Double Block and Bleed Ball Valve

Technical Summary

Nominal Size: 2” to 48”

Pressure Class: Class 150 to Class 2500

Temperature Range: -29°C to 450°C

Design Standards: API 6D, ASME B16.34

Face to Face: ASME B16.10

Fire Safe: API 607, API 6FA

Inspection and Testing: API 598, API 6D

Construction and Materials

Body and Pressure Retaining Parts

• ASTM A105
• ASTM A216 WCB
• ASTM A351 CF8M
• ASTM A182 F51

Internal Components

• Ball: ASTM A105, ASTM A351 CF8M, ASTM A182 F51
• Stem: ASTM A182 F6a, ASTM A182 F316
• Seat Ring: Stainless Steel / Duplex Stainless Steel

Sealing System

• Seat: Soft seated / Metal seated
• Gasket: Graphite / Spiral wound
• Packing: Graphite

Functional Design

Double Block and Bleed Ball Valve is designed to provide two independent sealing barriers within a single valve body, with an intermediate bleed port for cavity pressure release and sealing verification.

When the valve is in the closed position, the upstream and downstream sealing surfaces isolate line pressure while the bleed connection allows trapped cavity pressure to be vented or monitored. This configuration improves operational safety during maintenance and is widely used in critical isolation service where leakage control and pressure verification are required.

Material and Grade

Standard Materials

Component	Material	Grade	Typical Application
Body	Carbon Steel	ASTM A216 WCB	General industrial and high-pressure service
Body	Stainless Steel	ASTM A351 CF8M	Corrosive and process media
Body	Duplex Stainless Steel	ASTM A182 F51	Offshore and chloride environments
Ball	Stainless Steel	ASTM A351 CF8M	Corrosion resistance and shut-off performance
Stem	Stainless Steel	ASTM A182 F6a / F316	Torque transmission and corrosion resistance
Seat Ring	Stainless Steel / Duplex Stainless Steel	ASTM A182 F316 / F51	Sealing integrity and wear resistance

Extended Materials (On Request)

• Super Duplex Stainless Steel (F53 / F55) for high strength and severe chloride service
• Alloy 20 (CN7M) for acidic chemical applications
• Hastelloy C276 for aggressive chemical service
• Inconel 625 / 718 for high temperature and high-pressure service
• Titanium Grade 2 / Grade 5 for seawater and marine applications

Additional Information

Valve Type	Double Block and Bleed Ball Valve
Mounting	ISO 5211 direct mounting pad
Operation	Manual, Gear Operated, Electric Actuated, Pneumatic Actuated
Body Construction	Bolted Body / Fully Welded Body
Port Configuration	Full Bore / Reduced Bore
Seat Design	DIB-1 / DIB-2 configurations available
Bleed System	Integrated bleed port for cavity pressure release and sealing verification

End Connections

• Flanged as per ASME B16.5 and ASME B16.47
• Butt weld as per ASME B16.25
• Socket weld on request for smaller sizes
• Customized end connections based on project requirement

Applications

• Oil and gas industry: pipeline isolation and critical shut-off service
• Petrochemical industry: hydrocarbon handling and process isolation
• Power generation: high pressure utility and fuel systems
• Chemical processing: hazardous and corrosive media isolation
• Offshore and subsea: compact isolation with pressure verification
• Pipeline infrastructure: cavity bleed and sealing verification in transmission systems