Product Bulletin TBX Valve

TBX Valve			Tables Figures Coefficients Print Version Collapse Expand

Design TBX Steam Conditioning Valve

TBX Valve Description The TBX Steam Conditioning Valve (figure 1) is designed to handle the most severe applications in today's cycling power plants as well as provide precise pressure and temperature control for process applications. The Design TBX incorporates over 20 years of steam conditioning experience and product development. The valve body is designed with the latest finite element analysis (FEA) and computational fluid dynamics (CFD) tools to optimize performance and reliability for demanding steam systems.
The TBX valve is a flow up design that provides the ultimate combination of performance and maintainability (see figure 3). The TBX valve incorporates low noise Whisper Trim® technology. The simplified trim configuration is thermally compensated to handle rapid changes in temperatures, as expected during a turbine trip, without any sticking or binding.
Water atomization and vaporization are key elements in any steam conditioning application. The TBX design incorporates a spraywater manifold of variable geometry Type AF nozzles that produce an optimized spray pattern over a wide operating range. These nozzles are strategically placed to achieve optimal mixing and quick vaporization at all flowing conditions (see figure 3). Years of research in spray atomization and vaporization were key to optimizing the water injection system. Extensive use of CFD analysis, in addition to field performance feedback, was used to validate spray system enhancements.

Note
Neither Emerson, Emerson Process Management, nor any of their affiliated entities assumes responsibility for the selection, use and maintenance of any product. Responsibility for the selection, use, and maintenance of any product remains with the purchaser and end-user.

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Whisper Trim®, and WhisperFlo® Cages To help attenuate aerodynamic noise in gaseous service, Whisper Trim III cages are available with Design TBX control valves.
WhisperFlo cages (figure 2) are also available to attenuate aerodynamic noise in gaseous service. Contact your Emerson Process ManagementTM sales office for more information.

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Features

Total Steam Control—Combines pressure and temperature control in a single valve.
Full Pressure Drop Capability—Rugged Design TBX is capable of handling full pressure drop of main steam.
Noise Attenuation—Whisper III and WhisperFlo trim cages are available and result in reduced noise for large steam flow and high pressure drop.
High Temperature Capability with Standard Class V Shutoff—Use of the patented Fisher® Bore Seal trim gives capability of Class V shutoff as a standard up to 593°C (1100°F). This unique balanced trim is field-proven. See figure 7.
Forged Valve Body—FEA designed valve body can handle the most demanding applications without thermal stress problems.
Flow Up Angle—Permits vertical stem orientation for ease of maintenance in most applications.
Thermally Compensated Trim—The cage is case-hardened for maximum life and is allowed to grow during thermally induced excursions. The plug is continuously guided and employs cobalt-based overlays for guide bands and tight metal-to-metal shutoff against the seat.
Easy Maintenance Seat Ring—No bolting or gaskets used in the flow stream. Welded design provides Class V shutoff and long life. Deep Alloy 6 overlay can be refinished multiple times to maintain tight shutoff.
Spiral-Wound Gaskets for Excellent Bonnet Sealing Under All Service Conditions—Premium gaskets provided with N06600 windings and Graphite filler material.
Precise Spraywater Injection—CFD designed spray manifold determines water injection point and insertion depth to maximize mixing and quick vaporization.
High Turndown—Standard trim control rangeability is 50:1. Special construction can provide up to 75:1 turndown.
Quick Stroking Actuation—High performance pneumatic piston actuators with FIELDVUE® digital valve controllers can achieve full stroke in less than 2 seconds while still maintaining highly accurate step response.
Performance Diagnostics—With the self-diagnostic capability, questions can be answered about a valve's performance, without pulling the valve from the line. The present valve/actuator signature (seat load, friction, etc.) can be compared against previously stored signatures to discover performance changes before they cause process control problems.

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Options

Blowdown Trim—Protects the working trim and machined surfaces of the valve body during steam blow.
Hydro-Plug— Provides a convenient way to establish hydrotest boundaries associated with using a split pressure class valve.
Split Functionality—When piping dictates, the TBX valve can be provided as separate components allowing the pressure control in the valve body and separate temperature reduction downstream in a steam cooler.
Commissioning Service—Proper installation of blowdown trim and hydro-plug fixtures, along with reassembly and calibration of turbine bypass valves, is critical for the valves to be ready for service when needed. Let skilled Emerson Process Management technicians take care of this vital commissioning service to protect this very important plant asset.
Diagnostic Services—The Emerson Process Management Diagnostic Services Group delivers world class services and innovative technologies for top performance of critical service valves and other production assets.

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Design TBX Steam Cooler The Steam Cooler (figure 4) is normally used when an application requires a separation of the pressure reduction and desuperheating functions. The Steam Cooler is equipped with a water supply manifold. The manifold (multiple manifolds are also possible) provides cooling water flow to a number of individual spray nozzles installed in the pipe wall of the outlet section. The result is a fine spray injected radially into the high turbulence of the axial steam flow. The combination of large surface area contact of the water and high turbulence in the steam make for very efficient mixing and rapid vaporization.

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Design TBX Steam Spargers Whisper Trim Steam Spargers (figure 6) and WhisperFlo Steam Spargers (figure 5) are pressure-reducing devices used to safely discharge steam into a condenser or turbine exhaust duct. In addition, the Steam Sparger provides backpressure to the turbine bypass valve, limits steam velocity, and allows reduced pipe size between the bypass valve and sparger. The design of the sparger is critical to a properly functioning turbine bypass system. To address flow-induced noise, these steam spargers employ Whisper Trim technology and for the most stringent requirements, WhisperFlo technology is employed. The sparger design and installation are both key elements when considering total system noise.

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System Level Noise Today's power plants must comply with strict noise limitations, especially those that are located close to residential areas. Satisfying a low fence line noise requirement requires a complete understanding of the system and how individual components can affect the total noise transmitted to the plant boundary. Extensive steam conditioning noise research has been conducted at the Marshalltown research facility, resulting in a new understanding of the impact of sparger installations in turbine exhaust ducts. Testing has revealed critical spatial relationships of multiple spargers that must be maintained to prevent noise generation. This knowledge, together with the application of low noise technology trims and pressure reducing devices, allows the Emerson Process Management research facility to accurately predict the system noise level.

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Physical Specifications

End Connection Sizes(1)

■NPS 6x8(2), ■NPS 8x12, ■NPS 10x16, ■NPS 12x18, ■NPS 12x20, ■NPS 16x24, ■NPS 20x30, and ■NPS 24x36

End Connection Types

■ASME Buttweld (all sizes)
■ASME Raised Face Flanges (all sizes)

Configuration

Angle Pattern (Flow Up)

Valve Body Ratings(3)

See table 9

Maximum Pressure Drop(1)

Valve with Whisper Trim III Cage: ■ 0.6 ∆P/P1 maximum for level A1
■ 0.75 ∆P/P1 maximum for levels B1 and B3
■ 0.85 ∆P/P1 maximum for level C3
■ 0.99 ∆P/P1 maximum for level D3
Valve with WhisperFlo Trim: ■ If greater than 0.9 ∆P/P1, consult your Emerson Process Management sales office

Flow Characteristics(5)

Whisper Trim III Cages: Linear

Flow Direction

Whisper Trim III Cage: Flow up

Port Diameter and Maximum Travel

See table 9

Bonnet Type

Bolted

Shutoff Classifications per ANSI/FCI 70-2 and IEC 60534-4

■Class V (standard)
■Class V (standard) (Whisper Trim III)
■Class V (standard) (WhisperFlo)

Trim Characteristics

■Linear (standard)
■Special

1. Standard end connection sizes. Alternate inlet and outlet sizes available for each valve body size to match piping requirements.
2. Values given are Inlet versus Outlet, i.e. 6x8 is an NPS 6 inlet and an NPS 8 outlet.
3. Not all valve sizes are available in all pressure ratings.

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Material Specifications

Body/Bonnet

■SA105 (Carbon Steel)
■SA182 Grade F22 (2.25Cr-1Mo)
■SA182 Grade F91 (9Cr-1Mo-V)

Bonnet Bolting

■SA105 Valve Body — SA193 Grade B7 up to 427°C (800°F)
■SA182 Grade F22 Valve Body
— SA193 Grade B16 up to 524°C (975°F), N07718 above 524°C (975°F)
■SA182 Grade F91 Valve Body
— SA193 Grade B16 up to 524°C (975°F), N07718 above 524°C (975°F)

Control Plug

■F22 with Alloy 6 guiding and seating surfaces(1) ■CF8M or S31600 Alloy 6 guiding and seating surfaces(2)

Stem

SA479 Type S20910 (SA105 and SA182 Grade F22 valve bodies)
A565 Grade 616 (SA182 Grade F91 valve bodies)

Cage

■SA182 Grade F22 Nitrided(1) ■S31603 (316L) or 316H chrome-coated cage

Seat

■SA105 Valve Body -- Carbon Steel with Alloy 6 Seating Surface
■SA182 Grade F22 Valve Body -- F22 with Alloy 6 Seating Surface
■SA182 Grade F91 Valve Body -- F91 with Alloy 6 Seating Surface

Piston Rings

Alloy 6 with N07750 Expander

Gaskets

N06600/Graphite

Packing

Graphite/Flexible Graphite

Nozzles

S41000 SST

1. For Whisper III constructions.
2. For WhisperFlo constructions.

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Bore Seal Trim TBX valves provide Class V leakage as a standard. The design employs a variation of the proven C-sealTM trim with enhancements for use with the TBX hung cage. The new sealing design is called Bore Seal trim (figure 7). In the Bore Seal trim, the primary plug-to-seat interface is a metal-to-metal line contact while the secondary metallic seal engages a controlled bore region in the cage when the plug is seated. During modulation, the secondary seal does not contact the upper cage wall and the controlled bore region remains protected, which extends the shutoff life of the valve.

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Table

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