Control Valve

manipulates a flowing fluid, such as gas, steam, water, or chemical compounds, to compensate for the load disturbance and keep the regulated process variable as close as possible to the desired set point

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About GAZAR Control Valve

Performance and safety are two of the key concerns in plants today. Since control valves are the only devices in the control loop that actually move to adjust the process, their performance is fundamental. If they don’t perform properly, you can’t meet production schedules and maintain product quality. GAZAR control valve (Globe, Rotary) manipulates a flowing fluid, such as gas, steam, water, or chemical compounds, to compensate for the load disturbance and keep the regulated process variable as close as possible to the desired set point. The control valve assembly typically consists of the valve body, the internal trim parts, an actuator to provide the motive power to operate the valve, and a variety of additional valve accessories, which can include positioners, transducers, supply pressure regulators, manual operators, or limit switches.

GAZAR Globe Control Valve

Our control valves are available in a variety of sizes (NPS ½ thru 24) and provide users with performance and flexibility. They can help solve an array of application needs from big to small, hot to cold, general to severe. GAZAR globe control valves have a selection of valve cages or plugs that can be interchanged to modify the inherent flow characteristic to linear, equal percentage, or quick opening to meet capacity demands.

GAZAR Rotary Control Valves

Rotary control valves generally have much higher maximum capacity than globe valves for a given body size. This fact makes rotary control valves attractive in applications where the pressure drop is rather small. Rotary control valves include ball, high-performance butterfly (used in throttling applications requiring large flow capacities (from NPS 2 to 72)).

Actuator for Control Valve

Pneumatically-operated control valve actuators are the most popular type in use, but electric, hydraulic, and manual actuators are also widely used. The spring-and-diaphragm pneumatic actuator is most commonly specified due to its dependability and simplicity of design. Pneumatically-operated piston actuators provide high stem force output for demanding service conditions. Adaptations of both spring-and-diaphragm and pneumatic piston actuators are available for direct installation on rotary control valves.

Diaphragm Actuators

Pneumatically-operated diaphragm actuators use air supply from controllers, positioners, or other sources, including various style such as:
1. Direct-acting, in which the increasing air pressure pushes the diaphragm down and extends the actuator stem.
2. Reverse-acting, in which the increasing air pressure pushes the diaphragm up and retracts the actuator stem.
3. Reversible, in which actuators can be assembled for either direct or reverse action.
4. Direct-acting unit for rotary valves, in which the increasing air pressure pushes down on the diaphragm, which, depending on orientation of the actuator lever on the valve shaft, may either open or close the valve.

Piston Actuators

Piston actuators are pneumatically operated using high-pressure plant air up to 150 psig (10.3 bar), often eliminating the need for a supply pressure regulator. Various accessories can be incorporated to position a double acting piston in the event of supply pressure failure, including pneumatic trip valves and lock-up systems.

Manual Actuators

Manual actuators are useful where automatic control is not required, but where ease of operation and good manual control is still necessary.
They are often used to actuate the bypass valve in a three-valve bypass loop around control valves for manual control of the process during maintenance or shut down of the automatic system.

Electric Actuators

Electric actuator designs use an electric motor and some form of gear reduction to move the valve plug. While electric actuators have traditionally been limited to on/off operation, some are now capable of continuous control. The use of brushless motors in electric actuators can reduce or eliminate motor burnout associated with turning the motor on and off rapidly. The initial purchase price still tends to remain above that of pneumatic actuation.

Integrated Accessory Attachment

Eliminates external tubing reduced height and weight
Entire actuator top works can be rotated 360° without disassembly

Self-adjusting PTFE V-ring Packing

Maintenance-free design
Low friction
Roller burnished stem reduces friction external leakage, and maximizes packing life beyond what basic polishing can offer from competitors.
Double wall design
Small valve travel results in a long bellows life
Modular design allows for the addition or removal of assembly bellows in the field
Straight Thread Seat Design No cage, gaskets or seals required trim Fewer spare parts required for maintenance Easy removal even after many years of service.
Various Noise Attenuation Options Flow Divider I, II, & III (Gases/Vapors) Anti-Cavitation Trims (Liquids) Optional downstream orifice plates

Rolling Diaphragm

Greatly reduces diaphragm wear compared to Stretching diaphragm design used by competitors Diaphragm design results in very small external air loss

Single Bonnet/Yoke Design

Actuator removal without the need to open the valve Bonnet and body of the valve always have same metallurgy Fewer components results in a lower profile valve

Low Lying Guide Bushing

Ensures precise plug alignment for our stem guided

Multiple Plug Designs

Parabolic: Cost effective & debris friendly
V-Port: Reduced vibration & debris friendly
Perforated: Vibration reduction and flow dispersion

GAZAR Internal Strength

Trim For Every Application Obstacles hindering accurate process control can be numerous. GAZAR Control Valves comes equipped with a wide range of available trim options to overcome difficult to control applications.
1. Parabolic Plug 2. V V-Port Guided Plug 3. V Perforated Plug 4. V Multi-Stage Trim 5. Noise Attenuation Trim

Noise Reduction

When not getting noticed is a good thing

A flow divider is an optional internal device used with gases and vapors to help reduce the sound pressure level (SPL) of a valve. By creating an additional stage of pressure reduction inside the valve, it breaks a single large flow stream into multiple smaller flow streams, resulting in reduced noise emissions.
1. Steam Service 2. PSA (Pressure-Swing Adsorption) 3. Toxic and Corrosive Processes 4. Cryogenics

Technical Details

Valve Size: NPS 1/2 to 24 | Pressure Rating: ANSI Class 150 to 1500 | End Connection: Flanged: All ANSI Versions, Welding Ends: According to ANSI B16.25, Threated Ends: Up to NPS 2, ANSI 250 class only | Materials: Carbon Steel (A216 WCC, A352 LCC, & A217WC6) | Temperature Range: -325 to 842°F (-196 to 450°C) | Internal Leakage Rate: Class IV,V, or VI according to ANSI/FCI 70-2 and IEC 60534-4 | Extensions: Standard/Insulating/Bellows Seal | Packing: Spring-Loaded Low Emission V-ring Packing

GAZAR Control Valve Sizing

Control valves handle all kinds of fluids at temperatures from the cryogenic range to well over 538°C (1000°F). Selection of a control valve body assembly requires particular consideration to provide the best available combination of valve body style, material, and trim construction design for the intended service.
Capacity requirements and system operating pressure ranges also must be considered in selecting a control valve to ensure satisfactory operation without undue initial expense. Following information be provided for any set of conditions deemed important:
Type of fluid to be controlled
Temperature of fluid
Viscosity of fluid
Concentrations of all constituents including trace impurities
Process conditions during startup, normal operations, and shutdowns
Chemical cleaning that may occur periodically
Specific gravity or density of fluid
Fluid flow rate I
Inlet pressure at valve
Outlet pressure or pressure drop
Maximum permissible noise level, if pertinent, and the measurement reference point
Degrees of superheat or existence of flashing, if known
Inlet and outlet pipeline size and schedule
Special tagging information required
Cast body material (ASTM A216 grade WCC, ASTM A217 grade WC9, ASTM A351 CF8M, etc.)
End connections and valve rating (screwed, Class 600 RF flanged, Class 1500 RTJ flanges, etc.)
Action desired on air failure (valve to open, close, or retain last controlled position)
Instrument air supply available
Instrument signal (3 to 15 psig, 4 to 20 mA, HART, etc.)

Control Valve, Design BF

Specifications: Globe-Style, Economical | Stem Guide Equal | Percentage – Flow Up | Bullet Form in Steel or Stainless Steel Bodies | Equal to Maximum Inlet pressure 1500 Psig From (-20 to 450°F) | Screwed or Socket weld End Connections

Description
Standard
NACE-MR0175
NACE-MR0175
Body
WCB
WCB
316 SS
Bonnet
WCB
WCB
316 SS
Stem
316 SS
316 SS
316 SS
Seat Ring
316 SS
316 SS
316 SS
Valve Plug
316 SS
316 SS
316 SS
Guide Bushing
17-4 PH SS
17-4 PH SS
Hastelloy C

Control Valve, Design BT

Specifications: Bodies are Globe-Style Valves | Full Capacity Trim: Quick Opening, Linear or Equal Percentage | Bullet Type, stem guide

Description
Standard
NACE-MR0175
NACE-MR0175
Body
Cast Iron
WCB Steel
31 6 SST (CF8M)
Cage
17-4 PH SST
316 SS
316 SS
Seat Ring
410 or 416 SS (Hardened)
316 SS / Alloy 6 Seat
316 SS
Valve Plug
416 SS (Hardened)
316 SS / Alloy 6 Seat
316 SS
Guide Bushing
17-4 PH SST
Alloy 6
Alloy 6

C-Type Ball Valve

Specifications: Modified equal percentage | PTFE Packing: -46 to 232 C | Graphite Ribbon Packing: -198 to 427 C | -46 to 260 C, 150 & 300 LB

Description
Standard
NACE-MR0175
Stainless steel
Body
ASTM A216 Gr. WCC
ASTM A216 Gr. WCC
ASTM A351 Gr.CF8M
V-notch Ball
ASTM A351 Gr.CF8M
ASTM A351 Gr.CF8M
ASTM A351 Gr.CF8M
Shaft
S20910/Monel
S20910
17-4PH
Bearing
Peek/PTFE
PEEK/PTFE
PEEK/PTFE
Valve Shaft
PTFE
PTFE
PTFE

Eccentric Ball Valves

Specifications: Modified linear | PTFE V-ring: –198 to 232 C | Graphite: –198 to 425 C,150 & 300 LB

Description
Standard
NACE-MR0175
Stainless steel
Body
ASTM A216 Gr. WCC
ASTM A216 Gr. WCC
ASTM A351 Gr.CF8M
Valve Plug
Chrome-Plated 316 SS
Alloy 6
316 SS
Shaft
316 SS
316 SS
316 SS
Guide Bushing
440 SS/Alloy 6
316 SS
PEEK/PTFE/Alloy 6
Valve Shaft
S20910 (Nitronic 50)
S20910 (Nitronic 50)
S20910 (Nitronic 50)

Control Valve, Design HP

Specifications: High-Pressure, Globe Valve | Metal Seats, Cage Guide | 2160 psi (149 bar) For Two | Stage Cage and 3000 psi (207 bar) | For Three-Stage Cage | Equal percentage,Modified Equal Percentage, Linear

Description
Standard
NACE-MR0175
Stainless steel
Body
WCB steel
WCB steel
316 Stainless Steel
Valve Plug
442 Stainless Steel
17-4PH stainless steel with Alloy 6
316 Stainless Steel with Alloy 6
Cage
17-4PH Stainless steel
17-4PH Stainless steel
316 Stainless Steel Electrolyzed
Seat Ring
416 Stainless Steel
Alloy 6
Alloy 6
Seat Ring Retainer
416 Stainless Steel
Inconel 718 Heat Treated Electrolyzed
Inconel 718 Heat Treated Electrolyzed

Control Valve, Design PT

Specifications: Globe Style | Cage Guide | Quick- Opening, Linear, Equal Percentage | Anti-Noise: Always Up | Anti-Cavitation: Always Down | High-temperature | High-Pressure is available too

Description
Standard
NACE-MR0175
Stainless steel
Body
WCB Carbon steel
LCB Carbon Steel
316 Stainless Steel
Valve Plug
416 Stainless Steel
420 Stainless Steel
316 Stainless Steel
Cage
17-4PH Stainless steel
17-4PH Stainless steel
316 Stainless Steel with Electroless Nickel
Disk Seat
316 Stainless Steel
316 Stainless Steel
Seat Ring
410 or 416 Stainless Steel
17-4PH Stainless steel
316 Stainless Steel