Standard Control Valve

Principal of Operation                                                       

Design GX Principal of Operation - Actuator Air Supply

Integrated Air Supply. When mounted with the DVC2000 Series digital valve controller, the Design GX uses an

integrated actuator air supply system.

In the air-to-open construction, air is supplied to the lower actuator casing via a port on the actuator yoke

face -- no tubing is required.

In the air-to-close configuration, air is supplied to the upper casing via tubing.

The Design GX Control Valve

The Design GX is a single port, flow-up globe style valve that offers stem-guided, port-guided, and balanced trim

with a screwed-in seat ring (see table below for a description of trim style availability). Each valve size offers an

unbalanced plug design, which eliminates dead spaces where fluid polymerization might occur.

Sizes DN80, 100, and 150 (3-, 4-, and 6-inch) also offer balanced trim to reduce actuator thrust requirements.

The Design GX incorporates a clamped bonnet and an easy-to-adjust screwed packing follower. The plug and

stem are a rugged, one-piece welded assembly.

The standard construction incorporates metal-to-metal seating, with a PTFE soft seat option for Class VI shutoff.

Class V shutoff is available with metal trim. Hardened trim with stellite overlay is available for erosive service, as well.

PTFE V-ring stem packing is standard with the GX.

The live-loaded system provides excellent stem sealing and extended service life. Live-loaded graphite ULF packing

and extension bonnets are available for high temperature applications. Both linear and equal percentage flow

characteristics are available in full port and restricted trim. Micro-FlowTM is available for applications requiring low flow

control capability.

Standard valve body materials are carbon steel and stainless steel. Alloy materials are available for valve body sizes

DN 15 through DN 100 (0.5 through 4-inch) for highly corrosive applications.

Modular Design                                                       

Modular Design

The design architecture has been
optimized to maximize the use of common parts across sizes.

The actuator stem and stem connector are used across all GX sizes.

Only one set of springs is used

in each of the two actuator sizes 225and 750.

Size 1200 actuators have two sets of springs, one for 40 mm travel and one for 60 mm
travel.

The plug/stem assemblies and packing sets are common across several sizes, as well.

Anti-corrosion Finish                                                       

Design GX Control Valve Specifications and Materials of Construction

No actuator sizing                                                       

Compact Actuator Design

The multi-spring GX actuator is compact and field-reversible. (No extra parts are required to reverse the fail-action).

The GX design has been optimized to eliminate complicated actuator sizing procedures - once the valve body
and port size are selected, the actuator

size is fixed.

The Design GX uses a multi-spring, pneumatic

diaphragm actuator. It is capable of air supply

pressures to 6.0 barg (87 psig), allowing valve

shutoff at high pressure drops.

The Design GX product selection system
automatically matches the actuator to the valve,
eliminating the need for complex actuator sizing
procedures.

The multiple spring design provides the preload,
eliminating the need for bench set adjustment. The
actuator is available in spring-to-open and
spring-to-close configurations (air-to-close and
air-to-open) and is field-reversible.

The GX actuator can be used for throttling or on-off
service.

The Design GX is available with the integrated DVC2000 Series digital valve controller. Other digital and analog

positioners are available, as well as optional solenoids and limit switches.

Actuator Selection

With the Design GX, actuator selection has never been easier. Once the valve size and port diameter have been determined,

the actuator is automatically selected. No spring selection or bench set calculations are required.

The following tables provide the maximum allowable pressure drops for the Design GX.The majority of GX constructions

(both air-to-open and air-to-close) are rated to a full pressure class shutoff capability of 51.7 bar (750 psi) for a 4 to 6 bar

(58 to 87 psig) actuator air supply.

Actuator Pressure Drop Capability For S31603 Trim (with S31603 or S20910 stem) in Standard,

Extension, and Bellows Bonnet Constructions with 4-6 bar (58-87 psi) Actuator Air Supply(1, 2, 3)

DVC 2000                                                       

Integrated Mounting

The DVC2000 digital valve controller integrally mounts to the Design GX actuator, eliminating the need for mounting brackets.

The DVC2000 transmits a pneumatic signal to the actuator casing

via an air passage in the yoke leg, causing the valve to stroke.

This eliminates the need for positioner-to-actuator tubing in the air-to-open (spring-to-close) configuration.

The DVC2000 mounting interface is identical on both sides of the

actuator yoke for valve body sizes DN 15 through DN 100 (0.5 inch through 4-inch).

This symmetrical design allows the DVC2000 to be easily moved

from one side of the valve to the other without the need to rotate the actuator. The DN 150 (6-inch) yoke is not symmetrical.

The DVC2000 digital valve controller offers as standard a non-contacting valve position feedback system.

This is a true linkage-less design, which uses no levers and no touching parts between the valve stem and the positioner.

 The interface supports multiple languages, including German, French, Italian, Spanish, Chinese, Japanese, and English.

The Design GX is available with the DVC2000 Series digital valve controller. The DVC2000 is easy to use, compact, and designed

for easy mounting.

It converts a 4-20 mA input signal into a pneumatic output signal,

which feeds the control valve actuator. Instrument setup is

performed with a push button and liquid crystal display (LCD)
interface. This interface is protected from the environment within

a sealed enclosure.

Intrinsic safety and non-incendive construction is available to CSA,

FM, ATEX, and IEC standards. An optional module provides

integrated limit switches and a position transmitter.

Seat engineered                                                       

Live-loaded Packing

The Design GX comes with live-loaded PTFE V-ring packing as standard. The live-loaded design helps to seal your process

to conserve valuable process fluid, while reducing emissions to the environment.

The long-life and high reliability of the live-loaded system also reduces maintenance costs and process downtime.

For applications exceeding 232°C (450°F), live-loaded ULF (Ultra Low Friction) graphite packing and extension

bonnets are available for all sizes except DN150.

Bellows Extension Bonnet

The Design GX bellows extension bonnet provides reliable and tight stem sealing for those applications where emissions

escaping to the environment cannot be tolerated. The GX bellows is available in SST (1.4571 / 316Ti) or N10276 and

covers a full range of valve sizes from DN 15 through DN 100 (0.5 through 4-inch).

The mechanically-formed metal bellows provides high operating reliability and extended cycle life. The GX bellows design

incorporates a rugged double- or triple-wall construction for added security. Each bellows has been tested with helium

before it leaves the factory.

The GX bellows bonnet comes standard with a live-loaded, PTFE packing system as a security backup. A connection

is provided above the bellows to allow purging or monitoring the integrity of the replaceable bellows.

The GX bellows system has been designed for 100,000 full-travel cycles at maximum allowable pressure

and ambient temperature (20°C [68°F]).

Cycle Life                                                       

Manual Handwheel                                                       

The Design GX is available with an optional, side-mounted manual handwheel. These handwheels provide a robust method of

manually operating the valve in an emergency or upon loss of instrument air.

The GX handwheel will stroke the valve up to 20mm travel,

and is available on the size 225 and 750 actuators.

When mounted to an air-to-close (spring-to-open) actuator,

rotating the handwheel clockwise moves the stem downwards.

When mounted to an air-to-open (spring-to-close) actuator,

turning the handwheel in the clockwise direction causes the

stem to move upwards.

Disengagement of the handwheel to allow automatic operation

is accomplished by simply rewinding the handwheel.

Video