High-Temperature Steam Flanged Forged Steel Lift Check Valve

Specification

TIANYU High-Temperature Steam Flanged Forged Steel Lift Check Valve: Industrial Backflow Prevention Solution

I. Product Overview

TIANYU high-temperature steam flanged forged steel lift check valves are constructed from WCB forged carbon steel, designed to GB/T 12235 and API 594 standards. The valve ensures unidirectional flow through a lift-type disc guided by vertical rods, covering DN15-DN300 (1/2″-12″) with PN16 (1.6MPa) pressure rating and -20℃~425℃ temperature range. Specifically engineered for high-temperature steam, thermal oil, and similar media, it serves petrochemical, power, and heating industrial pipelines.

II. Core Technical Parameters

Specifications & Operating Range
- Nominal Diameter: DN15/20/25/40/50/80/100/150/200/250/300 (1/2″-12″)
- Pressure Class: PN16 (shell test pressure 2.4MPa, sealing test pressure 1.76MPa)
- Temperature Range: -20℃~425℃ (standard), -40℃~550℃ (high-temperature alloy option)
- Media Compatibility: Saturated steam, superheated steam, thermal oil, water, compressed air
Materials & Sealing System
- Body/Bonnet: WCB forged carbon steel (tensile strength ≥485MPa, elongation ≥22%)
- Disc/Seat: WCB with STL alloy overlay (HRC58-62), sealing surface roughness Ra≤0.8μm
- Gasket: Flexible graphite + 304 stainless steel wound gasket (resists 600℃)
- Connection: Flanged (RF face, GB/T 9113-2010/ASME B16.5)
Mechanical Performance
- Opening Pressure: ≤0.05MPa (forward flow resistance)
- Closure Response Time: ≤0.3s (triggered by backflow)
- Water Hammer Resistance: 1000 cycles without damage (ISO 16780)

Product Overview

III. Structural Design & Technical Features

Lift Check Mechanism
- Disc moves along vertical guide rods coaxial with the flow path, sealing specific pressure ≥18MPa for bidirectional bubble-tight performance.
- Guide groove precision ≤0.03mm ensures smooth reset, preventing jamming in fluctuating conditions.
High-Temperature Optimization
- Extended bonnet design (prolongation ≥50mm) reduces heat loss, keeping stem temperature ≤60℃ at 425℃ to prevent packing aging.
- Valve disc spring made of 60Si2Mn alloy steel (quenched & tempered), tension loss ≤5% at 400℃ for low-pressure sealing reliability.
Forging Process Advantages
- Body formed by 3000-ton die forging, eliminating casting porosity, grain size refined to Grade 7, fatigue resistance 40% higher than cast valves.
- Surface sandblasted + epoxy primer (dry film thickness ≥100μm), atmospheric corrosion resistance ≥8 years.

IV. Manufacturing Processes & Quality Control

Precision Machining
- Seat sealing surface CNC ground to flatness ≤0.01mm, red lead test contact rate ≥90%.
- Stem straightness ≤0.02mm/m, coaxiality with packing ≤0.05mm for bias-free operation.
Heat Treatment
- Forged blanks normalized at 920℃ + tempered at 650℃ to eliminate stress, hardness controlled at HB170-210.
- STL alloy overlay aged at 550℃ to avoid welding stress cracks, hardness uniformity deviation ≤±3HRC.
Comprehensive Testing
- Hydrostatic test: 1.5x pressure (30min hold), 1.1x sealing pressure—zero leakage (API 598).
- High-temperature aging: 1000h continuous operation in 425℃ steam, seal wear ≤0.05mm.
- Material traceability: Spectral analysis per heat (C/Si/Mn deviation ≤0.03%), provided with MTR.

Valve Details

V. Core Product Advantages

High-Temperature Steam Adaptability
- Petrochemical cracking units: 425℃ superheated steam, STL seal wear ≤0.1mm/year, 5-year leak-free operation.
- Thermal power plants: PN16 suits 1.6MPa saturated steam, water hammer design reduces pipeline vibration by 60%.
- Food sterilization: Optional 304 stainless steel internals, FDA-compliant, zero condensate contamination.
Full-Life Cost Optimization
- Replaceable seat design shortens on-site maintenance to 2 hours/operation, reduces costs by 50%.
- Maintenance-free cycle reaches 80,000 operations or 5 years, 3x longer than cast iron valves, saving $1200/year per DN100 valve.
Installation & Maintenance Convenience
- Suitable for horizontal/vertical installation (vertical flow upward), flange bolts torqued diagonally in three steps (ASME PCC-1).
- Provides visual installation guides; routine maintenance only requires packing gland check, no special tools needed.

Application

VI. Application Fields & Cases

Refinery atmospheric-vacuum unit: DN200 PN16 check valve at steam ejector outlet, ≤0.5L/h backflow in 400℃ superheated steam after 3 years.
Central heating network: DN150 valve controls 1.6MPa, 200℃ saturated steam, extended bonnet prevents stem frosting in winter.
Pharmaceutical clean steam system: DN80 316 stainless steel valve, SIP-validated, seal roughness Ra≤0.4μm, meets GMP requirements.

VII. Installation & Maintenance Guide

Installation Notes
- Clean pipeline debris before installation; recommend upstream Y-strainer (precision ≥60 mesh).
- Use 35CrMoA alloy bolts for high-temperature applications (torque coefficient 0.15-0.18) to avoid thermal loosening.
Routine Maintenance
- Check disc mobility quarterly; monitor for abnormal noise monthly in high-temperature environments (normal operation is silent).
- Replace packing graphite braid annually, apply high-temperature grease (molybdenum disulfide base, dropping point ≥350℃).
Troubleshooting
- For seal leakage, first check flange bolt preload, then lap disc and seat (1000# abrasive).
- Stem jamming due to high-temperature oxidation requires guide groove cleaning and molybdenum disulfide dry film lubricant application.