F304L 12″ Bi-Directional Double Block and Bleed Steam Ball Valve

Specification

This ball valve features trunnion mounted configuration, which has two-piece and three-piece valve body structures. The body and bonnet are connected by bolts, and the seal adopts metal to metal seating. It is suitable for long-distance pipelines and general industrial pipelines. Due to its strength and safety, it is suitable for various corrosive and non-corrosive media.

Compared with the floating ball valve, during working, the force generated by the fluid pressure in front of the valve on the ball is all transmitted to the bearing, and the ball will not move to the valve seat, so the valve seat will not bear excessive pressure, so the sealing performance is stable and the service life is long.

Nominal size	2″~24″(DN25~DN1200)
Nominal pressure	Class 150~Class 2500(PN10~PN420)
Standard:	ASME B16.34, API6D, ISO17292
Body material	Carbon steel, Stainless steel, Alloy steel, Duplex stainless steel
End connection	RF, BW, RTJ,
Operation	Manual, Pneumatic, Electric, Hydraulic

Product Overview

TIANYU F304L 12-inch Bi-Directional Double Block and Bleed Steam Ball Valve: The Safety Core for High-Pressure Steam Systems

I. Technical Overview

The TIANYU F304L 12-inch Bi-Directional Double Block and Bleed Steam Ball Valve is a high-performance shut-off device designed for high-pressure steam pipelines. Made of F304L low-carbon stainless steel through integral forging, it features bidirectional sealing and cavity pressure relief, capable of blocking upstream/downstream media and releasing internal pressure simultaneously. Suitable for petrochemical, power, and heating networks, it complies with API 6D, ISO 17292, and ASME B16.34, with a 12-inch (DN300) size, pressure class CLASS 150-900 (PN10-PN150), and temperature resistance of -29℃~450℃ for harsh steam applications.

II. Core Features

(A) Bi-Directional DDB Design

Bidirectional Bubble-Tight Sealing: Independent metal seats with Molon® composite material and spring preloading ensure bidirectional sealing (leakage ≤5×10⁻¹⁰Pa·m³/s), meeting API 598 Class IV. It blocks media under pressure simultaneously;
Automatic Pressure Relief: A central relief port automatically retracts seats to release overpressure, then resets, complying with API 6FA fire safety standards;
Trunnion Mounting: The ball is supported by upper/lower trunnions, reducing stem load by 30% and enhancing sealing stability by 50% under CLASS 900 (PN150) pressure.

(B) Material & High-Temp Compatibility

Component	Material	Key Advantage	Media Compatibility
Body/Ball	F304L SS	Tensile ≥485MPa, intergranular corrosion resistance	Superheated steam, condensate, sulfurous media
Seat	Molon® Composite	-20℃~450℃ resistance, anti-creep wear	High-temperature steam, high-velocity flow
Stem	17-4PH SS	HRC30-35 hardness, blowout-proof (ISO 15761)	Wet steam, high-temperature oxidation
Seals	Flexible Graphite+SS	≤5% compression set, continuous sealing at high temps	Superheated steam (450℃), condensate

(C) Operation & Maintenance

Multi-Drive Options: Standard manual gearbox (≤200N·m), optional pneumatic (≤1.5s response), electric (IP68), or hydraulic actuators for remote control;
Quick-Disassembly Design: Symmetric bolted bonnet allows 20-min seal replacement, improving maintenance efficiency by 40% for online servicing.

III. Technical Specs & Manufacturing

(A) Key Parameters

Pressure/Temp Range:
- Pressure: CLASS 150-900 (PN10-PN150, max 15MPa);
- Temperature: -29℃~450℃ (F304L limit);
Bore & Flow:
- 12-inch full bore (DN300), Cv=180, 25% lower pressure drop than reduced-bore valves;
Testing:
- Hydrostatic: 1.5x pressure (30-min hold);
- Gas-tight: 1.1x pressure (helium, ≤1×10⁻⁹Pa·m³/s);
- Fire test: Complies with API 607, maintaining seal during fires.

(B) Precision Manufacturing

F304L Forging:
- AOD-refined F304L billet (C≤0.03%) forged via 8000-ton press (forging ratio ≥6:1), ASTM No.8+ grain, UT-tested for ≥Φ1.2mm defects;
- Ball ground to ≤0.003mm roundness, ≤0.005mm fit with seats for high-temp precision.
Surface Treatments:
- Electropolished interior (Ra≤0.8μm) reduces steam deposition;
- Passivated exterior (ASTM A967), optional anti-oxidation coating (50μm) for high-temp scale resistance.
Quality Control:
- 100% NDT (UT+MT), RT for critical welds;
- 100,000-cycle testing (450℃ steam), sealing retention ≥95% (Far beyond industry standards 50,000 cycles).

Valve Details

IV. Applications & Industry Value

(A) Typical Uses

Power Steam Systems:
- Main steam pipeline isolation in power plants, F304L lasting 8 years in 540℃ superheated steam, ASME BPVC Section VIII certified;
- District heating network sectioning, bidirectional sealing preventing steam backflow, 90% fewer leakage incidents annually.
Petrochemical:
- High-temperature steam shut-off in ethylene crackers, automatic relief preventing cavity overpressure;
- Refinery atmospheric-vacuum distillation, F304L resisting chloride corrosion for 5+ years in sulfurous steam.
Central Heating:
- 12-inch valve handles 1,200t/h steam flow with ≤0.05MPa drop, 15% higher heating efficiency;
- Heat exchanger steam control, quick-disassembly enabling 15-min online maintenance.

(B) Customer Benefits

Safety Compliance: API 6D, CE-PED, ISO 9001 certified, meeting OSHA and TSG G0001 to reduce compliance risks;
Cost Optimization: Streamlined flow saves 20,000 tons of steam annually, 24-month maintenance cycles cut total cost by 35%;
Customization: Non-standard flanges (DIN/GOST), special coatings (tungsten carbide), and ATEX-explosion proof actuators available.