cast iron screw-down stop valves and stop and check valves for water works purposes

IS 9338: Scope - Key Specifications & Tables

Scope:
IS 9338 covers dimensions, materials, and design requirements for stop valves and stop & check valves.

Key Tables & Specifications:

1. Body Seat Rings Dimensions (L-shaped cross-section)

(Clause 6.6.2, Table 3)

2. Valve Dimensions (Face to Face, Handwheel, etc.)

(Clause 6.13, Table 5)

Tolerance on A & A1:

• ≤ 200 mm: ±1 mm
• 201–400 mm: ±2 mm
• 401–600 mm: ±3 mm
• 601–800 mm: ±4 mm
• 801–1000 mm: ±5 mm

3. Materials for Components

(Clause 5.1, Table 1)

| Component | Material | IS Code

IS 9338: Definitions & Key Specifications Summary

Clause 2.1: Definitions

• Definitions for valves and parts follow IS: 4854 (Part 1)-1969 (Glossary for screw-down stop, check, and gate valves).

Key Table: Body Seat Ring Dimensions (L-shaped cross-section) — Clause 6.6.2

All dimensions in mm.

Materials for Stop Valve Components — Clause 5.1 (Table 1)

Nominal Pressure (PN) - IS 9338 Key Points

• Definition (Clause 3.1):
  Nominal Pressure (PN) is the maximum permissible gauge working pressure in MPa for valves of specified sizes.

• Nominal Pressure Table (Clause 3.1):

• Hydrostatic Test Pressure & Duration (Clause 8.1, Table 6):

*Back seat test is performed where specified.

• Nominal Size (Clause 4.1.1):
  Nominal size corresponds to the nominal bore of the waterway; actual bore shall not be less than the nominal size.

Summary:

• PN defines the pressure rating for valves.
• Testing ensures valve integrity at pressures above PN.
• Sizes and pressures are standardized for compatibility and safety.

flowchart TD
    A[Valve Size] --> B{Nominal Pressure (PN)}
    B -->|Up to 150 mm| C[PN = 1.6 MPa]
    B -->|200 to 300 mm| D[PN = 1.0 MPa]
    C --> E[Hydrostatic Test: 2.4 MPa, 5 min (Body)]
    D --> F[Hydrostatic Test: 1.5 MPa, 5 min (Body)]

This clarifies nominal pressure designation and testing requirements per IS

IS 9338 - Nominal Sizes Key Points

1. Nominal Size Definition (Clause 4.1.1):

   • Nominal size = nominal bore of waterway.
   • Actual bore ≥ nominal size.

2. Nominal Pressure (PN) & Size Range (Clause 3.1):

3. Body Seat Ring Dimensions (L-shaped cross-section) (Clause 6.6.2, Table 3):

4. Flange Dimensions for Stop Valves (Clause 6.3, Table 2):

IS 9338 - Materials for Stop Valves and Stop & Check Valves (Clause 5.1)

Key Materials & Specifications (Table 1 Highlights):

Additional Specifications:

• Coating for Cast Iron Parts (Clause 7.1):
  Dip cast iron parts in tar-based bath at 143–166°C immediately after casting to prevent rust.

• Stem & Stuffing Box Dimensions (Table 4):
  Stem diameter ranges from 14 mm (15 mm valve) to 36 mm (300 mm valve).
  Square on top of stem varies from 9 ± 0.5 mm to 24 ± 0.5 mm.

• Body Seat Ring Dimensions (Table 3):
  For valve size 15 mm to 300 mm, dimensions A, B, C, D vary (e.g., for 15 mm valve: A=8 mm, B=5 mm, C=2 mm, D=3 mm).

Summary Diagram of Material-

IS 9338: Design & Construction Key Points

1. Materials for Stop Valves (Table 1, Clause 5.1)

2. Body Seat Ring Dimensions (Table 3, Clause 2.0)

3. Testing (Clause 2.1.3)

• Test pressure applied:
  • Globe valve: Under the disc
  • Globe stop/check valve: Under

IS 9338 - Coating Specifications and Key Details

Coating Requirements (Clause 7.1)

• Process: Immediately after casting and before machining, clean all cast iron parts thoroughly.
• Coating: Dip in a tar-based bath maintained at 143–166°C.
• Purpose: Prevent rusting; coating must meet properties in Clause 7.3.
• Alternative: Two coats of Black Japan (IS: 341-1971 Type 8) or paint per IS: 9862-1981 can be applied (Clause 7.4).

Testing of Coating (Note 2, Clause 6.13)

• Test one smallest and one largest size piece from each bath.
• For tar-based paints, test representative piece 150 x 100 x 10 mm from each bath.

Dimensional Tolerances on Coated Valves (Table 5, Clause 6.13)

Summary Diagram of Coating Process

flowchart TD
    A[Cast Iron Parts] --> B[Thorough Cleaning]
    B --> C[Dip in Tar-Based Bath (143-166°C)]
    C --> D[Coating Formation]
    D --> E[Machining & Assembly]
    E --> F[Testing: Smallest & Largest Samples]

This ensures corrosion protection and dimensional accuracy per IS 9338.

IS 9338 - Testing of Valves: Key Specifications & Formulas

Clause 8.1: Hydrostatic Testing

• Each valve must undergo hydrostatic tests per Appendix B.
• Valve must show no leakage during the test.

Table 6: Test Pressure & Duration for Valves

(*) Back seat test is performed where specified.

Seat Test Pressure Application (Clause B-2.1.3)

• Globe valve: Pressure under the disc, open end to atmosphere.
• Globe stop & check valve:
  1. Under the disc,
  2. Outlet end with stem raised (pressure on top of disc).
• Check valves: Pressure applied at outlet end.

Summary Diagram: Testing Procedure Flow

flowchart TD
    A[Valve Ready for Testing] --> B[Hydrostatic Test per Appendix B]
    B --> C{Test Type}
    C -->|Body Test| D[Apply Pressure as per Table 6]
    C -->|Seat Test| E[Apply Pressure under Disc or Outlet]
    C -->|Back Seat Test| F[Apply Pressure at Back Seat]
    D --> G[Hold for Duration (5 min)]
    E --> H[Hold for Duration (2 min)]
    F --> I[Hold for Duration (5 min)]
    G & H & I --> J[Check for Leakage]
    J -->|No Leakage| K[Pass]
    J -->|Leakage| L[Fail - Rework]

Note: Testing ensures valve integrity and leak tightness before commissioning. Always refer to Appendix B for

IS 9338: Information to be Supplied with Enquiry or Order (Clause 9.1 & Appendix A)

When placing an enquiry or order for valves, the purchaser must provide detailed specifications as per Appendix A:

• Nominal size of valve
• Type of valve: Stop or stop & check; Straight, angle, or oblique
• Trim material: Stainless steel or bronze
• Disc type: Flat, mitre, ball/cone, or plug
• Flange drilling: Drilled or undrilled
• Back seat: Required or not
• Open/Shut indicator: Required or not
• Chainwheel operation: Required or not; specify type and whether chain is supplied
• Gearing: Type and arrangement (if gear operation is needed)
• Power operation: Type (if any)
• Test certificates: Inspection, witnessing, or certificate of conformity

Key Testing Table (Table 6, Clause 8.1)

*Back seat test only if specified.

Summary Diagram of Information Flow

flowchart TD
    A[Purchaser] --> B[Enquiry/Order]
    B --> C{Provide Information}
    C -->|Nominal Size| D[Valve Specification]
    C -->|Valve Type| D
    C -->|Trim Material| D
    C -->|Disc Type| D
    C -->|Flange Drilling| D
    C -->|Back Seat| D
    C -->|Indicator| D
    C -->|Chainwheel| D
    C -->|Gearing| D

IS 9338: Marking - Key Points & Specifications

Clause 10.1.2 governs the use of the Standard Mark as per the Bureau of Indian Standards Act, 1986.

• Licence for Standard Mark use: Manufacturers must obtain permission from BIS under specified conditions.
• Details for licensing are available directly from the BIS.

Related Dimensions & Specifications (for valves, relevant to marking identification)

Tolerances on Valve Dimensions (Face to face A & Centre to face A1)

Notes on Coating (related to marking & identification)

• Cast iron parts must be coated immediately after casting (tar-based bath at 143-166°C).
• Test pieces from each bath must be tested for coating quality (150x100x10 mm).
• Sluice valves may be assembled without coating if inspection is required.

Summary

• Marking: Use of Standard Mark strictly per BIS licensing.
• Valve dimensions and tolerances are standardized for identification and quality control.
• Coating ensures durability and proper marking visibility.

For detailed

IS 9338 - Packing and Storage Key Points

Packing (Clause 11.1a)

• Valves supplied with discs closed to protect internals.
• Bright parts rust-protected (e.g., oil coating).
• Smooth flanged joint faces protected against damage.
• Fragile parts wrapped with wood wool or similar cushioning.

Storage (Clause 11.1b)

• Store valves in roofed, clean stores away from dirt and moisture.

Stuffing Box Depth (Clause 6.12)

• Depth must accommodate at least 5 turns of packing.
• Refer to Table 4 (IS 9338) for exact stuffing box depths based on valve size.

Summary Table: Packing & Storage Requirements

Additional Notes

• Proper packing ensures no damage during transit.
• Storage prevents corrosion and contamination.
• Refer to IS 9338 Table 4 for stuffing box depth specifics by valve size.

flowchart TD
    A[Packing] --> B[Disc Closed]
    A --> C[Rust Protection]
    A --> D[Fragile Parts Wrapped]
    E[Storage] --> F[Roofed Store]
    E --> G[Clean & Dry]
    H[Stuffing Box] --> I[Depth ≥ 5 turns packing]

For detailed dimensions and stuffing box depths, consult Table 4 of IS 9338.

IS 9338 - Operation Key Points

Clause 12.4: Chainwheel Operation

• Specify type of chainwheel and chain supply in the order.

Clause 12.5: Gear Operation

• Specify type and arrangement of gearing in enquiry/order.

Clause 12.6: Actuator Operation

• Provide actuator details, power supply, and max pressure differential across valve.

Body Seat Ring Dimensions (Clause 6.6.2 & Fig. 3)

Additional Notes

• For gear and actuator operations, always specify design max pressure differential to ensure correct selection.
• Chainwheel and gear arrangements affect torque requirements; consult relevant mechanical design standards for sizing.
• Bolt circle and hole diameters for flange drilling are per Fig. 2

IS 9338 - Key Information to be Supplied with Enquiry or Order (Clause 9.1 & Appendix A)

The purchaser must provide the following details:

• Nominal size of valve
• Type of valve:
  • Stop or stop and check
  • Straight, angle, or oblique
• Trim material: Stainless steel or bronze
• Disc type: Flat, mitre, ball/cone, or plug
• Flange drilling: Drilled or undrilled
• Back seat: Required or not
• Open/shut indicator: Required or not
• Chainwheel operation: Required or not; specify type and if chain is needed
• Gearing: Type and arrangement if gear operation is needed
• Power operation: Type if required
• Test certificates: Inspection, witnessing, or conformity certificates

Testing Details (Clause 8.1 & Table 6)

*Back seat test only if specified.

Summary Diagram

flowchart TD
    A[Enquiry/Order] --> B{Information to supply}
    B --> C[Nominal size]
    B --> D[Valve type]
    B --> E[Trim material]
    B --> F[Disc type]
    B --> G[Flange drilling]
    B --> H[Back seat]
    B --> I[Open/Shut indicator]
    B --> J[Chainwheel operation]
    B --> K[Gearing type & arrangement]
    B --> L[Power operation]
    B --> M[Test certificates]

This ensures clarity and compliance with IS 9338 requirements for valve ordering and testing.

IS 9338: Testing of Valves - Key Formulas, Tables & Specs

1. Hydrostatic Test Requirements (Clause 8.1 & Table 6)

* Back seat test only if specified.

2. Test Procedure (Appendix B)

• Valve subjected to hydrostatic pressure as per above.
• Duration as per Table 6.
• No leakage allowed during/after test.

3. Information to Supply with Order (Appendix A)

• Nominal size, valve type, trim material.
• Disc type, flange drilling, back seat requirement.
• Indicator, chainwheel, gearing, power operation.
• Test certificates or inspection requirements.

4. Material Specifications (Table 1, Clause 5.1)