Water Meters (Bulk Type)

IS 2373: Scope & Key Specifications for Water Meters

Scope (Clause 4.12.1)

• Defines ranges of registration for water meters based on nominal size.
• Registration ranges ensure meter accuracy over expected flow volumes.

Key Tables:

(Table 2: Ranges of Registration)

Capacity Ratings (Table 4)

Minimum Starting Flows (Table 5)

IS 2373: Definitions & Key Specifications

Key Definitions (Clause 2.0)

• Thickness of flange
• Diameter of bolt circle (C)
• Number of holes (A)
• Diameter of bolt holes (d)
• Diameter of bolts

(Refer Fig. 1 & 2 in IS 2373 for visual details)

Important Tables

1. Capacity Ratings for Water Meters (Clause 5.3.2)

2. Minimum Starting Flows (L/hr)

IS 2373: Nominal Size of Water Meters

Key Specifications (Clause 3.1)

Thickness & Bolt Details (Clause 3.0)

• Thickness of flange, diameter of bolt circle (C), number of holes (A), diameter of bolt holes (d), and diameter of bolts are specified for each nominal size (refer to detailed tables in the code).

Registration Ranges (Table 2, Clause 4.12.1)

Notes:

• Nominal size refers to the standard diameter of the meter's inlet/outlet.
• The ranges of registration ensure accuracy in measuring flow volumes.
• Flange and bolt specifications ensure proper mounting and sealing.

flowchart LR
    A[Nominal Size] --> B[Physical Dimensions]
    A --> C[Registration Range]
    B --> D[Flange Thickness & Bolt Details]
    C --> E[Min & Max Registration Volumes]

For detailed flange and bolt dimensions, refer to Clause 3.0 tables in IS 2373.

IS 2373: Materials and Construction Key Points

1. Materials for Screws, Studs, and Nuts (Clause 4.4)

• Materials: Mild steel (IS:280-1978), Brass (IS:320-1962), or corrosion-resistant materials.
• For water contact: Use brass (IS:320-1962) or stainless steel (07 Cr 18 Ni 9, IS:1570 Part V-1972).

2. Flange Dimensions for 50 mm Nominal Size Water Meter (Table 1, Clause 4.4)

3. Ranges of Registration of Water Meters (Table 2, Clause 4.12.1)

Summary

• Use specified materials for corrosion resistance and strength.
• Follow flange dimensions strictly for compatibility.
• Select water meter registration ranges as per nominal size for accuracy.

flowchart TD
    A[Materials for Fasteners] -->|Mild Steel, Brass, Stainless Steel| B[Suitable for Water Contact]
    B --> C[Flange Dimensions]
    C --> D[Outside Diameter, Thickness, Bolt Circle, Holes]
    D --> E[Water Meter Registration Ranges]

For detailed design, refer to IS 2373 clauses and referenced IS standards.

IS 2373: Performance Requirements for Water Meters

Key Performance Tests (Clause 8.3)

• Hydrostatic Test (Clause 5.2)
• Tests to determine:
  • Capacity ratings
  • Minimum starting flows

Capacity Ratings (Litres per Hour)

Minimum Starting Flows (Litres per Hour) (Table 5)

IS 2373: Frost Protection for Water Meters

Key Specifications (Clause 6.1 & 6.2)

• Meters prone to frost damage must have frost protection devices.
• Typical devices:
  • Rubber pads that accommodate water expansion on freezing.
  • Collapsible metal rings or discs that allow pressure relief by lifting or yielding, preventing damage.
• Damaged frost protection devices require immediate replacement to avoid supply disruption or wastage.
• Purchaser must specify frost protection requirement at order (Clause 6.2).

Relevant Tables from IS 2373

IS 2373 - Marking Specifications for Water Meters

Key Tables & Specifications:

1. Capacity Ratings for Intermediate Flows (Litres/hour)

2. Minimum Starting Flows (Litres/hour)

3. Ranges of Registration (Litres)

IS 2373 - Testing Key Points

1. Classification of Tests (Clause 8.1)

• Production Routine Tests
• Type Tests
• Acceptance Tests

2. Samples for Tests (Clause 8.2)

• Samples are taken from production or stock.
• For Type Tests (Clause 8.2.1):
  • 50 mm size: 2 meters
  • 80 mm and above: 1 meter
• Samples must be accompanied by:
  • 4 copies of manufacturer's detailed specs
  • Loss of head and accuracy curves

3. Production Routine Tests (Clause 8.3)

• Hydrostatic Test (see Clause 5.2)
• Performance tests to verify:
  • Accuracy
  • Loss of head
  • Other operational parameters as per manufacturer's specs

4. Hydrostatic Test (Clause 5.2) - Summary

• Apply pressure (usually 1.5 times working pressure)
• Hold for a specified duration (e.g., 2 minutes)
• Check for leaks or permanent deformation

Typical Test Parameters Table

flowchart LR
    A[Start Testing] --> B{Test Type}
    B -->|Type Test| C[Send samples to authority]
    B -->|Production Routine| D[Hydrostatic + Performance Tests]
    B -->|Acceptance| E[Verify as per Type Test]
    C --> F[Check Accuracy & Loss of Head]
    D --> F
    E --> F
    F --> G[Pass/Fail Decision]

This concise summary aligns with IS 2373 testing clauses and ensures compliance with sample sizes, test types, and performance criteria.

IS 2373: Information to be Supplied by Purchaser

Per Appendix A (Clause 4.1), the purchaser must provide the following details with enquiry/order:

• Nominal size of meter (e.g., 50 mm, 80 mm, etc.)
• Type of meter: vane-wheel or helical
• Provision for locking: required or not
• Type of counter:
  1. Circular multipointer pattern
  2. Straight reading cyclometer type
  3. Combination of pointer and counter
• Frost protection device: required or not
• Strainer: required or not
• Wiper: required or not
• Dial type: wet or dry

Key Table: Ranges of Registration (Clause 4.12.1, Table 2)

Notes:

• Acceptance Tests (Clause 8.2.2): Number of samples to be mutually agreed.
• Type Test Reports (Clause 8.4.2.1): Use format in Appendix C.
• Headloss Determination: See Appendix B (Clause 5.3.3) for method.

This ensures purchaser's requirements are clear for manufacturing and testing compliance.

IS 2373: Method for Measurement of Headloss in Water Meters

Key Points from IS 2373 (Clause 5.3.3 & Appendix B):

• Headloss Measurement Setup (Fig. 3):

  • Use a calibrated tank supplying water through a pump or overhead tank.
  • Measure pressure drop across the meter using pressure taps connected to manometers.
  • Measure discharge using:
    • Water meter (WM) itself, or
    • Other devices like orifice meter, venturi meter, or notches.

• Procedure:

  • At specified flow rates (Clause 5.3.1 & 5.3.2), note the pressure drop (ΔP).

  • Convert pressure drop to headloss (h) using:

    [ h = \frac{\Delta P}{\rho g} ]

    where:

    • ( \Delta P ) = pressure difference (Pa)
    • ( \rho ) = density of water (~1000 kg/m³)
    • ( g ) = acceleration due to gravity (9.81 m/s²)

• Typical Flow Rates:

  • Nominal capacity and intermediate flows as per Clauses 5.3.1 & 5.3.2.

Summary Table: Headloss Calculation

Typical Arrangement (Fig. 3) - Mermaid Diagram

flowchart LR
    A[Calibrated Tank] --> B[Regulating Valve (RV)]
    B --> C[Water Meter (WM)]
    C --> D[Discharge Measurement Device]
    C --> E[Pressure Taps for Manometer]
    E --> F[Manometer]

Additional Notes:

• Report results as per Appendix C.
• Provide purchaser info per **Append