Control Valve single-seated | Neway

Neway CSS – Single-Seated Control Valve

The Neway CSS is a globe body control valve with a single-seated plug, designed for straight-travel flow control in liquids, gases, and steam. It serves as a final control element in pressure, flow, level, or temperature loops, primarily used in petroleum, chemical, metallurgy, LNG, shipbuilding, power, and building material applications.

Construction Range

The series covers 3/4"–12" / DN20–DN300, with a pressure rating of ASME Class 150–2500 / PN16–PN420. Bodies are available in carbon steel, stainless steel, alloy steel, and duplex stainless steel, with corresponding trim materials from stainless, alloy steel, or duplex materials, depending on media and corrosion.

Trim, Flow Characteristics, and Leakage

The single-seat trim is selected for good seat tightness and stable control at medium or high Δp. Available characteristics include:

• equal percentage
• linear
• quick open

The rangeability is 50:1. Seat leakage is defined by FCI 70-2, with Class IV, V, or VI, where Class VI requires a soft seat. Soft seat selection should consider temperature, chemical compatibility, and differential pressure.

Connections and Temperature

Connections include FF, RF, RTJ, LF, and butt weld. Face-to-face dimensions are per ISA S75.03 for ANSI Class 150–600 and ISA S75.16 for ANSI Class 900–2500. The temperature range is from -196°C to +538°C, with standard, extension, or low-temperature bonnet options.

Actuation

The valve can be paired with pneumatic actuators from the PDL / PCL series or electric actuators such as AUMA and ROTORK. Final selection depends on required thrust, fail-open/fail-close position, Δp at closure, and available instrument air pressure.

FAQ

When to choose single-seated over cage-guided?
When seat tightness is a priority and Δp does not require balanced cage trim.

Sizing considerations: media, flow rate, P1/P2, temperature, Cv/Kv, leakage class, materials, actuator type, and fail-safe position.