ANSI Gate Valve

Gate valves are designed primarily for positive on/off isolation, not continuous throttling. In Nigeria’s oil & gas, refining and gas-transmission infrastructure, they are selected according to pressure class, nominal size, body and trim materials, bonnet construction and end connection. ANSI Gate Valve Suppliers in Nigeria can provide wedge-type steel gate valves for process pipelines and equipment requiring dependable isolation. 

Key Features

• Wedge / Parallel Gate: Provides positive isolation when fully closed.

• Full-Bore Flow: The gate moves clear of the passage when fully open.

• Bi-Directional Isolation: Suitable for controlling flow from either direction.

• Rising / Non-Rising Stem: Selected according to installation and operating requirements.

• Manual or Actuated: Handwheel, gearbox or actuator operation can be specified.

• Multiple Pressure Classes: Available according to the required ASME pressure class.

Technical Specifications

API/ISO 10434 covers bolted-bonnet steel gate valves in Classes 150–2500 and NPS 1–24, including wedge or parallel seating and flanged or butt-welding ends.

Materials & Components

Carbon Steel

• Body / Bonnet: ASTM A216 WCB

• Gate: ASTM A216 WCB

• Stem: ASTM A182 F6a / Type 410

• Seat: A105 + 13Cr / Stellite hardfacing

• Backseat: 13Cr / 410 Stainless Steel

• Packing: Flexible Graphite

• Gasket: 304/316 Stainless Steel + Graphite Spiral-Wound

Stainless Steel

• Body / Bonnet: ASTM A351 CF8 / CF8M

• Gate: ASTM A351 CF8M

• Stem: ASTM A182 F316

• Seat: 316 Stainless Steel / Stellite hardfacing

• Backseat: 316 Stainless Steel

• Packing: Flexible Graphite / PTFE

• Gasket: 316 Stainless Steel + Graphite Spiral-Wound

Alloy Steel

• Body / Bonnet: ASTM A217 WC6 / WC9

• Gate: ASTM A217 WC6 / WC9

• Stem: ASTM A182 F11 / F22

• Seat: 13Cr / Stellite hardfacing

• Packing: Flexible Graphite

• Gasket: Stainless Steel + Graphite Spiral-Wound

Applications in Nigeria

• Gas Transmission: Isolation on large gas pipelines and associated station piping, including the OB3 Pipeline and AKK gas corridor, where sectional isolation is required.

• Refining: Process and utility isolation at facilities such as the Dangote Oil Refinery in Lagos, where gate valves are used for on/off service across high-pressure and high-temperature systems.

• Petrochemical Processing: Suitable for hydrocarbon and utility lines where metal-seated gate valves provide isolation rather than throttling.

• Power & Industrial Utilities: Applicable to steam, cooling-water and process-utility isolation where the selected material and pressure class match the service.

Standards

Relevant requirements include API 600 / ISO 10434 for steel gate-valve design, ASME B16.34 for pressure-temperature ratings, ASME B16.5/B16.47 for flanges, ASME B16.25 for butt-weld ends, ASME B16.10 for face-to-face dimensions and API 598 for inspection and pressure testing.