ Acceptance Number?}
    G -->|Yes| H[Lot Accepted]
    G -->|No| I[Lot Rejected]

IS 12234 – Performance Tests Key Points

1. Endurance Test (Clause 7.4 & Appendix C)

• Purpose: Verify durability and reliable operation under repeated cycles.
• Test Procedure:
  • Operate the valve through a specified number of cycles (as per Appendix C).
  • Check for wear, leakage, and functional integrity.
• Acceptance Criteria: No significant leakage or mechanical failure after cycles.

2. Number of Tests and Conformity Criteria (Clause 8.2)

• Sampling: Tests performed on samples from production batches.
• Criteria: Test results must meet specified performance parameters (e.g., leakage limits, pressure ratings).

3. Back Nut Specifications (Clause 6.10)

• Threads: Parallel internal threads per IS 2643 (Part 3)-1975.
• Size: Same as float valve for compatibility.

Typical Endurance Test Parameters (from IS 12234 Appendix C):

flowchart LR
    A[Start Endurance Test] --> B[Operate Valve Cycles]
    B --> C{Leakage?}
    C -- No --> D[Check Mechanical Integrity]
    D --> E{Pass Criteria?}
    E -- Yes --> F[Test Passed]
    E -- No --> G[Reject Valve]
    C -- Yes --> G

For detailed values and procedures, refer to Appendix C of IS 12234 and IS 2643 Part 3 for thread specs.

IS 12234 - Number of Tests and Criteria for Conformity (Clause 8.2)

Sampling and Acceptance Criteria (Table 2)

Key Points:

• Sample size depends on the lot size (Clause 8.1.3).
• The lot is accepted if the number of defective items ≤ acceptance number (Clause 8.2.2).
• If defects exceed acceptance number, the lot is rejected.
• Endurance tests per Appendix C (Clause 7.4.1) may apply for quality verification.

Summary Formula for Acceptance:

[ \text{Accept Lot if } D \leq A ]

• (D) = Number of defective items in sample
• (A) = Acceptance number from Table 2

This ensures quality control by statistically sampling valves from production lots.

IS 12234 - Marking & Sampling Key Points

Marking (Clause 9.2)

• Valves may be marked with the BIS Standard Mark.
• The Standard Mark certifies compliance with IS 12234 under BIS supervision.
• Use of the Standard Mark is governed by the BIS Act, 1986.
• Licensing conditions for the Standard Mark are available from BIS.

Sampling & Testing (Clauses 7.2.1, 8.2, 8.2.2)

• Random Sampling Method: Refer to Appendix A (Clause 7.2.1) for detailed procedures.
• Acceptance Criteria:
  • Sample a lot as per prescribed sample size.
  • Lot is accepted if defective items ≤ acceptance number from Table 2.

Table 2: Acceptance Number Summary (Example)

(Exact values in IS 12234 Table 2)

Summary Diagram: Marking & Sampling Flow

flowchart TD
    A[Start: Valve Production] --> B{Marking}
    B -- Yes --> C[Apply BIS Standard Mark]
    B -- No --> D[No Marking]
    C --> E[Random Sampling per Appendix A]
    D --> E
    E --> F[Perform Tests]
    F --> G{Defective Items ≤ Acceptance Number?}
    G -- Yes --> H[Lot Accepted]
    G -- No --> I[Lot Rejected]

For detailed acceptance numbers and sampling plans, always refer to IS 12234 Table 2 and Appendix A.

IS 12234 – Antisiphonage Test Key Points

Test Setup (Clause 1.5 & Fig. 3)

• Apparatus:
  • (a) Mild steel cylinder connected to vacuum pump/injector
  • (b), (c) Vacuum gauge (0–0.1 MPa / 0–762 mm Hg)
  • (g) Close valve, (j) Open valve
  • (e) Catchpot to detect back siphonage
  • (k) Valve under test
  • (0) Cistern with water level maintained at 1.5 ± 0.1 m above valve inlet center

Test Procedure (Clause 7.2.1 & Appendix A)

• Close valve (g), open valve (j)
• Maintain vacuum while water level in cistern is kept at 1.5 m ± 0.1 m
• Duration: 180 seconds
• Observe catchpot (e) for water presence — no water indicates no back siphonage
• This is a type test for float valves

Important Specifications

Interpretation

• No water in catchpot: Valve passes antisiphonage test
• Water detected: Valve fails, indicating back siphonage risk

flowchart LR
    A[Cistern with water (1.5m height)] -->|Water inlet| K[Valve under test (k)]
    K --> E[Catchpot (e)]
    E --> G[Close valve (g)]
    J[Open valve (j)] --> E
    B[Vaccum gauge (b,c)] --> A
    A --> VacuumPump[Vacuum Pump/Injector]

This ensures the valve prevents backflow under vacuum conditions per IS 12234.

IS 12234: Flow Test Key Points and Procedure

Setup (Clause 7.3.1, Appendix B)

• Container A: Water level maintained at 1.5 ± 0.1 m above valve inlet center.
• Cistern B: Conforms to IS 7231-1984 (plastic flushing cistern).
• Connecting tube: 15 mm bore between container A and cistern B.
• Test duration: 180 seconds (3 minutes).

Procedure (Clauses 1.5, B-2, B-3)

1. Maintain water level in container A at specified height.
2. Allow float valve to discharge water into cistern B for 180 seconds.
3. At test end, measure volume of water collected in cistern B.

Key Formula

• Flow rate, Q = V / t

Where:

• Q = flow rate (liters/second)
• V = volume collected in cistern B (liters)
• t = test duration (seconds, 180 s)

Summary Table

flowchart LR
    A[Container A: Water level 1.5m] -->|Water flow| B[Cistern B (IS 7231)]
    B -->|Volume measured after 180s| M[Measurement]

This test ensures the float valve's flow capacity and shut-off performance per IS 12234.

IS 12234 - Endurance Test Summary (Clause 7.4 & Appendix G)

• Purpose: Verify float valve durability over repeated operation.
• Requirement: Complete 200,000 cycles without failure.
• Post-Test: Valve must pass hydraulic and shut-off tests (Clause 7.1).

Key Points:

• Test Type: Type test (one valve per design/type).
• Cycle Definition: One full opening and closing operation.
• Acceptance Criteria:
  • No leakage during shut-off test.
  • Hydraulic performance as per original specifications.

Typical Endurance Test Procedure (Appendix G):

1. Set valve in test rig simulating operating conditions.
2. Operate valve continuously for 200,000 cycles.
3. Inspect for wear, leakage, and operational integrity.
4. Conduct hydraulic and shut-off tests post endurance cycles.

Summary Table:

flowchart LR
    A[Start Endurance Test] --> B{Complete 200,000 Cycles?}
    B -- No --> A
    B -- Yes --> C[Conduct Hydraulic & Shut-off Tests]
    C --> D{Pass Tests?}
    D -- Yes --> E[Valve Approved]
    D -- No --> F[Valve Rejected]

This ensures valve reliability and compliance with IS 12234 standards.