Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
1. Scope and Applicability of API Publ 4761-2011
1. Scope and Applicability of API Publ 4761-2011
- Valves with flanged ends conforming to ASME B16.5 or ASME B16.47.
- Valves with butt-welding ends conforming to ASME B16.25.
- Standard and full port configurations.
- Rising stem and non-rising stem designs (with specific limitations).
Tip: When specifying valves for critical or high-temperature services, API Publ 4761-2011 provides a robust framework. However, for compact gate valves (NPS 4 and smaller), designers should cross-reference with API 602, which imposes additional pressure-loss and seat-leakage criteria.
2. Technical Requirements and Material Specifications
2.1 Pressure-Temperature Ratings
2.2 Materials of Construction
2.3 Gate and Seat Design
| Component | Standard Materials | Trim Level 1 (Standard) | Trim Level 5 (Corrosion Resistant) |
|---|---|---|---|
| Body / Bonnet | ASTM A216 WCB | ASTM A216 WCB | ASTM A352 LCC |
| Wedge / Gate | ASTM A216 WCB | ASTM A216 WCB + Hardface | 13% Cr (AISI 410) |
| Seat Ring | ASTM A216 WCB | 13% Cr (AISI 410) | Inconel 718 |
| Stem | ASTM A182 F6a | ASTM A182 F6a (13% Cr) | Inconel 625 |
| Bonnet Bolting | ASTM A193 Gr. B7 | ASTM A193 Gr. B7 / Gr. B7M | ASTM A193 Gr. B7M |
Warning: Avoid substituting bolting materials without re-verifying the pressure-temperature rating. The use of low-strength materials like ASTM A193 Grade B8 Class 2 requires a de-rating of the standard pressure-temperature limits.
3. Design, Testing, and Quality Assurance
3.1 Shell and Seat Leakage Tests
3.2 Backseat and Stem Seals
Best Practice: Implementing a torque control procedure for bonnet bolting during assembly is a proven method to ensure compliance with the gasket seating stress requirements outlined in Appendix D of the standard. This drastically reduces field fugitive emissions.
3.3 Documentation and API Monogram
4. Compliance Notes and Implementation Insights
4.1 NACE MR0175 / ISO 15156 Compliance
4.2 Inspection Frequency
- Dimensional inspection of the wedge and seat ring contact area.
- Material traceability verification for shell castings.
- Post-hydrotest cleaning and drying for oxygen service valves.
Critical Compliance Risk: Failure to strictly follow the post-hydrotest drying procedures can lead to catastrophic stress corrosion cracking in sour service valves. Ensure that halide content in test water is monitored and documented.
4.3 End Preparation
Frequently Asked Questions (FAQ)
Q: What is the formal relationship between API Publ 4761-2011 and API 600?
A: API Publ 4761-2011 is the exact title of the specification widely known as API 600. The publication number 4761 serves as the identifying standard number for the 2011 edition of the “Steel Gate Valves with Flanged or Butt-Welding Ends, and Bolted Bonnets” specification. It supersedes the previous editions and provides the authoritative technical baseline for this valve type.
A: API Publ 4761-2011 is the exact title of the specification widely known as API 600. The publication number 4761 serves as the identifying standard number for the 2011 edition of the “Steel Gate Valves with Flanged or Butt-Welding Ends, and Bolted Bonnets” specification. It supersedes the previous editions and provides the authoritative technical baseline for this valve type.
Q: Are flanged end valves covered by this standard?
A: Yes. The standard provides comprehensive design and dimensional requirements for both flanged end valves (per ASME B16.5 and B16.47) and butt-welding end valves (per ASME B16.25).
A: Yes. The standard provides comprehensive design and dimensional requirements for both flanged end valves (per ASME B16.5 and B16.47) and butt-welding end valves (per ASME B16.25).
Q: Does this standard apply to cryogenic gate valves?
A: While API Publ 4761-2011 includes material specifications for low-temperature carbon steel (e.g., LCB, LCC), valves specifically designed for cryogenic service often require an extended bonnet and special seat leak tests that go beyond the scope of this specification. For cryogenic applications, designers typically reference MSS SP-134 or ISO 28921 in addition to the baseline API Publ 4761 requirements.
A: While API Publ 4761-2011 includes material specifications for low-temperature carbon steel (e.g., LCB, LCC), valves specifically designed for cryogenic service often require an extended bonnet and special seat leak tests that go beyond the scope of this specification. For cryogenic applications, designers typically reference MSS SP-134 or ISO 28921 in addition to the baseline API Publ 4761 requirements.
Q: What are the main testing requirements under API Publ 4761?
A: The standard mandates a hydrostatic shell test at 1.5× the 100°F pressure rating and a hydrostatic seat test. When required by the purchase order, a low-pressure pneumatic seat test is performed. The inspection, testing, and acceptance criteria follow API 598.
— This article is prepared for general technical information referencing the 2011 edition of the standard. Always consult the latest official API publication for compliance and up-to-date requirements. 2026. “content”: “A: The standard mandates a hydrostatic shell test at 1.5× the 100°F pressure rating and a hydrostatic seat test. When required by the purchase order, a low-pressure pneumatic seat test is performed. The inspection, testing, and acceptance criteria follow API 598.
1. Scope and Applicability of API Publ 4761-2011
API Publication 4761-2011 establishes the comprehensive requirements for steel gate valves featuring flanged or butt-welding end connections and bolted bonnets. This publication serves as the primary specification for valves used across upstream, midstream, and downstream oil and gas applications, as well as in power generation and industrial process plants. It covers valve sizes from NPS 2 to NPS 48, with pressure Class designations ranging from Class 150 to Class 2500, in accordance with ASME B16.34.
The standard specifically addresses the design, material selection, manufacturing, and testing of bolted bonnet gate valves. It applies to both straight-through and conduit-type gate valves. The scope explicitly includes:
- Valves with flanged ends conforming to ASME B16.5 or ASME B16.47.
- Valves with butt-welding ends conforming to ASME B16.25.
- Standard and full port configurations.
- Rising stem and non-rising stem designs (with specific limitations).
Tip: When specifying valves for critical or high-temperature services, API Publ 4761-2011 provides a robust framework. However, for compact gate valves (NPS 4 and smaller), designers should cross-reference with API 602, which imposes additional pressure-loss and seat-leakage criteria.
2. Technical Requirements and Material Specifications
2.1 Pressure-Temperature Ratings
The standard mandates that valve shell design must comply with the pressure-temperature ratings defined in ASME B16.34. The minimum wall thickness requirements are specified in table format within the publication and must be strictly verified during the design verification phase.
2.2 Materials of Construction
Material selection is strictly governed by the standard. The body, bonnet, and wedge materials must conform to applicable ASTM material standards. Common materials include ASTM A216 Grade WCB, WCC, and LCB for low-temperature service. API Publ 4761-2011 also provides guidance on internal trim materials for various service conditions, such as Type 13Cr for corrosion resistance and Inconel overlays for severe applications.
2.3 Gate and Seat Design
The standard requires solid wedge or flexible wedge designs. Seat rings must be renewable, and the wedge faces must be precision machined to ensure a bubble-tight shut-off in the closed position. The gate-to-seat clearance is a critical dimensional feature that must be controlled to ensure proper sealing.
| Component | Standard Materials | Trim Level 1 (Standard) | Trim Level 5 (Corrosion Resistant) |
|---|---|---|---|
| Body / Bonnet | ASTM A216 WCB | ASTM A216 WCB | ASTM A352 LCC |
| Wedge / Gate | ASTM A216 WCB | ASTM A216 WCB + Hardface | 13% Cr (AISI 410) |
| Seat Ring | ASTM A216 WCB | 13% Cr (AISI 410) | Inconel 718 |
| Stem | ASTM A182 F6a | ASTM A182 F6a (13% Cr) | Inconel 625 |
| Bonnet Bolting | ASTM A193 Gr. B7 | ASTM A193 Gr. B7 / Gr. B7M© 2026 tnlab.org — This article is for educational and technical reference purposes.
📥 Standard Documents DownloadTrending now |