delivery valve for centrifugal fire pump outlets 1986 Edition
This standard outlines the specifications for delivery valves installed on centrifugal fire pump outlets, focusing on the conventional screw-down valve design used to regulate water flow during firefighting. It ensures these valves meet stringent criteria regarding materials, construction, and performance to guarantee dependable sealing and longevity. The guideline is crucial for professionals involved in manufacturing, supplying, and engineering fire protection equipment.
This standard outlines the specifications for delivery valves installed on centrifugal fire pump outlets, focusing on the conventional screw-down valve design used to regulate water flow during firefighting. It ensures these valves meet stringent criteria regarding materials, construction, and performance to guarantee dependable sealing and longevity. The guideline is crucial for professionals involved in manufacturing, supplying, and engineering fire protection equipment.
Audience
Who Uses This Standard
Fire protection system engineers
Manufacturers of fire pumps
Inspectors of fire safety equipment
Designers of hydraulic systems
Quality assurance specialists
Municipal firefighting authorities
Industrial safety supervisors
Contents
Key Topics Covered
✓Components of valve assemblies
✓Material requirements for valve bodies and spindles
✓Specifications for valve body and handwheel materials
✓Standards for instantaneous female outlets and blank caps
✓Surface treatment and casting quality standards
✓Hydrostatic pressure and leakage testing procedures
✓Marking protocols and ISI certification guidelines
✓Painting and finishing standards
✓Threading specifications for valve spindles
✓Inspection criteria and conformity assessments
✓Materials for gland packing and sealing
✓Dimensional and geometric requirements of valve assemblies
Structure
Table of Contents
1Scope and General Requirements▼
Overview of Scope and Essential Provisions
Scope: Pertains to water fittings specifically designed for firefighting applications.
Dimensional Units: All measurements are specified in millimetres (see Clause 12.5).
Rounding Procedures: Testing outcomes should be rounded following IS 2:1960 guidelines (Clause 6).
Material Compliance: Outlets and caps must adhere to IS 5290-1983 standards (Clause 3.6).
Conformity Checks: Each valve must satisfy the criteria outlined in Clause 8.1 (refer Table 8).
Referenced Standards: Includes specifications for materials such as leaded tin bronze, aluminium alloys, brass, stainless steel, washers, hydraulic leather, asbestos packing, phosphor bronze wires, among others.
2Delivery Valve Assembly Details▼
Specifications for Delivery Valve Assemblies in Centrifugal Fire Pumps
Main Components:
Valve body, instantaneous female outlet, and blank cap as per Clause 2.1.
Dimensions conform to Fig. 1 (Clause 4.1) with units in millimetres (Clause 12.5).
The valve follows a screw-down design as illustrated in Fig. 1.
Typical Dimensional Data (from Fig. 1):
Component
Dimension (mm)
Remarks
Valve Body Diameter
See Fig. 1
Must fit pump outlet properly
Outlet Size
Standard instantaneous female coupling
Compatible with fire hose connectors
Blank Cap
Sized to fit outlet
Used for sealing when valve is not active
Notes:
The assembly must enable swift operation and provide a leak-tight seal.
Materials should be robust enough for firefighting conditions.
Dimensions must strictly match Fig. 1 to ensure interchangeability.
3Material Specifications▼
Material Requirements and References for IS 4928
Materials Included:
Leaded tin bronze ingots and castings as per IS 5290-1983
Aluminium and aluminium alloy ingots and castings for general engineering
High tensile brass rods and sections (excluding forging stocks)
Free-cutting brass bars and rods
Stainless steel bars and flats
Washers for firefighting water fittings
Vegetable-tanned hydraulic leather
Asbestos gland packing
Phosphor bronze wires
Landing valves
Units: All dimensions are expressed in millimetres (Clause 12.5).
Rounding: Test and analysis results must conform to rounding rules in IS 2-1960 to keep consistent significant figures.
Example Material Properties (Leaded Tin Bronze):
Property
Typical Value
Tensile Strength
350–450 MPa
Brinell Hardness
80–120 HB
Density
Approx. 8.7 g/cm³
Melting Point
900–1000 °C
For further mechanical and chemical data, consult the respective Indian Standards cited.
4Valve Dimensions and Form▼
Specifications for Dimensions and Shape of Screw-Down Delivery Valves
Measurement Units: All dimensions in millimetres (mm) (Clause 12.5).
Design and Dimensions: Must conform to the shape and sizes depicted in Fig. 1 (Clause 4.1).
Outlet and Cap Standards: Instantaneous female outlet and blank cap must meet IS 5290-1983 (Clause 3.6).
Rounding: Final test values rounded according to IS 2-1960, maintaining the significant digits specified (Clause 0.3).
Typical Dimensions from Fig. 1:
Part
Dimension (mm)
Notes
Overall Length
Refer to Fig. 1
Full valve assembly length
Valve Body Diameter
Refer to Fig. 1
Standardized valve body size
Outlet Size
As per IS 5290
Instantaneous female outlet size
Thread Size
As per Fig. 1
Screw-down thread specification
This ensures uniform sizing and compatibility for firefighting water fittings.
5Manufacturing Specifications▼
Manufacturing Guidelines and Requirements
All dimensional measurements must be in millimetres (Clause 12.5).
Female outlet and blank cap must comply with IS 5290-1983 (Clause 3.6).
Materials include leaded tin bronze, aluminium alloys, high tensile brass, stainless steel bars, and others as per referenced IS codes.
Test results should be rounded off following IS 2-1960 (Clause 6).
Each valve must fulfill the conformity criteria listed in Clause 8.1 Table 8.
Paints and enamels used must adhere to IS-approved color standards (third revision).
Delivery valve design details are standardized per Fig. 1.
Manufacturing Process Highlights:
Raw material inspection,
Dimensional verification,
Surface finishing and painting,
Functional and leak-tightness testing,
Final inspection and marking before dispatch.
6Testing Protocols▼
Key Testing Procedures and Requirements
Rounding Off (Clause 0.3): Test or analysis values must be rounded according to IS 2-1960, preserving the number of significant figures matching the standard.
Measurement Units (Clause 12.5): Dimensions are in millimetres (mm).
Performance Standards (Clause 3.6): Instantaneous female outlet and blank cap must conform to IS 5290-1983.
Conformity (Clause 8.1): Each valve unit must be individually tested for compliance.
Typical Tests Include:
Parameter
Standard/Method
Notes
Dimensional Accuracy
Millimetres (Clause 12.5)
As per design specifications
Visual Inspection
Surface finish and defect checks
No cracks or deformities
Pressure Testing
Hydrostatic or pneumatic tests
Tested at specified pressures
Material Verification
Referenced IS standards
Ensures material compliance
Functional Testing
Valve operation and leak tests
Must operate smoothly without leaks
This testing regime ensures reliability and safety in firefighting operations.
7Marking and Identification▼
Marking Requirements and Certification Guidelines
Valves may bear the ISI Certification Mark as evidence of compliance and ongoing quality control (Clause 7.1.1).
Markings must include manufacturer identification and year of production.
Dimensions related to marking are in millimetres (Clause 12.5).
Rounding of marking-related values must follow IS 2:1960 (Clause 6).
Markings must be consistent with standards such as IS 5290-1983 for outlets and caps.
Significance of ISI Mark:
Demonstrates compliance with Indian Standards.
Indicates products are subject to continuous inspection by ISI.
Provides assurance of product quality and traceability.
8Conformity and Compliance Criteria▼
Summary of Conformity Requirements (Clause 8)
Every valve must be verified against all standard requirements to confirm compliance.
Test results shall be rounded as per IS 2:1960, maintaining the same significant digits as the specification.
All dimensions expressed in millimetres (Clause 12.5).
Valves may carry the ISI Certification Mark to signify adherence under ISI’s quality control and inspection system.
ISI performs continuous monitoring to ensure ongoing conformity.
Rounding Rules per IS 2:1960:
If the digit following the last significant figure is less than 5, round down.
If it is 5 or greater, round up.
The number of significant figures remains consistent with the specified value.
This process ensures high quality and uniformity in fire protection valve manufacturing.
Frequently Asked
Popular Questions About IS 4928
?Which materials are prescribed for the valve body and spindle according to IS 4928?▼
Materials Specified for Valve Body and Spindle in IS 4928:
Valve Body, Gland Nut, and Bush (Clause 3.1):
Leaded tin bronze (Grade LTB-2, IS: 318-1981)
Aluminium alloy (IS designations 4600, 4450, or 4225 as per IS: 617-1975)
Valve Spindle (Clause 3.2):
Brass rod conforming to IS: 320-1980 or IS: 319-1974 for valves with leaded tin bronze bodies
Stainless steel per IS: 6603-1972 when paired with aluminium alloy or leaded tin bronze bodies
Handwheel (Clause 3.3):
Leaded tin bronze Grade LTB-2 for gunmetal body valves
Aluminium alloys (IS 4450, 4225, or 4600) for aluminium alloy body valves
Summary Table:
Component
Material Specification
IS Reference
Valve Body
Leaded tin bronze (LTB-2) or Aluminium alloy
IS: 318-1981, IS: 617-1975
Valve Spindle
Brass rod or Stainless steel
IS: 320-1980, IS: 319-1974, IS: 6603-1972
Handwheel
Leaded tin bronze or Aluminium alloy
IS: 318-1981, IS: 617-1975
These materials ensure compatibility and durability tailored to the valve body type.
?What methods are used to test the delivery valve for water tightness and pressure?▼
Water Tightness and Pressure Testing Procedures for Delivery Valves:
Hydrostatic Pressure Test:
Apply pressure of 2.1 MN/m² (21 kgf/cm²) with the valve handwheel open for 2½ minutes.
Confirm absence of leakage through the valve body and spindle gland.
Closed Valve Test:
Fully close the handwheel.
Repeat hydrostatic test under same pressure and duration.
Verify no leakage through the flap valve seat.
Test Summary:
Test Condition
Pressure
Duration
Leakage Allowed?
Valve Open
2.1 MN/m² (21 kgf/cm²)
2½ minutes
No leakage
Valve Closed
2.1 MN/m² (21 kgf/cm²)
2½ minutes
No leakage through flap seat
These tests ensure the valve is free from porosity and provides a leak-proof seal under operating pressures.
?Does IS 4928 include specifications for quick closing clack valves or only for screw down valves?▼
IS 4928 (1986 edition) exclusively covers ordinary screw down delivery valves for centrifugal fire pump outlets.
The earlier 1968 version included quick closing clack valves.
Experience showed quick closing clack valves were unsuitable for fire pump applications.
Consequently, the 1986 revision removed quick closing clack valves from the scope.
The standard title and clauses were revised accordingly.
Separate standards are being developed for ball valve types used on crash tenders.
Summary Table:
Valve Type
Covered in IS 4928 (1986)?
Quick Closing Clack Valve
No
Ordinary Screw Down Valve
Yes
Ball Valve (Crash Tender)
No (separate standard)
Therefore, IS 4928 should be referenced only for screw down valve applications on fire pump outlets.
?What are the marking and certification rules for valves under IS 4928?▼
Marking and Certification Requirements per IS 4928:
Permanent Marking (Clause 7.1):
Manufacturer’s name and/or brand
Year of manufacture
ISI Certification Mark (Clause 7.1.1):
Marking with the ISI certification symbol is optional.
The ISI mark signifies compliance with IS 4928 and ongoing inspection by ISI.
Usage is regulated by the Indian Standards Institution (Certification Marks) Act.