--- title: "API 602 Gate Valve: A Complete Guide to Forged Steel Gate Valve Standards" date: 2026-09-25T06:35:15Z modified: 2026-09-30T00:52:17Z permalink: "https://www.xintaivalves.com/blog/gate-valve/api-602-gate-valve-complete-guide/" type: post status: publish excerpt: "" wpid: 16914 categories: - Gate Valve featured_image: "https://www.xintaivalves.com/wp-content/uploads/2026/09/94387c876d97bafb6d8a96d7a99c61b1.webp" featured_image_alt: API 602 forged steel gate valve for high-pressure service timestamp: 2026-09-30T00:52:17Z tags: - Gate Valve --- Table of Contents [Toggle](#) - [Quick Answer](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#Quick_Answer) - [What Is the API 602 Standard?](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#What_Is_the_API_602_Standard) - [What Is the Scope and Applicability of API 602?](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#What_Is_the_Scope_and_Applicability_of_API_602) - [Sizes and Pressure Classes Covered](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#Sizes_and_Pressure_Classes_Covered) - [Valve Types and Industries Served](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#Valve_Types_and_Industries_Served) - [What Are the Design Requirements Under API 602?](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#What_Are_the_Design_Requirements_Under_API_602) - [Body-Bonnet Connection Types](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#Body-Bonnet_Connection_Types) - [Stem, Backseat, and Gate Design](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#Stem_Backseat_and_Gate_Design) - [What Materials Does API 602 Specify?](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#What_Materials_Does_API_602_Specify) - [Standard Body and Trim Materials](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#Standard_Body_and_Trim_Materials) - [Material Testing Requirements](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#Material_Testing_Requirements) - [What Testing and Inspection Does API 602 Require?](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#What_Testing_and_Inspection_Does_API_602_Require) - [Shell and Seat Testing](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#Shell_and_Seat_Testing) - [NDE and Fire-Safe Testing](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#NDE_and_Fire-Safe_Testing) - [How Does API 602 Differ From API 600?](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#How_Does_API_602_Differ_From_API_600) - [Manufacturing Process and Size Range](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#Manufacturing_Process_and_Size_Range) - [Quick Comparison Table](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#Quick_Comparison_Table) - [Where Should You Use a Compact Forged Steel Valve?](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#Where_Should_You_Use_a_Compact_Forged_Steel_Valve) - [High-Pressure and High-Temperature Scenarios](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#High-Pressure_and_High-Temperature_Scenarios) - [Selection Checklist](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#Selection_Checklist) - [Conclusion](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#Conclusion) - [Frequently Asked Questions](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#Frequently_Asked_Questions) - [What size range does API 602 cover?](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#What_size_range_does_API_602_cover) - [Is API 602 the same as API 600?](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#Is_API_602_the_same_as_API_600) - [What pressure classes does API 602 cover?](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/api-602-gate-valve-complete-guide.md#What_pressure_classes_does_API_602_cover) ## Quick Answer API 602 covers compact forged steel gate, globe, and check valves, NPS ¼ through NPS 4 (DN 8 to DN 100), Class 150 through Class 1500. This standard establishes minimum design, material, and test requirements for achieving reliable performance of small-bore valves subjected to high pressure and cyclic loading. Xintai Valves manufactures a series of [API 602 gate valves](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/page/api-602-forged-steel-valve.md) to this standard, fabricated in carbon steel, alloy steel, and stainless steel grades. ## What Is the API 602 Standard? API 602 is the American Petroleum Institute standard that covers compact forged steel valves, including gate, globe, and check types of NPS 4 and below. While an api 602 gate valve may experience the same levels of pressure and cyclic loading as a larger valve,forging produces a denser, more uniform grain structure than casting, which is why small-bore high-pressure valves are commonly forged,See our guide on [what sets forged steel gate valves apart](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/understanding-forged-steel-gate-valves.md) for more detail. ## What Is the Scope and Applicability of API 602? ![Forged steel valve grain structure for high-pressure service](https://www.xintaivalves.com/wp-content/uploads/2026/09/image-38-1024x512.png) API 602 is applicable for valves from NPS ½ through NPS 4 (DN 15 to DN 100) and includes pressure Class 150, 300, 600, 800, and 1500. Class 800 is a common intermediate rating for socket-weld ends. ### Sizes and Pressure Classes Covered Class 800 is between Class 600 and Class 900 and is not a standard ASME B16.34 rating on its own. It is used specifically for small forged valves with threaded or socket-weld connections. ### Valve Types and Industries Served The standard covers gate, globe, and check valves. Refineries, petrochemical plants, and power stations use these valves for instrument lines, chemical injection, and small-bore isolation. API 602 is one of several API valve standards, alongside [API 600](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/what-is-api-600-gate-valve.md), 6D, and 608; see our guide to comparing API valve standards. ## What Are the Design Requirements Under API 602? API 602 establishes minimum design requirements for the body-bonnet joint, stem, and internals to maintain small valve leak-tightness under repeated cycling. ### Body-Bonnet Connection Types Bolted bonnet and welded bonnet designs cover the majority of Class 800 and 1500 valves. Bolted and welded bonnets are the most common designs for Class 800 and 1500 valves; some manufacturers also offer pressure-seal variants. Welded bonnets remove the body-bonnet leak path, which suits services where external leakage must be minimized, whereas bolted bonnets can be more accessible for field maintenance and inspection. ![API 602 gate valve bolted welded and pressure-seal bonnet](https://www.xintaivalves.com/wp-content/uploads/2026/09/image-39-1024x512.png) ### Stem, Backseat, and Gate Design A rising stem with an Acme thread offers visual confirmation of valve position. A backseat can isolate the packing chamber from process pressure when the valve is fully open, depending on the valve design and operating procedure. Solid wedge gates are standard for tight shutoff, but some manufacturers can offer an api 602 bellows gate valve option. This provides a metal bellows around the stem for near-zero fugitive emissions. ## What Materials Does API 602 Specify? API 602 lists forged material grades for the body, bonnet, and trim based on fluids, temperatures, and corrosion resistance. ### Standard Body and Trim Materials Carbon steel forgings (ASTM A105) are suitable for general service. Chrome-moly grades (F11, F22) can handle elevated temperature, while stainless grades (F304, F316) can offer corrosion resistance in chemical and offshore service. Trim options include hardfaced seats, such as cobalt-based alloy facings, for erosive or high-cycle duty. Soft-seated trim is suitable for tight shutoff at lower pressure and temperature. ### Material Testing Requirements Each heat of forging material must have a mill test report confirming chemical composition and mechanical properties. Buyers can also request additional testing, such as impact testing for low-temperature service. ## What Testing and Inspection Does API 602 Require? Every finished valve undergoes shell and seat testing prior to shipment. These tests confirm body pressure retention and seat shutoff within an allowable leakage rate. ### Shell and Seat Testing Shell tests verify the pressure integrity of the body and bonnet, usually in accordance with API 598. Seat tests verify shutoff capability against the allowable leakage rate defined in API 598. ### NDE and Fire-Safe Testing Buyers can request magnetic particle or dye penetrant inspection on forgings and welds. Fire-safe design, if required, is verified according to API 6FA, the fire test standard for gate, globe, and check valves. ## How Does API 602 Differ From API 600? API 602 and API 600 both cover [steel gate valves](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/page/gate-valve-manufacturer.md), but they differ in size range and manufacturing process. Understanding the difference can help buyers choose the correct gate valve for their application. ### Manufacturing Process and Size Range API 600 covers cast steel gate valves from NPS 1 up to larger sizes, with heavier wall sections and a bolted bonnet construction. API 602 covers forged valves at NPS 4 and below, with denser grain structure at small bore sizes. ### Quick Comparison Table | Feature | API 602 | API 600 | | --- | --- | --- | | Construction | Forged steel | Cast steel | | Size range | NPS ½ to NPS 4 | NPS 2 and larger | | Valve types | Gate, globe, check | Gate only | | Pressure classes | 150 to 1500 | 150 to 2500 | | Typical bonnet | Bolted, welded, pressure-seal | Bolted, pressure-seal | An api 602 vs api 600 gate valve comparison would most likely depend on the pipe size. Once a line exceeds NPS 4, API 600 becomes the standard. See the [comparison of API 602 and API 600](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/post/what-is-api-600-api-602-and-their-difference.md) for a more detailed discussion of differences. ## Where Should You Use a Compact Forged Steel Valve? API 602 valves are suitable for small-bore lines that carry high pressure, high temperature, or hazardous fluids. Instrument connections, chemical injection points, and sample lines are some candidates. ### High-Pressure and High-Temperature Scenarios Steam lines, gas gathering systems, and high-pressure chemical injection skids often use Class 800 or 1500 forged valves. The forged body is better able to withstand the fatigue of repeated thermal cycling. ### Selection Checklist Confirm size, pressure class, and end connection type first. Then check body material, trim, bonnet type, and whether fire-safe or bellows-seal features are relevant to your service. API 602 Forged Steel Gate Valve [ ![API 602 forged steel gate valve for high-pressure service](https://xintaivalves.com/wp-content/uploads/2022/02/149-master-graph.jpg) 🛠 API 602 Forged Steel Gate Valve XINTAI API 602 forged steel gate valves are designed for small-bore, high-pressure applications in oil and gas, chemical, steam, and petrochemical systems. Available in 1/2"–2" sizes with Class 150–2500 pressure ratings and multiple end connections. View Product ](https://www.xintaivalves.com/products/forged-steel-gate-valve/)## Conclusion Xintai Valves manufactures [API 602 forged steel gate valves](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/taxonomy/product/forged-wedge-gate-valve.md) in sizes from 1/2 inch to 2 inches, with pressure ratings from Class 150 through Class 1500. Available body materials include A105, F304, F304L, F316, F316L, F11, F22, and F51. The company is ISO 9001 certified and holds CE and API certifications for applicable products. They supply buyers within the oil and gas, petrochemical, and power generation industries, with bases in Wenzhou, Tianjin, and Lishui. Browse Xintai’s [forged steel gate valve range](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/page/gate-valve-collection.md) to compare sizes, pressure classes, and materials. ## Frequently Asked Questions ### What size range does API 602 cover? API 602 applies to gate, globe, and check valves from NPS ½ through NPS 4 (DN 15 to DN 100). Larger forged valves fall outside the standard’s scope entirely. ### Is API 602 the same as API 600? No. API 600 covers cast steel gate valves NPS 2 and larger. API 602 covers forged steel gate, globe, and check valves at NPS 4 and below. ### What pressure classes does API 602 cover? The standard covers Classes 150, 300, 600, 800, and 1500. Class 800 is an intermediate class commonly used for compact threaded and socket-weld valves. Class 800 is a common intermediate rating used for small forged valves with threaded or socket-weld ends. [Get a Quote](https://www.xintaivalves.com/wp-content/uploads/wp-mfa-exports/page/contact.md)