Specification for Underground Fire Hydrant, Sluice Valve Type
1992 Edition

Overview of Scope - IS 909

• Defines construction, dimensions, and materials for underground sluice valve fire hydrants.
• Specifies outlet thread types, caps, chains, and surface box details.
• Applies rounding rules as per IS 2:1960.
• Lists related standards in Annex A.

Key Material and Component Specifications:

Dimensional and Thread Specifications:

• Outlet features external rounded threads: 2 threads per 2.54 cm (~8 TPI), per IS 4694.
• Tolerances:
  • ±2 mm for dimensions ≤ 15 mm
  • ±2 mm for 16–50 mm
  • ±5 mm for > 50 mm
• Surface box minimum mass: 135 kg, as illustrated in Figure 2.

Construction Details:

• Outlet cap fully covers threads and is secured by a steel chain (minimum 3 mm diameter).
• Castings must be free of burrs and defects.
• Bolts and nuts comply with IS 1367 (Part 14).

flowchart LR
  Body[Body (Cast Iron)] --> ValveSeat[Valve Seat (Gun Metal)]
  ValveSeat --> Valve[Valve (Gun Metal)]
  Valve --> Spindle[Spindle (Brass)]
  Spindle --> SpindleNut[Spindle Nut (Gun Metal)]
  Body --> Outlet[Outlet with External Thread]
  Outlet --> Cap[Cap attached by Chain]
  Body --> DrainBolt[Drain Bolt (Mild Steel)]

For comprehensive details, refer to clauses 2.54 and 4.6 of IS 909.

Thread Thickness Specification (Clause 5.7)

• Nominal thread thickness (t): 5.7 mm with tolerance +0 / -0.4 mm.

Thread Dimension Details (Clause 6.8)

• Crest diameter: 82 - 2 mm with no positive tolerance.
• Maximum root diameter: 68.0 mm.

Thread Type and Pitch (Clause 2.54)

• External rounded threads.
• Pitch: 2 threads per 2.54 cm (1 inch), equivalent to 12.7 mm per thread.
• Taper angle: 1 in 20 on each side, per Figure 1A.
• Threads conform to IS 4694 with 32 × 6 mm pitch.

Additional Information

• Caps fully cover outlet threads and are connected by steel chains at least 3 mm in diameter to prevent loss.
• All components must be free from burrs and imperfections.
• Dimensional tolerances as per IS 2102:1962:
  • ±2 mm for dimensions up to 15 mm.
  • ±2 mm for 16 to 50 mm.
  • ±5 mm for dimensions exceeding 51 mm.

Summary Table of Thread Dimensions

Would you like a mermaid diagram illustrating the thread profile and dimensions?

Summary of General Provisions in IS 909

1. Rounding Practices (IS 2:1960):

   • All final test and calculation results must be rounded according to IS 2 guidelines.
   • The number of significant digits should match the standard's specified values.

2. Hydrant Outlet Threads (Clause 2.54 & Figure 3):

   • External rounded threads with density of 2 threads per 2.54 cm (~8 TPI).
   • Thread specifications follow IS 4694: 32 × 6 mm pitch.
   • Outlet cap covers threads and is secured with a steel chain of at least 3 mm diameter, treated against corrosion.

3. Materials for Hydrant Parts:

4. Dimensional Tolerances (IS 2102:1962):

   • ±2 mm for sizes ≤ 15 mm.
   • ±2 mm for 16–50 mm.
   • ±5 mm for sizes > 50 mm.

5. Construction Notes:

   • All parts must be clean castings without burrs, welding, or repairs.
   • Flanged connections use bolts and nuts.
   • Caps are non-threaded and fit securely.

flowchart TD
  Body[Hydrant Body (C.I.)] --> ValveSeat[Valve Seat (G.M.)]
  ValveSeat --> Valve[Valve (G.M.)]
  Valve --> Spindle[Spindle (Brass)]
  Spindle --> Outlet[Outlet with External Thread (IS 4694)]
  Outlet --> Cap[Cap secured by Steel Chain]

This section covers the overarching requirements for design and quality.

Materials Specification According to IS 909

Thread Details for Outlet:

• External rounded thread with 2 threads per 2.54 cm (1 inch).
• Thread size example: 32 × 6 mm pitch, per IS 4694.
• Cap designed to fully cover threads and prevent contamination.

Road Surface Box Specifications as per IS 909

• Material and Minimum Weight:

  • Fabricated from Cast Iron as per IS 210-1978 FG-200.
  • Minimum weight requirement: 135 kg.

• Dimensions and Construction (Referencing Figure 2):

  • Flanged to fit reducer flange.
  • Cap is non-threaded with feather edges removed for safety.
  • Cover embossed with "FH" and finished with canary yellow paint (IS 5:1978, shade 309).
  • Entire hydrant painted fire red (IS 5:1978, shade 536).

• Bolts and Nuts:

  • Made from carbon steel conforming to IS 1367 (Part 14):1984.

• Outlet Specifications:

  • Screwed type with external rounded threads (2 threads per 2.54 cm) per IS 4694.
  • Outlet cap secured by steel chain (minimum 3 mm diameter), treated against corrosion.

• Tolerance Guidelines (per IS 2102:1962):

• Material Reference Table:

Diagram: Road Surface Box Components

graph TD
  SurfaceBox[Road Surface Box Body (Cast Iron)] --> Flange[Reducer Flange]
  Flange --> Cover[Cover with "FH" Embossing]
  Cover --> Cap[Cap (Cast Iron)]

This guarantees robustness, visibility, and conformity to IS 909 standards.

Key Construction and Dimension Highlights from IS 909

1. Outlet Threading:

   • Outlet features external rounded threads with 2 threads per 25.4 mm (1 inch).
   • Thread taper ratio is 1 in 20 on each side.
   • Thread dimensions comply with IS 4694, such as 32 × 6 mm pitch.
   • Thread thickness tolerance is +0 / -0.4 mm.

2. Material Specifications:

3. Tolerance Limits (per IS 2102:1962):

   • ±2 mm for dimensions up to 15 mm.
   • ±2 mm for 16 to 50 mm.
   • ±5 mm for dimensions greater than 51 mm.

4. Surface Box:

   • Must weigh at least 135 kg.
   • For a second sluice valve, it should align with IS 3950:1979.

5. Cap and Chain Details:

   • Cap fully encloses outlet threads.
   • Chain minimum diameter: 3 mm steel stock or equivalent.
   • Chain must be treated to resist corrosion.

Thread Dimension Summary

flowchart LR
  HydrantOutlet[Hydrant Outlet] --> ExtThread[External Rounded Thread]
  ExtThread --> FlangedPipe[Flanged Pipe Connection]
  FlangedPipe --> OutletCap[Outlet Cap]

IS 909 Coating Guidelines for Parts Excluding Sluice-Valve (Clause 8)

• Cleaning: All cast iron components must be thoroughly cleaned immediately post-casting and prior to machining.
• Coating Process: Components are dipped in a bituminous-based bath as per IS 158:1981.
• Bath Temperature: Maintained between 143°C and 166°C.
• Coating Purpose: To protect parts from rusting before machining or further finishing.

Material and Component Details

Thread and Attachment Details (Clause 2.54 & Figure 3)

• External rounded threads with 2 threads per 2.54 cm (~10 TPI).
• Steel chain, minimum diameter 3 mm, treated to resist corrosion, connects cap and outlet.
• Parts must be free from burrs and defects; no welding or repairs permitted.

Coating Process Flow

flowchart LR
  Casting --> Cleaning --> BituminousDip --> CoatingFormation --> Machining & Finishing

Refer to IS 158:1981 and Clause 8.3 of IS 909 for detailed coating composition and performance.

Summary of Performance Requirements in IS 909

The standard emphasizes valve functionality, particularly the Valve Seat Tightness Test.

Key Performance Test:

• Valve Seat Tightness Test: Ensures no leakage occurs past the valve seat when subjected to designated pressure.

Testing Guidelines:

• Round test results according to IS 2:1960, maintaining the specified number of significant figures.
• Compliance depends on final test or calculation outcomes.

Typical Test Parameters:

Flowchart

flowchart TD
  Valve --> ValveSeat
  ValveSeat --> TightnessTest{Leakage?}
  TightnessTest -- Pass --> SeatTight[Valve Seat Tight]
  TightnessTest -- Fail --> LeakageDetected[Leakage Found]

In brief: IS 909 requires valves to pass tightness tests under pressure, with results rounded per IS 2:1960. Annex A provides related standards.

Acceptance Guidelines per IS 909

• Rounding: Final test and analysis values must be rounded following IS 2:1960 rules, preserving the original number of significant digits.

• Stop Valve Testing (Clause 1.4):

  • Valve spindle must be fully screwed down to close the valve.
  • Apply hydrostatic pressure of 1.4 MN/m² (14 bar) to the valve inlet.
  • No leakage through valve or seat is permissible.

• Hydrant Testing (Clause 11):

  • Each hydrant undergoes standardized testing.
  • Acceptance depends on meeting all defined performance criteria.

• Refer to Annex A for related Indian Standards.

Hydrostatic Test Summary

flowchart TD
  CloseValve --> ApplyPressure
  ApplyPressure --> LeakageCheck{Leakage?}
  LeakageCheck -- No --> AcceptValve
  LeakageCheck -- Yes --> RejectValve

This ensures valves and hydrants comply with safety and functional standards.

Marking Specifications for Fire Hydrants (Clauses 12.1 & 12.2.1)

• Mandatory Markings:

  • Manufacturer’s name or trademark.
  • Year of manufacture.

• Optional Marking:

  • The Standard Mark may be applied as per Clause 12.2.1.

Related Material Standards (Annex A)

Thread Specifications (Clause 2.54)

• Outlet threads: External rounded threads, 2 threads per 2.54 cm (~8 TPI).
• Thread standards conform to IS 4694.
• Outlet caps cover threads and are secured by chains to prevent loss.

Dimensional Tolerances (IS 2102:1962)

Marking and Components Diagram

graph TD
  Hydrant --> Marking[Marking Details]
  Marking --> Manufacturer[Manufacturer Name/Trademark]
  Marking --> Year[Year of Manufacture]
  Marking --> StdMark[Standard Mark (Optional)]
  Hydrant --> Components
  Components --> Body[Body (IS 210)]
  Components --> Outlet[Outlet (IS 318)]
  Components --> Spindle[Spindle (IS 319)]
  Components --> Washer[Washer (IS 937)]
  Components --> Chain[Chain (Galvanized MS)]

List of Indian Standards Referenced in IS 909

IS 909 cites various Indian Standards critical for ensuring the quality of materials and components used in fire-fighting hydrants, detailed in Annex A:

Notes:

• These standards govern material properties, fasteners, gaskets, coatings, and accessories.
• Use of the Standard Mark is encouraged as per Clause 12.2.1.
• Rounding off follows IS 2:1960.

Diagram Depicting Referenced Standards

graph LR
  IS909[IS 909 Fire Hydrant Specification] --> IS210[IS 210 - Cast Iron]
  IS909 --> IS318[IS 318 - Gun Metal]
  IS909 --> IS319[IS 319 - Brass]
  IS909 --> IS937[IS 937 - Rubber Washers]
  IS909 --> IS1367[IS 1367 - Fasteners]
  IS909 --> IS158[IS 158 - Bituminous Paint]
  IS909 --> IS3950[IS 3950 - Surface Boxes]