High Pressure Stainless Steel Flange Double Block and Bleed Valve DBB Flange Drain Valves

Product Attribute: Connection Form:Flange
Driving Mode:Manual
Nominal Pressure:PN1.0-32.0MPa
Channel:Straight Through Type
Structure:Floating Ball Valve
Type:Floating Ball Valve
Function:Blow-Down Valve, Relief Valve, Atmospheric Valve, Bypass-Valve
Temperature:Normal Temperature
Application:Industrial Usage, Water Industrial Usage, Household Usage
Specification:1/2″~8″, DN15~ DN200

INFO@TYFLUIDGROUP.COM

Specification

TIANYU Industrial Stainless Steel Flange Double Block and Bleed Valve: The Safety-Critical Solution for High-Pressure Fluid Control

I. Technical Overview

The TIANYU Industrial Stainless Steel Flange Double Block and Bleed Valve (DDB Valve) is a safety-rated shut-off device designed for high-pressure pipeline systems. Featuring a floating ball structure and dual seat sealing, it blocks upstream and downstream media simultaneously while relieving cavity pressure. With sizes ranging from 1/2″ to 8″ (DN15-DN200) and pressure ratings of PN1.0-32.0MPa, it suits corrosive media like gas, oil, water, and acid liquids, widely applied in petrochemical, natural gas, and power sectors requiring strict safety isolation.

II. Core Product Features

(A) Double Block and Bleed (DDB) Design

Bidirectional Sealing: Upstream/downstream seats with PTFE+25% carbon fiber ensure bubble-tight sealing (leakage ≤5×10⁻¹⁰Pa·m³/s), complying with ISO 15848-1.
Safety Pressure Relief: A central bleed port releases internal pressure online, eliminating overpressure risks for hot work and pipeline maintenance.
Floating Ball Structure: Unsupported ball self-compresses against seats via medium pressure, enhancing sealing reliability by 30% under high pressure (up to PN32.0MPa).

(B) Material & Application Compatibility

Component	Material	Key Advantage	Media Compatibility
Body/Ball	304/316L SS	Tensile ≥515MPa, resistant to chloride stress corrosion	Acid, seawater, chemical solutions
Seat	PTFE+25% Carbon Fiber	-20℃~260℃ resistance, anti-creep wear	High-viscosity oil, particulate media
Stem	17-4PH Precipitation Hardened SS	HRC30-35 hardness, blowout-proof (ISO 15761)	Wet environments, H₂S-containing gas
Seals	Viton Fluororubber	Chemical resistance, ≤10% compression set	Strong acids, alkalis, solvents

(C) Operation & Maintenance Optimization

Reliable Manual Operation: Standard gearbox handwheel with ≤150N·m torque (DN50), ideal for remote areas or emergency shutdowns without power.
Quick-Disassembly Design: Symmetric bolted bonnet allows 15-min seal replacement, improving maintenance efficiency by 50% for online servicing.

Product Overview

III. Technical Specs & Manufacturing Processes

(A) Key Performance Indicators

Pressure & Temperature Range:
- Pressure: PN1.0-32.0MPa (145-4641PSI);
- Temperature: -20℃~260℃ (optional -196℃ cryogenic or 450℃ high-temperature).
Bore & Flow Resistance:
- Full-bore design with Cv=12-180 (size-dependent), 20% lower pressure drop than reduced-bore valves.
Testing Standards:
- Hydrostatic: 1.5x rated pressure (30-min hold);
- Gas-tight: 1.1x pressure (helium test, leakage ≤1×10⁻⁹Pa·m³/s).

(B) Precision Manufacturing

Stainless Steel Forging:
- Valve bodies forged from AOD-refined SS billets (C≤0.03%) via 800-ton press (forging ratio ≥4:1), achieving ASTM No.8+ grain size.
- Balls ground to ≤0.005mm roundness, ≤0.01mm fit with seats for precision sealing.
Surface Treatments:
- Electropolished interior (Ra≤0.8μm) reduces media deposition;
- Passivated exterior (ASTM A967), optional epoxy coating (200μm, 1000-hr salt spray) for marine use.
Full-Process QC:
- 100% NDT (UT+MT), RT for critical welds;
- 100,000-cycle testing with ≥95% sealing retention (Far beyond industry standards 50,000 cycles).

Valve Details

IV. Applications & Industry Value

(A) Typical Industrial Uses

Oil & Gas Extraction:
- Wellhead main shut-off: 316L sulfur-resistant valves (NACE MR0175) last 8 years in 1500ppm H₂S;
- Pipeline sectioning enables live tapping, reducing downtime losses by 40%.
Chemical Process Control:
- Reactor safety shut-off: PN25.0MPa valves close within ≤2s to prevent backflow;
- Acid transport: 316L+PTFE seals withstand strong acids for 5+ years leak-free.
Power & Environmental Engineering:
- Nuclear auxiliary pipelines: Seismic-proof (IEEE 344 compliant);
- Wastewater treatment: PN16.0MPa valves with wear-resistant seats last 7 years in sandy sewage.

(B) Customer Value Proposition

Safety Compliance: ISO 9001, CE-PED certified, meeting OSHA, API 598 standards to minimize compliance risks.
Cost Optimization: Streamlined flow saves 15% annual pumping energy, 24-month maintenance cycles reduce total cost by 35%.
Customization: Supports non-standard flanges (ANSI/DIN/JIS), special coatings (tungsten carbide), and ATEX-explosion proof actuators.