delivery valve for centrifugal fire pump outlets

IS 4928: Scope - Key Specifications & Notes

• Scope: Covers water fittings for fire fighting purposes.
• Dimensions: All dimensions are in millimetres (Clause 12.5).
• Performance: Test results shall be rounded off as per IS 2:1960 (Clause 6).
• Materials: Outlets and caps conform to IS 5290-1983 (Clause 3.6).
• Conformity: Each unit must meet the criteria specified in Clause 8.1 (Table 8).
• Applicable Standards: Includes specifications for various materials like leaded tin bronze, aluminium alloys, brass, stainless steel, washers, hydraulic leather, asbestos packing, phosphor bronze wires, etc.

Rounding Off Formula (IS 2:1960)

For a value ( V ) and specified significant figures ( n ):

[ \text{Rounded value} = \text{Round}\left(V, n\right) ]

where rounding is done to the same number of significant digits as the specified value.

Summary Table: Material Specifications Reference

If you need details on specific fittings or performance criteria, please specify.

IS 4928: Delivery Valve Assembly for Centrifugal Fire Pumps

Key Specifications:

• Components: Valve body, instantaneous female outlet, and blank cap (Clause 2.1).
• Dimensions: As per Fig. 1 (Clause 4.1), all in millimeters (Clause 12.5).
• Type: Screw down type delivery valve (Fig. 1).

Typical Dimensions (from Fig. 1):

Important Notes:

• The delivery valve assembly must ensure quick operation and tight sealing.
• Materials should withstand fire service conditions.
• Dimensions must strictly follow Fig. 1 to ensure interchangeability.

flowchart LR
    A[Valve Body] --> B[Instantaneous Female Outlet]
    B --> C[Blank Cap]
    C -->|Seals| A

This assembly ensures controlled water delivery and quick connection to fire hoses. For detailed dimensions, refer to Fig. 1 in IS 4928.

IS 4928: Materials Key Specifications & References

• Materials Covered:

  • Leaded tin bronze ingots & castings — IS 5290-1983
  • Aluminium & aluminium alloy ingots & castings — General engineering
  • High tensile brass rods & sections (excluding forging stocks)
  • Free-cutting brass bars, rods & sections
  • Stainless steel bars & flats
  • Washers for firefighting water fittings
  • Vegetable tanned hydraulic leather
  • Gland packing asbestos
  • Phosphor bronze wires
  • Landing valves

• Units: All dimensions in millimetres (Clause 12.5)

• Rounding Off: Final test or analysis results must be rounded as per IS 2-1960, keeping significant figures consistent with specified values.

Typical Material Properties (Example: Leaded Tin Bronze)

Summary Diagram: Material Specification Flow

flowchart LR
    A[IS 4928 Materials] --> B[Bronze (IS 5290)]
    A --> C[Aluminium Alloys]
    A --> D[Brass Rods & Sections]
    A --> E[Stainless Steel Flats]
    A --> F[Washers & Leather]
    A --> G[Asbestos Packing]
    A --> H[Phosphor Bronze Wires]
    A --> I[Landing Valves]

For detailed mechanical properties and chemical compositions, refer to the respective IS codes cited above.

IS 4928: Dimensions and Shape of Delivery Valve (Screw Down Type)

• Units: All dimensions are in millimetres (mm) (Clause 12.5).
• Shape & Dimensions: As per Fig. 1 (Clause 4.1), the delivery valve assembly must follow the typical shape and essential dimensions shown.
• Outlet & Cap: The instantaneous female outlet and blank cap must conform to IS 5290-1983 (Clause 3.6).
• Rounding Off: Final test values must be rounded as per IS 2-1960, retaining the same number of significant digits as the specified value (Clause 0.3).

Summary Table (Typical Dimensions from Fig. 1)

Note: For precise dimensions, refer to Fig. 1 of IS 4928 and IS 5290 for outlet specifications.

flowchart LR
    A[Delivery Valve Assembly] --> B[Valve Body Dimensions]
    A --> C[Instantaneous Female Outlet]
    C --> D[Conforms to IS 5290-1983]
    B --> E[Dimensions as per Fig. 1]

This ensures standardized sizing for compatibility and performance in firefighting water fittings.

IS 4928 - Manufacturing Requirements Summary

• Dimensions: All dimensions must be in millimetres (Clause 12.5).

• Material Specifications:

  • Female outlet and blank cap must conform to IS:5290-1983 (Clause 3.6).
  • Materials include leaded tin bronze, aluminium alloys, high tensile brass, stainless steel bars, etc., as per referenced IS standards.

• Performance & Testing:

  • Test results must be rounded off per IS:2-1960 (Clause 6).
  • Each unit must meet criteria in Clause 8.1 Table 8 (Criteria for Conformity).

• Manufacturing Controls:

  • Paints and enamels must follow IS color codes (third revision).
  • Delivery valve screw down type details are standardized (Fig. 1).

Key Notes on Rounding (IS:2-1960)

• Round off test values to the same significant figures as specified values.
• Example: If specified tolerance is 0.3 mm, round measured values to 1 decimal place.

Typical Manufacturing Checklist (per Clause 8.1)

flowchart TD
    A[Raw Material Inspection] --> B[Manufacturing Process]
    B --> C[Dimension Check (mm)]
    C --> D[Surface Treatment & Painting]
    D --> E[Functional Testing]
    E --> F[Final Inspection & Marking]
    F --> G[Dispatch]

For detailed dimensions and material specs, refer to IS 4928 Clauses 3, 6, 8, and 12.5.

IS 4928 - Testing Key Points

• Rounding Off (Clause 0.3):
  Final test or analysis values must be rounded per IS 2-1960, retaining the same significant figures as the specified standard value.

• Units (Clause 12.5):
  All dimensions are expressed in millimetres (mm).

• Performance Requirements (Clause 3.6):
  Instantaneous female outlet and blank cap must comply with IS 5290-1983.

• Conformity Criteria (Clause 8.1):
  Every unit must be individually checked against the standard's requirements.

Common Testing Specifications (General Practice)

Rounding Off Example (IS 2-1960)

If specified value = 12.5 (3 significant digits), test result = 12.487 → rounded to 12.5.

flowchart TD
    A[Test or Analysis] --> B{Compare with Standard}
    B -->|Meets Criteria| C[Accept Unit]
    B -->|Fails Criteria| D[Reject Unit]
    C --> E[Round Off Result (IS 2-1960)]
    E --> F[Report Compliance]

For detailed test procedures, refer to the full IS 4928 text and related IS codes (e.g., IS 5290).

IS 4928 - Marking Key Points

• Clause 7.1.1: Valve assemblies may be marked with the ISI Certification Mark indicating compliance with IS standards, quality control, and continuous inspection by ISI.

• Marking Dimensions: All dimensions for marking details are in millimetres (Clause 12.5).

• Rounding Off: Test results or calculated values for marking must be rounded off as per IS 2:1960 to the same significant figures as specified (Clause 6).

• Reference Standards: Marking must ensure conformity with related standards such as IS 5290-1983 for outlets and blank caps (Clause 3.6).

ISI Marking Significance

• Indicates product compliance under ISI supervision.
• License for ISI mark governed by Indian Standards Institution rules.
• Ensures product quality and continuous conformity checks.

Summary Table: Marking Specifications

flowchart TD
    A[Valve Assembly] --> B{Marking}
    B --> C[Dimensions in mm]
    B --> D[ISI Certification Mark]
    B --> E[Rounding as per IS 2:1960]
    B --> F[Conformity to IS 5290-1983]

This concise summary covers marking requirements and related specifications per IS 4928.

IS 4928 - Clause 8: Criteria for Conformity (Summary)

• Each unit shall be checked against all requirements specified in the standard to ensure compliance.
• Final test results must be rounded off as per IS 2:1960 rules, retaining the same number of significant digits as the specified values.
• Dimensions are expressed in millimetres (Clause 12.5).
• Valve assemblies may bear the ISI Certification Mark (Clause 7.1.1), indicating compliance under ISI's quality control and inspection system.
• Continuous monitoring by ISI ensures ongoing conformity of ISI-marked products.

Important Notes:

Rounding off as per IS 2:1960

• If the digit after the last significant figure is <5, round down.
• If the digit is ≥5, round up.
• Keep the number of significant figures equal to the standard's specified value.

flowchart TD
    A[Unit Manufactured] --> B[Testing as per IS 4928]
    B --> C{Meets Criteria?}
    C -- Yes --> D[Apply ISI Mark (Optional)]
    C -- No --> E[Reject/Rectify Unit]
    D --> F[Product Released]
    E --> F

This ensures quality and conformity for fire fighting water fittings under IS 4928.