Control Valve bellow seal cage-guided | Neway

Neway CBC – Cage-guided Control Valve with Bellows

The Neway CBC is a straight-travel globe valve featuring cage-guided trim and a metal bellows seal to minimize external leakage from the stem. It is utilized in flow, pressure, level, or temperature control loops where low fugitive leakage is required compared to standard packing.

Construction Range

The series covers 1-1/2"–12" / DN40–DN300, with a pressure rating of ASME Class 150–1500 / PN16–PN250. Bodies are available in carbon steel, stainless steel, alloy steel, and duplex stainless steel. Bellows materials include 304, 316, 316Ti, and Inconel, selected based on media, temperature, and operational cycles.

Trim and Control Function

The cage-guided trim provides plug guidance via the cage, reducing lateral forces on the stem in throttling service. Available characteristics include equal percentage, linear, and quick open, with a rangeability of 50:1. For high Δp applications, confirm if the trim is balanced or features anti-noise/anti-cavitation design.

Sealing and Standards

Seat leakage is defined per FCI 70-2, with available classes IV, V, and VI; Class VI requires a soft seat and compatibility checks for temperature, chemical effects, and Δp. Design follows IEC 60534.

Connections and Actuation

Connections include FF, RF, RTJ, LF, and BW. Dimensions are per ISA S75.03 for Class 150–600 and ISA S75.16 for Class 900–1500. The valve pairs with pneumatic PDL/PCL or electric actuators AUMA / ROTORK.

CBC vs. CSC / CBS

• CSC: Cage-guided without bellows, for general throttling service.
• CBS: Bellow seal with single-seat trim.
• CBC: Cage-guided with bellows, for combined Δp control and external leakage limitation.

FAQ

When to choose CBC?
For toxic, volatile, thermal, or corrosive media where bellows and stable plug guidance are required.

Selection Criteria: Media, flow, P1/P2, temperature, Cv/Kv, leakage class, bellows material, fail-safe position, and available actuator thrust.