SEMPELL DEWRANCE CHECK VALVES BLED STEAM
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EMERSON. SEMPELL DEWRANCE CHECK VALVES BLED STEAMCast tilting disk check valve designed specifically for extraction steam and cold reheat non-return applications, utilizing triple offset seating geometry providing reliable and stable operation with positive closure GENERAL APPLICATION Emerson's Sempell Dewrance bled steam check valve has been designed specifically for non-return turbine protection on power generation steam turbines for the following applications: - Bled steam check valves - Extraction steam check valves - Reverse current check valves - Quick close non-return valves - Cold reheat non-return valves - Turbine exhaust Other sizes/pressure classes available on request (up to NPS 48, DN 1200) Emerson.com/FinalControl © 2017 Emerson. All Rights Reserved VCTDS-01396-EN 19/03

SEMPELL DEWRANCE CHECK VALVES BLED STEAM Graphoil gasket/pressure seal bonnet (dependent on) size/pressure. Disc supported in surface treated bearings. Inclined seat and aerodynamic tilting disc gives low pressure drop, and minimum disc travel. Variable seat/disc to suit actual condition for optimum flow characteristics. Hard faced Stellite® or equivalent disc. Internal counterweight to ensure maximum opening position under low flow conditions. No external glands or keyway to inhibit operation. Positive open position stop and aerodynamic disc provides stability over wide range of flow (no...

SEMPELL DEWRANCE CHECK VALVES BLED STEAM INTRODUCTION This range of valves has been specifically designed for installation in bled (extraction) steam lines between steam turbines and feed water heaters but are equally applicable to reheater connections and bleed on pass-out lines in process plants. Their function is to prevent the reverse flow of stored steam and any water from the heater or its bled steam pipe to the turbine. Installation would be in a horizontal pipe as near to the turbine as possible. These valves are free acting whereby the disc moves to the closed position when flow in...

SEMPELL DEWRANCE CHECK VALVES BLED STEAM FLOW TESTS Extensive flow tests have been carried out to establish flow characteristics for these valves. The tests consisted of: 1. A scale model (230 mm) tested with air to establish the aerodynamic torque on the disc and the flow coefficient at various angles of opening. The lowest pressure drop occurs when the disc is in the fully open position. 2. A full size 400 mm valve tested in steam flows up to 300 ft/sec (92 meters/sec) to confirm the disc opening angle and establish the body and disc design shape. These tests confirmed that the Sempell...

SEMPELL DEWRANCE CHECK VALVES PRESSURE/TEMPERATURE RATINGS ASTM Body mat. cast WCB WCB WC6 WC6 WC9 WC9 ASME code B16.34 Std.* Spec.** Std.* Spec.** Std.* Spec.** ASTM Body mat. cast WCB WCB WC6 WC6 WC9 WC9 ASME code B16.34 Std.* Spec.** Std.* Spec.** Std.* Spec.** ASTM Body mat. cast WCB WCB WC6 WC6 WC9 WC9 ASME code B16.34 Std. * Spec. ** Std. * Spec. ** Std. * Spec. ** METRIC 400 INT CLASS (ASME B16.34) Prod. no. B43 B43 B43 B43 B43 B43 ♦ Std.* Spec.** ASTM Body mat. cast WCB WCB WC6 WC6 WC9 WC9 ASME code B16.34 Std. * Spec. ** Std. * Spec. ** Std. * Spec. **

SEMPELL DEWRANCE CHECK VALVES PRESSURE/TEMPERATURE RATINGS IMPERIAL 600 CLASS (ASME B16.34) Prod. no. ASTM Body mat. cast Pressure in lbf/sq. in. at temp. °F (for intermediate ratings use linear interpolation) 400 500 600 650 700 750 800 850♦ 900 950 1000 1050 METRIC 600 CLASS (ASME B16.34) Prod. no. B51 B51 B51 B51 B51 B51 ♦ Std.* Spec.** ASTM Body mat. cast WCB WCB WC6 WC6 WC9 WC9 ASME code B16.34 Std. * Spec. ** Std. * Spec. ** Std. * Spec. ** WCB material permissible but not recommended for prolonged usage above 800°F (425°C).

SEMPELL DEWRANCE CHECK VALVES BLED STEAM SIZES NPS 8 - 32 (DN 200 - 800) ASME B16.34 150 CLASS MAIN COMPONENT MATERIALS Description Body Cover Gasket Carbon steel A216 Gr. WCB A216 Gr. WCB Aluminium reinforced expanded graphite A216 Gr. WCB ASTM A565 XM32 Alloy steel A217 Gr. WC9 A217 Gr. WC9 Aluminium reinforced expanded graphite A217 Gr. WC9 ASTM A565 XM32 HYDROSTATIC SHELL AND SEAT LEAK TEST PRESSURES ASTM A-216 WCB Shell psi (bar) Seat psi (bar) ASTM A-217 WC9 Shell psi (bar) Seat psi (bar) Product numbers Alloy steel WC6 Product numbers Alloy steel WC6 DIMENSIONS (metric) NOTE Sizes...

SEMPELL DEWRANCE CHECK VALVES BLED STEAM SIZES NPS 6 - 32 (DN 150 - 800) ASME B16.34 400 INT CLASS MAIN COMPONENT MATERIALS Description Body Cover Gasket Carbon steel A216 Gr. WCB A216 Gr. WCB Aluminium reinforced expanded graphite A216 Gr. WCB ASTM A565 XM32 Alloy steel A217 Gr. WC9 A217 Gr. WC9 Aluminium reinforced expanded graphite A217 Gr. WC9 ASTM A565 XM32 HYDROSTATIC SHELL AND SEAT LEAK TEST PRESSURES ASTM A-216 WCB Shell psi (bar) Seat psi (bar) ASTM A-217 WC9 Shell psi (bar) Seat psi (bar) Product numbers Alloy steel WC6 Product numbers Alloy steel WC6 DIMENSIONS (metric) NOTE...

Alloy steel A217 Gr. WC9 A217 Gr. WC9 Aluminium reinforced expanded graphite A217 Gr. WC9 ASTM A565 XM32 MAIN COMPONENT MATERIALS Description Carbon steel Gasket Aluminium reinforced expanded graphite Disc A216 Gr. WCB HYDROSTATIC SHELL AND SEAT LEAK TEST PRESSURES NOTE Sizes greater than NPS 14 (DN 350) are available on application

SEMPELL DEWRANCE CHECK VALVES DESIGN SIMPLE DESIGN FOR MAXIMUM RELIABILITY IN OPERATION The disc is free to rotate on the hinge pin and the hinge pin is free to rotate on its bearings, thus ensuring freedom of movement and maximum reliability without the use of glands. Nitride treated hinge pin and bearings give hard wearing surfaces with a low coefficient of friction. Deposits on sealing surfaces are of different hardness and analysis to prevent ‘scuffing’. In the full open position the valves offer a maximum flow area as will be seen from the illustrations. Standard designs close in less...

SEMPELL DEWRANCE CHECK VALVES OPTIONS POWER ASSISTED CLOSING Where power assistance is required an air to open and spring to close pneumatic cylinder can easily be accommodated whilst still maintaining the automatic gravity closing feature. Power assisted valves can close in less than half a second but is dependent on size and pressure. TYPICAL SCHEMATIC AND WIRING DIAGRAM This is a basic diagram, however, other arrangements can be supplied to suit specific requirements. TYPICAL WIRING DIAGRAM Supply Turbine trip Solenoid High water level Test P.B. Closed limit switch Closed indicator lamp...