High-Performance High Pressure Steam Gate Valves
Designed for zero-leakage isolation in critical high-temperature, high-pressure steam systems across power plants, refineries, and chemical processing facilities. Engineered in strict compliance with ASME B16.34 and API 600, our steam gate valves feature pressure seal bonnets and stellite hardfaced seating to eliminate thermal binding, body-bonnet leakage, and steam erosion under extreme pressure-temperature cycling.
Technical Specifications
|
Parameter |
Specification & Applicable Standards |
|
Product Type |
High Pressure Steam Gate Valve (Severe Service) |
|
Design Standards |
API 600, ASME B16.34, BS 1414, ISO 10434 |
|
Pressure Ratings |
ASME Class 600, 900, 1500, 2500, 4500 / PN100 - PN760 |
|
Nominal Sizes |
2" to 36" (DN50 - DN900) |
|
Valve Construction |
Flexible Wedge Gate, Rising Stem, Outside Screw & Yoke (OS&Y) |
|
Body & Bonnet Materials |
Carbon Steel: ASTM A216 WCB / WCC Alloy Steel: ASTM A217 WC6, WC9, C12A (F91 for ultra-supercritical steam) Stainless Steel: ASTM A351 CF8M / C12 |
|
Trim & Seating |
API Trim #5 (Full Stellite #6 hardfacing) / Trim #8 / Custom |
|
Bonnet Configuration |
Pressure Seal Bonnet (recommended for Class 900+), Bolted Bonnet |
|
Stem & Packing |
Die-formed flexible graphite packing with live-loading springs (Anti-extrusion rings included) |
|
End Connections |
Butt-Weld (BW to ASME B16.25), Flanged (RTJ / RF to ASME B16.5) |
|
Operation Options |
Handwheel, Bevel Gearbox, Electric Actuator (AUMA, Rotork), Pneumatic Actuator |
|
Fugitive Emissions |
Compliant with ISO 15848-1 Class AH and API 624 |
|
Pressure & Leakage Test |
API 598, ISO 5208, ASME B16.34 |
|
Quality & Certification |
ISO 9001, CE-PED 2014/68/EU, API 600 Monogram, SIL 3, EN 10204 3.1 / 3.2 |
Key Features & Critical Engineering Solves
Thermal Binding Prevention: Precision-machined flexible wedge mechanism absorbs thermal expansion during rapid steam startup and cooldown, preventing gate jamming.
Pressure Seal Body-Bonnet Joint: Self-tightening pressure seal gasket design ensures that as internal steam pressure increases, the bonnet seal tightens, eliminating joint leaks common in bolted bonnets.
Erosion-Resistant Stellite Overlay: Valve seats and wedge seating surfaces are overlaid with Cobalt-base alloy (Stellite No. 6) to withstand high-velocity steam wire-drawing and particle erosion.
Low-Emissions Stem Sealing: Pre-compressed flexible graphite packing rings with anti-extrusion braided graphite end-rings ensure zero steam leakage and extended service life.
Full-Bore Flow Passage: Minimizes pressure drop and flow turbulence across the valve body when fully open.
Valve Selection & Material Matrix
|
Operating Temperature |
Recommended Body Material |
Pressure Rating Recommendation |
Recommended Bonnet Type |
|
Up to 425°C (797°F) |
ASTM A216 WCB (Carbon Steel) |
ASME Class 600 - 900 |
Bolted Bonnet or Pressure Seal |
|
425°C to 540°C (1004°F) |
ASTM A217 WC6 / WC9 (Cr-Mo Alloy) |
ASME Class 900 - 1500 |
Pressure Seal Bonnet |
|
Up to 600°C+ (1112°F+) |
ASTM A217 C12A / F91 (Creep Resistant) |
ASME Class 1500 - 4500 |
Pressure Seal Bonnet |
Target Applications
Power Generation: Main steam isolation, cold/hot reheat isolation, boiler feed lines, turbine bypass isolation, and steam header valves.
Boiler & Utility Networks: High-pressure steam drum outlets, superheater / reheater isolation, and auxiliary steam headers.
Petrochemical & Refining: Process steam heating loops, hydrocracker steam supply, and high-temperature utility lines.
Quality Assurance & Inspection Control
Material Traceability: EN 10204 3.1 / 3.2 Material Test Certificates (MTC) supplied for all pressure-retaining components.
Non-Destructive Testing (NDT): Radiographic Testing (RT) or Ultrasonic Testing (UT) on pressure castings, plus Magnetic Particle (MT) or Liquid Penetrant (PT) inspection on weld overlay seating surfaces.
Pressure Testing: Hydrostatic shell test (1.5x design pressure) and high-pressure closure seat test (1.1x design pressure) per API 598.
Functional Testing: Full stroke operation check with motorized actuators under simulated pressure load.
RFQ Checklist for Purchasing & EPC Project Managers
Valve Size & Pressure Class: (e.g., 12" Class 1500 / DN300 PN250)
Operating & Design Conditions: Normal and Maximum Operating Pressure (bar/psi) & Temperature (°C/°F)
Piping & End Connection: Flanged (RTJ/RF) or Butt-Weld (specify pipe Schedule or Wall Thickness)
Body & Trim Material: (e.g., Body A217 WC9, Trim API #5 Stellite)
Operation & Automation: Handwheel, Gearbox, or Electric Actuator (brand/voltage preferences)
Applicable Design & Testing Standards: (e.g., API 600, API 598, ASME B16.34)
Required Documentation & NDT: (e.g., PMI, RT, UT, ISO 15848-1 report)
FAQ
Q: Why is a pressure seal bonnet preferred over a bolted bonnet for high-pressure steam?
A: A Pressure Seal Bonnet utilizes the internal system pressure to create a tighter seal against the body gasket. As steam pressure increases, the sealing force increases proportionally.
Q: How do your high-pressure steam gate valves prevent thermal binding?
A: Thermal binding occurs when a valve is closed while hot and cools down, causing the valve body to contract around the wedge and locking it in place.
Q: What body materials are recommended for supercritical steam temperatures above 550°C?
A: For supercritical and ultra-supercritical steam environments where temperatures exceed 550°C (1022°F), standard carbon steel or basic low-alloy steels suffer from thermal creep degradation.
Q: Can butt-weld end connections be customized to match our specific pipe schedule?
A: Yes. Butt-weld ends are manufactured in accordance with ASME B16.25. During the quotation and technical clarification phase, we request your exact piping Schedule or inner diameter dimensions so the valve end transitions can be custom-machined for seamless field welding.
Q: What non-destructive testing (NDT) reports and quality documents are included with the valve shipment?
A: As standard for severe service valves, every shipment includes EN 10204 3.1 Material Test Certificates (MTC), API 598 Pressure Test Certificates, and Dimensional Inspection Reports.
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