Ball Valve Double Ball - Floating DBB Compact Manifold | Neway

Neway Double Ball Floating DBB Compact Manifold

The Neway Double Ball Floating DBB is a compact double block and bleed ball valve manifold for positive isolation in process piping. It covers DN50–DN600 / 2"–24" and pressure ratings ASME Class 150–2500 / PN16–PN420, subject to material, trim and end-connection selection.

Construction and End Connections

The body is available in carbon steel, stainless steel, alloy steel and duplex stainless steel. Flanged ends are supplied as RF or RTJ according to pressure class, piping specification and gasket practice.

• Compact DBB body with two floating ball closures and an intermediate bleed cavity.
• Typical design references: ASME B16.34, ASME B16.5 or B16.47, API 6D where specified.
• Inspection and pressure testing may be specified to API 598, API 6D or project ITP requirements.

DBB Operating Principle

The two-ball arrangement isolates the upstream and downstream sides while the cavity between the seats can be vented or drained. This allows verification of zero pressure before maintenance, sampling, instrument removal or equipment disconnection.

Suitable Media and Operating Conditions

• Hydrocarbons, fuel gas, process gas, condensate and liquid utilities.
• Refinery and petrochemical services with defined pressure boundary requirements.
• Temperature capability depends on body material, seat material and seal selection.
• Seat options may include PTFE, reinforced PTFE, PEEK or metal-seated execution, depending on fluid, temperature, Δp and solids content.

Typical Applications

• Refinery and petrochemical process lines.
• Metering skids, analyzer systems and custody-transfer auxiliary isolation.
• High-pressure equipment isolation before depressurization.
• Instrument take-off points where bleed verification is required.
• Gas, hydrocarbon and utility lines requiring compact DBB installation.

Variant Selection

A double ball DBB manifold provides two independent isolation points in one body. Compared with two separate block valves and a spool bleed arrangement, it reduces flange joints and installation length. Compared with a single ball valve with cavity vent, it provides a more defined upstream/downstream isolation sequence.

Actuation Options

Available with manual gear operator, pneumatic actuator, electric actuator or hydraulic actuator. Actuator sizing shall consider maximum differential pressure, seat material, safety factor, operating frequency and fail-safe position where required.

Selection Data Required

• Line size, ASME class or PN rating.
• Body and trim material compatibility with the process fluid.
• RF or RTJ flange facing and applicable pipe standard.
• Operating pressure, temperature range and maximum Δp.
• Bleed port size, drain orientation and connection type.
• Required leakage class, testing standard and certification package.

FAQ

When is DBB used?
When maintenance or disconnection requires isolation on both sides with depressurization of the intermediate cavity.

Is it a replacement for a full isolation procedure?
No. It is a valve arrangement used within the plant isolation and lockout procedure.

What affects leakage performance?
Seat material, pressure, temperature, cleanliness of the medium, cycling frequency and correct actuator torque setting.