Double Block and Bleed (DBB) Needle Valve, Three Handle, 1/2 in NPT, 10,000 psi, Sour Service

The Double Block and Bleed (DBB) Needle Valve, Three Handle, 1/2 in NPT, 10,000 psi, Sour Service is a small-bore instrumentation valve, 1/2 in, 1/2 in NPT Female (process), rated for 10,000 psi. NACE MR0175 / ISO 15156 sour-service compliant.

Double-Block-and-Bleed (DBB) design integrates two block valves and a bleed valve in a single body. Allows positive isolation and bleed-down of the instrumentation line without depressurising the process. Standard configuration for pressure transmitter and gauge installations on safety-critical service.

Construction

• Type: Instrumentation — DBB Needle Valve
• Nominal size: 1/2 in
• Body material: 316 stainless steel — NACE MR0175 compliant
• Stem / trim: 316SS stem + 17-4PH spindle
• Seal / packing: Graphite + Inconel braided packing (sour)
• Inlet: 1/2 in NPT Female (process)
• Outlet: 1/2 in NPT Female (instrument)

Performance

Working pressure 10,000 psi. Hydrotested at 1.5× working pressure. Operating temperature -50°F to +250°F (-46°C to +121°C) per the data plate. NACE MR0175 sour-service compliant — material class EE.

Applications

• Pressure-transmitter installation
• Gauge / instrument calibration tap
• Isolation + bleed for safety-critical
• Sour-gas DBB instrumentation

Compliance

• API 6A / ASME B16.34 instrumentation valve criteria
• NACE MR0175 / ISO 15156 (sour-service)
• Mill test reports per EN 10204 3.1 / 3.2

How to order

Confirm (a) line working pressure and pressure class, (b) end connections (NPT / integral flanged / autoclave compression), (c) service class (standard vs sour, with H₂S partial pressure data for NACE compliance), (d) handle type (T-bar handle / handwheel / locking lever), (e) any required ATEX / IECEx certifications for hazardous-area mounting. Indus quotes ex-Dubai for stock items and ex-works OEM for build-to-order.

Companion products

Pair with matching process-side isolation valve (typically a needle or DBB) and the downstream pressure transmitter / gauge. Indus also supplies impulse-line tubing (1/2" / 1/4" / 3/8" 316SS), fittings (compression and weld), and matching mounting brackets on request.