Double Block & Bleed Monoflange -- Instrument SS316
Technical Datasheet -- Integral DBB Monoflange Valves for Instrument Isolation
Document No.SV-DATA-MFL-001
RevisionA
DateMay 2026
ManufacturerSupreme Valves India, Ahmedabad, Gujarat, India
Instrument double block and bleed (DBB) monoflange valves for primary isolation, secondary isolation, and vent/drain of pressure transmitters, gauges, and sampling systems. Integral two ball valves and one needle valve machined from a single SS316 or duplex stainless steel barstock forging. Compact design replaces three separate valves, eliminating leak paths and reducing weight by 70%. NACE MR0175 sour service standard. Multiple configurations: 2-ball+1-needle (standard DBB), 1-ball+1-needle (SBB), 2-ball+2-needle (DBDB), 3-ball+1-needle (manifold). API 6D / ASME B16.34 / NACE MR0175 compliant.
Technical Specifications
| Parameter | Specification |
|---|
| Product Type | Double Block & Bleed Monoflanges |
| Category | Multi-Port Valves |
| Size Range | 1/2" to 2" (DN15 to DN50) -- instrument process connection: 1/2" NPT female typical; instrument outlet: 1/2" NPT female typical |
| Pressure Rating | Up to 6,000 psi (414 bar) -- standard: 4,500 psi (310 bar) |
| Process Connection | Flanged RF / RTJ per ASME B16.5 Class 150 / 300 / 600 / 900 / 1500, Threaded NPT / BSP, Socket weld, Butt weld |
| Instrument Connection | Threaded NPT / BSP / metric (1/2" typical), Flanged RF (small size), Tube fitting compression (1/4" to 1/2" OD) |
| Body Material | ASTM A182 F316 (SS316 forged barstock) / ASTM A105 (carbon steel forged barstock) / ASTM B564 UNS N04400 (Monel) / Duplex SS ASTM A182 F51 / F53 |
| Ball Valve Trim | SS316 ball with ENP or chrome plating, PTFE/RPTFE seats, SS316 stem with anti-blowout |
| Needle Valve Trim | SS316 precision needle with Stellite 6 tip, integral SS316 seat, PTFE/RPTFE or graphite packing |
| Vent / Drain Connection | Threaded NPT / BSP (1/2" or 3/4" typical) with plug or cap -- can be oriented to process or safe direction |
| Configuration | 2-ball + 1-needle (standard DBB) / 1-ball + 1-needle (single block and bleed) / 2-ball + 2-needle (double block and double bleed) / 3-ball + 1-needle (three-valve manifold) |
| Leakage Class | API 598 / EN 12266-1 Class A -- zero visible leakage for ball and needle valves at rated pressure |
| Temperature Range | -50 deg C to +200 deg C (PTFE seats/packing) -- up to +540 deg C (graphite packing, SS316 body) |
Materials of Construction
| Component | Material |
|---|
| Stainless Steel | ASTM A182 F316 (SS316) forged barstock body, ball, needle, and seat (standard instrument service) |
| Carbon Steel | ASTM A105 forged barstock body (standard industrial, non-corrosive) |
| Nickel Alloy | ASTM B564 UNS N04400 (Monel) body and trim (seawater / reducing acid service) |
| Duplex Stainless Steel | ASTM A182 F51 / F53 (duplex SS) body and trim (sour gas / chloride service per NACE MR0175) |
Testing & Inspection
| Test | Requirement |
|---|
| Testing | Hydrostatic shell test 1.5 x WP per API 598 / EN 12266-1; Seat leakage test per API 598 / EN 12266-1; Functional test -- full stroke, torque; Material certificates per EN 10204 3.1 |
| Certification | ISO 9001:2015 QMS, EN 10204 3.1 material certificates, hydrostatic and seat test reports |
Applicable Standards
| Standard | Description |
|---|
| Design Standard | API 6D (reference for DBB concept), ASME B16.34, NACE MR0175 (standard for sour service), ISO 17292 |
Notes
- Process connection size/rating, instrument connection type, and valve configuration (DBB / SBB / manifold) must be specified by the purchaser.
- For oxygen service (> 21% O2), all components must be degreased and cleaned per ASTM G93 Level 300; PTFE seats and packing required.
- For sour gas service (H2S > 50 ppm), duplex stainless steel (ASTM A182 F51/F53) body and trim per NACE MR0175 is strongly recommended over SS316.
- Vent/drain connection orientation (toward process or safe side) must be specified at order; cannot be changed after manufacture without body modification.
- All valves are manufactured by Supreme Valves India as per our standard specifications.
