A Long Experience in Energy Equipment and one Goal: T h e C u s t o m e r ’s s a t i s fa c t i o n . ENERGY NEE VALVITALIA reserves the right to change design, specification and materials without notice 2 specification and materials without notice .DS CONTROL CONTENTS Globe Control Valves LTG1 LTG2 LTG3 LTG4 LTG5 RV631 4 4 6 8 9 18 Tree-way Control Valves TRV1 TRV2 10 10 Rotary Control Valves DYNA-LOK K-LO CB-54 CB-55 12 14 16 16 Steam Conditioning Control Valves PRDV SAN nozzles 20 22 3 VALVITALIA reserves the right to change design. 6” Ratings: up to ANSI 600 /PN100 Flanged. butt-welded. single seat LTG1 and LTG2 series are very versatile control valves of general use for any applications under moderate p/T service conditions. dirty. 1”. NEE Main advantages: ● ● ● ● Excellent plug stability provided by heavy top guiding design Interchangeable low noise and anticavitation trim either for std or quick-change design Tight shut-off class V and VI also available Wide flow range capability is allowed by a great number of reduced capacity trims LTG2 ANSI 300 Diaphgram Actuator Technical characteristics: Body: ● ● ● ● ● ● ● ● Sizes: 3/4”. 2”. Cr-Mo and Stainless Steels Bolted to body Extended for high and low temperatures Bellows seal Special design for cryogenic applications Same materials as body Top guided plug both in LTG1 and LTG2 constructions Linear. Cr-Mo and AISI 316 stainless steel Flow direction: – to open. modified linear and Eq% flow characteristics Plug types: – contoured – flat disc for quick opening operation – skirted and drilled BRD design (linear characteristic) for special services – soft seat . sticking and slightly abrasive fluids.only for contoured and flat disc Adjustable by nuts and follower Seal rings: reinforced braided teflon or pure graphite split-rings Bellows seal Cvmax / Cvmin better than 50:1 for 1" port and over Seat ring clamped into the body by the cage for quick-change feature Large windows of cage do not affect the inherent flow characteristic (including max Cv) of LTG1 corresponding trims Bonnet: ● ● ● ● ● Trim: ● ● ● Packing: ● ● ● Rangeability: Cage (LTG2 only): ● ● ● VALVITALIA reserves the right to change design. specification and materials without notice 4 .ENERGY LTG1 and LTG2 Control Valves Globe straight-way. such asr corrosive. 3”. Due to their simple construction and to their large range of available materials these valves are suitable for a wide range of applications. 1”1/2. SW. Angle-body LTA special design is also available with the same trims of LTG series. LTG1 is the standard design with screwed seat ring while LTG2 is the corresponding quick-change version with the same flow coefficients and pressure differentials capability. – to close for some flashing applications Materials: Carbon. also wrought or by bar for smaller dimensions Face-to-face dimensions as per IEC 60534 –3-1 materials: carbon. 4”. and threaded Cast construction. Increased Cv values in comparison with LTG1 and LTG2 standard body style due to less pressure drop of angle path 5 . material and actuators are the same of standard LTG series LTG1 ANSI 600 Electric Actuator LTA Control Valve Standard contoured plug BRD trim Soft seated plug LTG1 Std contoured plug LTG2 Std contoured plug 5 VALVITALIA reserves the right to change design.Centre-to-face dimensions consistent with IEC standard when the connections have the same dimensions 4 .Inlet and outlet ratings can also be different 3 .Trims. characteristics. In this case they are designated as LTA1 and LTA2 Control Valves. The advantages provided by LTA series are the following: 1 .DS Seat Ring: Leakage Class (IEC 60534-4) : Actuators: CONTROL ● ● ● ● ● Threaded in LTG1 model and clamped-in in LTG2 model Standard: class IV Optional: class V and VI Pneumatic diaphragm or Piston type Electric and Electro-Hydraulic actuators LTA design Globe types LTG1 and LTG2 are also available with angle body. specification and materials without notice .Different dimensions for valve inlet and outlet are available 2 . LTA series are special engineered designs. for piloted plugs and some flashing services Materials: Carbon. 4".long series materials: carbon. LTA series are special engineered designs. 2500 and equivalent PN Flanged. butt-welded.general feature – to close . 7 stages and over are obtained from a solid disk stack Linear and equal% characteristics for standard trim design Bonnet: ● ● ● Trim: ● ● ● ● Cage: ● ● ● ● LTG3 balanced plug VALVITALIA reserves the right to change design. wrought or bar for 2" and 3" sizes Face-to-face dimensions as per IEC 60534-3-2 . Cr-Mo and Stainless Steels Standard or extended type either for high or low temperature applications Bolted to body Same materials as body Balanced and fully cage-guided plug Unbalanced design for small ports or low pressure drop applications Piloted design for tight shut-off associated to high fluid temperature Plug seal rings: PTFE. metal or metal and graphite Low-noise drilled cage single stage LN and special ELN type with additional acoustical benefit of 4 dB. 600. 20" Ratings: up to ANSI 150. 18". LTG3 is particularly suitable for heavy duties and for any other application under most demanding service conditions. severe low-noise requirements and sour service in accordance with NACE standard. including also high temperature and corrosive fluids. socket-welded and threaded Cast standard construction. The advantages provided by LTA design are the same of LTA1 series. to the large range of trim types and available materials. specification and materials without notice 6 . 12". 900. Cr-Mo and AISI 316 stainless steel Flow direction: – to open . Technical characteristics: Body: ● ● ● ● ● ● ● ● Sizes: 2". 10". NEE Main advantages: ● ● ● ● ● ● ● ● High pressure drop capability with no practical limitations Improved plug stability due to large guiding areas Wide-range capability is allowed by a great number of reduced capacity trims Excellent noise attenuation with low-noise single-stage trim for gas and steam service Improved cavitation protection on liquid services Multistage trims also available for cavitation control. 3". 1500. these valves are suitable for a wide range of applications. 8". In this case they are designated as LTA3 Control Valves. MPS multistage trim special design for high pressure drops Multi-cage construction up to 6 stages. Balanced plug construction reduces thrust and actuator sizes Piloted plug construction for tight shut-off up to class V in high temperature services LTG3 20” ANSI 900 LTA design LTG3 are also available with angle body.ENERGY LTG3 Cage Control Valves Globe straight-way LTG3 series is a very versatile control valve for the main applications. 16". Its high performance derives by using a balanced and cage-guided plug. 6". 14". 300. Due to their simple construction. IV S1 and V according to IEC 60534-4 Class VI is also available with soft-seat Pneumatic diaphragm or Piston type Electric and Electro-Hydraulic actuators Single stage Low noise cage ● ● ● MPS trim balanced plug LTG3 plug with soft insert Linear characterized LTG3 cages MPS multistage trim Double stage balanced plug Low noise cage construction LTG3 .DS Seat Ring: Leakage Class: Actuators: CONTROL ● Quick-change and free-expanding type. IV. specification and materials without notice 7 .cage assembling LTG3 .control valve under cryogenic test VALVITALIA reserves the right to change design. precisely coupled to the cage to ensure a perfect plug alignment Classes III. Cr-Mo and Stainless Steels materials: carbon. 2500 Materials: Carbon. VALVITALIA reserves the right to change design. The main difference is the design of the plug which is balanced type and contoured shaped for the throttling function. IV. 900. Two separate sealing surfaces can be provided: by this way the first seal. between seat and cage. metal and graphite Linear and equi% up to 2” port included . also wrought or bar construction for 2" and 3" sizes Face-to-face dimensions as per IEC 60534-3-1 long series Sizes: 2". IV S1 and V according to IEC 60534-4 Class VI is also available with soft-seat plug Piston or pneumatic diaphragm spring return Electric actuators on request Bonnet: ● ● ● Trim: ● ● ● ● Seat Ring: Leakage Class: Actuators: ● ● ● ● Cascade trim Represents one of the most valid systems to reduce erosion and cavitation and it finds wide applications in small size valves. 6".cascade trim 8 .modified linear for higher sizes Plug types: – contoured – flat disc for quick opening operation – soft seat – soft seat – cascade trim Quick-change and free-expanding type. Also dirty. The pressure drop is equally splitted through a lot of labyrinth paths specially machined inside the trim itself. abrasive and very corrosive fluids can be successfully handled without the inconvenient sometime occurring in conventional throttling cage valves. Control valves equipped with “cascade trim” can operate under very high pressure drops with a longer working life compared to standard single stage trims. 300. 1500. teflon. 8". clamps the seat ring against the body and acts also as the integral guide of the plug. 600. 10". Cr-Mo and AISI 316 stainless steel Flow direction: to open Bolted joint to body Extended type either for high and low temperature applications as a standard feature Same materials as body Balanced and fully guided plug Seal rings for leakage classes IV and better: metal. 12". butt-welded Cast std construction. precisely coupled with the cage to ensure a perfect plug alignment Classes III. coatings and flow characteristics. 3". The trim is of quick change type for an easy maintenance. The cage. provided with large windows. 4". ratings up to ANSI 150. acts as a sacrifice element. The limitations about low-noise and anticavitation characteristics are compensated by the free-passage shape of the plug with reduced risk of local erosionand clogging. specification and materials without notice LTG4 . These valves combine the benefits of plug balancing and quick-change feature of LTG3 series with the simple and versatile construction of contoured plug which allows a wide selection of materials. whether other “multistep” solutions can not be used. NEE Technical characteristics: Body: ● ● ● ● ● ● ● LTG4 10” ANSI 2500 Flanged.ENERGY LTG4 Series Control Valves Globe straight-way LTG4 Series Control Valves have the same body. bonnet and seat ring of LTG3 series. Cr-Mo. Particular care is paid to the packing zone where stagnation of fluid could cause stem corrosion. HVD1. 3”. hastelloy. but a different plug-to-stem solid construction is performed in LTG5 valve to avoid any residual areas where fluids can stagnate. AISI 316L. duplex. melamine and similar plants Main features: 1 . Typical applications of these valves are: ● ● ● Food industry and drinking water Pharmaceutical processes Urea.DS CONTROL LTG5 Series Control Valves LTG5 Series top guided control valves are specially designed for the control of particular fluids where dead zones inside the valve body are not tolerated due to risk of crystallization. 6” Ratings up to ANSI 600 – ANSI 1500 for sizes up to 2” included Materials: carbon. These features pertain to top guided LTG1 series.Stem-to-plug solid design which: – avoids dead zones inside the bonnet including packing box chamber – avoids coupling stem–to–plug which can be affected by local corrosion and consequent loosening – provides an excellent alignment between stem and plug with benefit for the packing tightness – increases trim stiffness due to oversized stem diameters 3 . specification and materials without notice . local corrosion. Cv and other sizing factors are the same of LTG1 series. scaling or seizure. 1”1/2.reduced distance from packing to body inside cavity keeps the packing temperature very close to that of internal fluid so to prevent solidification inside the packing LTG5 high pressure lug body type for urea service Technical characteristics: Body: ● ● ● ● ● ● ● Flanged and butt-welded connections –also plug type is available Cast construction – also wrought or by bar for small dimensions Face-to-face dimensions as per IEC 60534-3-1 long series Sizes: 3/4”. duplex. other alloys and coatings on request and when necessary Std IV – optional V or VI Pneumatic diaphragm or piston types Electric and electro-hydraulic on request Bonnet: ● ● ● ● ● ● ● ● ● Trim: Materials: Leakage Class: Actuators: ● ● ● ● 9 VALVITALIA reserves the right to change design. 2”. 4”.No dead zones inside the body with reduced contamination and erosion 2 . hastelloy for sizes up to 3” – other on request Flow direction: – to open – to close only for balanced plug Flanged to body Same materials as body seal rings: reinforced braided Teflon or pure graphite Top guided unbalanced plug – integral with stem Guide: an extra-long bush fitted into the bonnet Flow characteristic: linear and equi% up to 2” port included modified linear for higher sizes Type of plug: contoured or flat for quick opening operation Soft seat: teflon insert fitted into the plug seat ring: threaded in std design – also welded-in or integral for high corrosive services Inox. 1”. AISI 316. wear and leaks. TRV1 diverting type is generally preferred for high T(120° and over) but when T1 exceeds 350°C (up to 450°C) mixing type TRV2 is preferred. 300. etc.1 – DIVERTING TYPE 3-way control valve in heat exchanger application Fig. Cr-Mo and stainless steels Plain or extended type either for high or low temperature applications as a standard feature Bolted to body Same materials as body Intrinsically balanced in heat exhanger application Plug is available in two design: standard and low-noise TRV2 Control Valve 12” ANSI 600 (mixing type) Bonnet: ● ● ● Trim: ● ● VALVITALIA reserves the right to change design. Generally. In the layout of Fig. headers. wrought or bar construction also available for small sizes Flow direction: see sketckes Materials: carbon.2 – Mixing type 3-way control valve in heat exchanger application TRV Design In both designs the fluid tends to open the plug to ensure the max stability to the valve operation.ENERGY TRV1 and TRV2 3-way Control Valves NEE TRV control valves series are especially designed for heat exchangers control where the flow rate of the heating fluid which enters the heat exchanger is changed by the temperature controller.1 and 2 both the two methods used for this process switch-off the flow rate into a by-pass line around the exchanger. 600 900 and 1500 on request Flanged connections Cast standard construction. As outlined in the sketches of Fig. specification and materials without notice 10 .). The selection between the two solutions is basedprincipally on fluid temperature and on the differential temperature T1-T2 across the exchanger. mixing type is preferred as it is less expensive and due to easier maintenance. Technical characteristics: Body: ● ● ● ● ● ● Sizes: from 1" up to 12" Ratings: up to ANSI 150.1 the valve is the diverting type TRV1 with one inlet and two outlets while in the arrangement of Fig 2 the valve is the mixing type TRV2 with two inlets from heat exchanger and by-pass. Fig. The use of the by-pass around the exchanger limits the changes of pressure in the main line with many benefits for the assisted final equipment (boilers. specification and materials without notice .DS CONTROL 11 VALVITALIA reserves the right to change design. specification and materials without notice 12 . the torque tending to close the valve and. Over-sized bearings (total length = 3. the cam effect performed by second shaft eccentricity guarantees a seal ring longer life. PN16 for greater sizes For water mains DYNA-LOK control valves can be supplied in accordance with AWWA std ratings and connections Cast or fabricated construction depending on body style. 50° opening. PN 40 up to DN 600 included. For higher dimensions IVS1 class or better depending on actuator For metal SS type IVS1 class is allowed for all sizes Valvitalia DRA pneumatic diaphragm actuator for valve sizes up to 16” Valvitalia PRA piston types actuators with low friction scotch-yoke mechanism for larger valve sizes Pneumatic rack and pinion both single and double acting for sizes up 24” included Electric. XM19 Radial bearings: Teflon-based compounds embedded in SS bushing. ISO 5752 Materials: all carbon and stainless steel grades. ANSI 150. electro-hydraulic and hydraulic actuators for heavy duties control purpose Leakage Class: ● ● Actuators: ● ● ● ● VALVITALIA reserves the right to change design. 17-4-PH. linear from 45° to max travel Materials: same as the body Constructions: one or two pieces depending on sizes Connection to the disc: by pins protected by set screws External sealing: single stuffing box actuator side Packing materials: teflon or graphite seal rings Materials: stainless steels. In addition. Teflon seal ring assembly is consistent with class V (IEC 60534-4) for sizes up to 20”. duplex and copper alloys Double eccentric design when tightness in closed position is requested Full-bore swing-through construction with single off-set disc when no tightness is requested in closed position Solid or whrougt cast construction Bi-directional flow but inlet on flat disc side gives better performance Flow characteristic: increasing gain up to approx. These valves can offer a great flow control with an excellent shut-off withstanding also very high pressure drops. IEC 60534-3-1.ENERGY DYNA-LOK rotary Control Valves DYNA-LOK rotary control valves are provided with a double eccentric disc and a very easy-to-be changed TFE based or metal seat ring. NEE Technical characteristics: Body: ● ● ● ● ● wafer and lug body design: from DN 150 up to DN 2000 flanged body: from DN 250 up to DN 2000 Ratings: up to ANSI 300.5 x ) allow a smooth rotation and a long maintenance-free valve life Axial bearings: axial thrusts are held by a couple of anti-friction washers Sizes: Disc: ● ● ● ● ● ● Shaft: ● ● ● ● ● Bearings: ● ● High pressure DYNA-LOK control valve with PRA actuator Seat Ring: ● Two designs are available to fulfil different temperature conditions: – spring-energized Teflon ring for temperatures up to 200°C – SS ring for higher temperatures Both seal rings are locked inside the body by means of an easily removable spacer. Thanks to DYNA-LOK disc off-set design. more in general the torque needed to control the disc rotation is sensitively reduced. independently of the flow direction. size and material selection Face-to-face dimensions as per EN 558. specification and materials without notice .DS CONTROL The requested torque to move the disc of a DYNA-LOK valve is mainly depending on the differential pressure across the disc and on the values of pressures inside the body. while. in opened position.lug body construction 13 VALVITALIA reserves the right to change design. DYNA-LOK disc design limits very much this second well-known effect especially in the usual working travel range from 40° to 90°. 32” DYNA-LOK control valve . it creates a dynamic force due to a not balanced distribution of pressures acting on the disc. The p increases friction of seal ring and shaft bearings in closed position. up to DN 600 included. For higher dimensions IVS1 class or better depending on actuator For metal SS type IVS1 class is allowed for all sizes Valvitalia DRA pneumatic diaphragm actuator for valve sizes up to 16” Valvitalia PRA piston types actuators with low friction scotch-yoke mechanism for higher valve sizes Pneumatic rack and pinion both single and double acting for sizes up 24” included Electric and hydraulic actuators available on request Disc: ● ● ● ● ● ● ● ● Shaft: ● ● ● ● ● Bearings: ● ● Seat Ring: ● Leakage Class: Actuators: ● ● ● ● ● ● VALVITALIA reserves the right to change design. NEE Technical characteristics: Body: ● ● ● ● ● Sizes: from DN 250 up to DN 2000 Ratings: up to ANSI 300. ANSI 150. Best leakage performance is assured by flow on flat disc side Opening up to 100° High xFZ cavitation index values Flow characteristic: increasing gain up to approx. PN16 for greater sizes. The oversizing of these bearings (tot. basic series 13 Materials: all carbon and stainless steel grades. 17-4-PH. Flanged design (cast or fabricated construction depending on the size and material selection) Face-to-face dimensions as per EN558.ENERGY K-LO high-performance Rotary Control Valves K-LO rotary control valves have been especially designed to meet the usual cavitation problems of processes when hot liquids and not negligible pressure drops facilitate the development of cavitation. The distribution of the windows takes into account the presence of the sealing ring fitted into the body. with particular care to the area close to the shaft axis. specification and materials without notice 14 . PN 40. duplex and copper alloys Double eccentric design when tightness in closed position is requested Two disc designs are available: drilled wings for low noise services and multi-windows wings for anticavitating service Full-bore swing-through contruction with single off-set disc when no sealing device is requested in closed position Both sides flow directions. the off-set design reduces the torque tending to close the valve. which increase the recovery factor of valve as well as its cavitation index grows. As for DYNA-LOK valves. linear from 50° to max travel Materials: same as the body Constructions: one and two pieces depending on sizes Connection to the disc: by pins protected by screws External sealing: single stuffing box actuator side Packing materials: teflon or graphite seal rings Materials: stainless steels. integral or welded-in on both the disc sides. XM19 Radial bearings: Teflon-based compounds embedded in SS bushing. the cam effect caused by second shaft eccentricity improves the seal ring life. max valve openings greater than the usual 90° are allowed to achieve higher Cv values. ISO 5752. length = 3.5 x ) allows a smooth rotation and a long maintenance-free valve life allow a smooth rotation and a long maintenance-free valve life Axial bearings: axial thrusts are held by a couple of anti-friction washers Two designs are available to fulfil different temperature conditions: – spring-energized Teflon ring for temperatures up to 200°C – SS ring for higher temperatures Both seal rings are locked inside the body by means of an easily removable spacer Teflon seal ring assembly is consistent with class V (IEC 60534-4) for sizes up to 20”. Due to particular disc baffled design. 50° opening. In addition. These baffles are wing-shaped and machined with many rectangular windows providing a moderate pressure drop so to not greatly affect the Cv of the valve with the plain disc. These special valves are deriving from the double eccentric DYNA-LOK series by modifying the basic disc design with particular baffles. 5 bar (water at 125°C). which are close to 0. This allows to avoid cavitation under critical conditions. Low-noise disc design Anti-cavitation disc design 15 VALVITALIA reserves the right to change design. while allowed disc opening is limited to the region where recovery factor is higher. p2 = 10 bar and max vapour pressure = 2. such as. depending on wings size.DS CONTROL Multi windows wings These special trim executions are machined. This peculiar trim pattern combines high efficiency in reducing noise with an excellent modulating performance. specification and materials without notice . from a solid cast or forged block. Cavitation and noise control Drilled wings Special drilled wings allow K-LO control valve to reduce noise. for example: p1 = 15 bar. Flow coefficients are slightly affected by the anti-cavitation large windows of the wings. The design of K-LO disc is very effective against potential cavitating conditions due to its high xFZ values.4 at 70° opening approximately for all the dimensions. CB 55 special multi-path / multi-stage trim allows an excellent flow control. In this way it is possible to reach reangeability of 200:1 and with particular trims until 300:1. A479 XM19 Packing: teflon or graphite ring Radial bearings: generous sizing of these bearings allows a smooth rotation and a maintenance-free long life Axial bearings: thrust due to internal pressure is held from an antifriction washer Spring energized. nickel alloys CB 55 series with integral trim up to 4” With removable trim for 6” and over Soft / metal to metal seat Flow direction: – unidirectional: CB 54 – bidirectional: CB 55 Materials: same as body Anti blow-out design Quick changing shaft packing Materials: stainless steel. specification and materials without notice 16 . hydraulic. CB series valves match together the ability to transfer large flows with a precise regulating action at small flows. electro-hydraulic CB54 gas plant installation Ball: ● ● ● ● ● CB54 drilled disc view Shaft: ● ● ● ● Bearings: ● ● Seat: ● ● Actuators: ● ● ● Leakage Class: ● Classes IV. double-effect piston construction on request Soft / metal to metal seat Pneumatic low friction skotch-yoke PRA type DRA pneumatic diaphragm type Electric. Furthermore the special trim design of CB series provides noise and cavitation abatement. IV S1 and V according to IEC 60534-4. Class VI is also available with soft-seat VALVITALIA reserves the right to change design. duplex. CB series are available in two configurations: NEE 1. typical of on-off ball valves with a high rangeability. A564 T630. Technical characteristics: Body: ● ● ● ● ● Side entry flanged and butt-welded design Size: from 2” to 42” Rating: from #150 to #2500 Face to face dimensions API 6D Materials: carbon and stainless steel. CB 54 has a downstream drilled disc especially engineered to reduce aerodynamic noise 2. and it is especially designed to reduce both noise and cavitation effects.ENERGY CB54 – CB55 Ball Control Valves Control Ball Valves of CB series provide an excellent tightness. DS CONTROL CB54 CB55 sectional view CB55 VALVITALIA reserves the right to change design. specification and materials without notice 17 . 300. Cr-Mo and stainless steels Bolted to body Same material as body Flow direction: to open Packing materials: teflon or graphite seal rings Materials: Carbon. Different arrangements of stages distribution can be performed to fulfil special applications Quick-change and free-expanding type. in which high pressure drops might generate cavitation phenomena. splitted in 3 steps along the travel. During the first travel section. allows the RV631 trim to meet these process requests. 4”. They are expressly designed for processes that require low pressure drops when the flow rate is high and the need to avoid cavitation when flow rate is small. NEE Technical characteristics: RV631 Control Valve Body: ● ● ● ● ● ● ● ● ● ● ● ● Sizes: 3”. is separated by lips that prevent the fluid passage between adiacent sections. IV S1 and V according to IEC 60534-4 Bonnet: Trim: ● ● ● ● Cage: ● ● Seat ring: ● Leakage Class: Actuators: ● ● ● Pneumatic diaphragm or piston type Electric and electro-hydraulic actuators 6-stage multistep cage detail VALVITALIA reserves the right to change design. The last section has a final single stage cage with large flow passages which ensures the maximum flow rate with moderate pressure drop. 12” Ratings: ANSI 150. 8”. 600. specification and materials without notice 18 . SW Cast standard construction Face-to-face dimensions as per IEC 60534-3-2 Flow direction: to open Materials: Carbon. 1500 Flanged. 10”. Each section of the cage. BW. Cr-Mo and stainless steels Balanced and fully cage-guided plug Unbalanced design for small ports or moderate pressure drop applications Plug seal rings: PTFE. precisely coupled with the cage to ensure a perfect plug alignment Classes IV.ENERGY RV631 series Control Valves RV631 control valves have their main application in boiler feedwater process. 6”. 900. The special design of its cage. welded together to form a solid rugged unit. the process is controlled by a properly designed multistep cage. which causes the fluid to pass through six pressure reduction stages: in this way any vaporization is avoided. metal or metal and graphite Flow characteristic: modified linear (see diagram) Variable resistance along the travel: 6-stages for low openings. 3-stages for intermediate travel and single-stage at full opening. specification and materials without notice .DS CONTROL Last cage section with single-stage and high specific CV Intermeditate section with 3-stage and increased specific CV 6-stage first anti-cavitation section RV631 3-step cage CV and XFZ vs travel 19 VALVITALIA reserves the right to change design. specification and materials without notice 20 . Conditioning includes pressure reduction and integrated desuperheating devices. The first stage is the throttling section where flow rate is adjusted by the change of plug position inside a drilled cage. Desuperheating section consists of a chamber installed downstream the third stage where some spring-assisted nozzles are mounted. The third stage has a patented cone-shaped special designed drilled ring wich contributes to noise reduction and improves the mixing of steam with the downstream injected water. F91 (9%Cr) depending on service conditions Plug: Seat Ring: ● Unbalanced or balanced with seal rings and pilot assisted depending on service conditions ● Welded-in by a double lip-seal joint which grants against thermal distortions and allows an easy removal from the body Unbalanced and pilot assisted plug: class V (as to IEC 60534-4) Balanced plug with seal ring: class IVS1 Leakage Class: Actuators: ● ● ● ● Double effect. electro-hydraulic and hydraulic actuators for heavy duties control application Trim: stellited or nitrided F6NM alloy steel and AISI 422 (1-4935) 17-4-PH is used for inlet temperature up to 375°C Stem: AISI 316 or XM19 depending on service conditions Packing: pure graphite seal rings Pressure seal ring: low hardness AISI 316 PRDV Control Valve section Materials: ● ● ● ● VALVITALIA reserves the right to change design. Outlet section up to ANSI 900 included Construction: from bar stock or forgings. Pressure reduction is obtained through three stages. The second stage is a fixed resistance performed by a drilled basket. which creates a backpressure on the seat in order to reduce its velocity head and the generated noise.ENERGY PRDV steam conditioning Control Valves PRDV control valve is a very efficient and compact equipment for steam conditioning either in turbine by-pass lines discharging to condenser or in cogeration processes (see included layout). Shape and orientation of this ring optimize the steam impact against the external surface of sprayed water pattern. NEE Technical characteristics: Body and Bonnet: ● ● ● ● ● PRDV Control Valve (patented design) Sizes: sizes depending on service conditions Ratings: inlet section up to ANSI 2500. including a jacketing of internal surface of injection chamber which is recommended for high pressure sytems and whenever steam inlet temperature exceeds 500°C. except in LP applications where two stages are adequate to provide good performance and noise limitation. where the biggest water drops tend to reunite and to improve the atomizing efficiency of the equipment as a whole. Great care is taken to avoid any risk of thermal shocks. Inlet connnection and injection chamber are welded to main body section Pressure seal design for inlet ratings over ANSI 900 Materials: carbon steel or Cr-Mo steels. spring-assisted Valvitalia LPA pneumatic piston actuators are commonly used Electric. specification and materials without notice 21 . the effective Cv value for predicting the flow rate is the same of first stage. Steam conditioning PRDV valves in a combined cycle process plant PRDV preheating layout – circulation type VALVITALIA reserves the right to change design. is not useful for selecting the valve. where flow rate does not depend on downstream pressure. unexpected errors on fixed resistances sizing do not affect the flow rate passing through the valve as long as limit conditions are held on first stage.DS CONTROL Sizing and noise prediction Standard well-known sizing equations (IEC 60534-2-1) are notapplicable to PRDV control valves as a whole due to the fixed area devices assembled downstream the throttling stage. In limit flow conditions. The total Cv of PRDV. The overall PRDV noise calculation is made by a proprietary VALVITALIA method based on the most advanced studies supported by on-line verifications. To predict noise generated by PRDV control valves the basic principles of IEC 605434-8-3 standard are taken into account. including all downstream devices (fixed resistances). The accuracy of the combination of calculated Cv is guaranteed by the Valvitalia’s deep knowledge and large experience on this matter. Both cone shaping of 3rd stage and the optimized steam/water mixing do contribute to the reduction of acoustic power transmitted downstream (IEC rw factor). all the stages are separately sized according to IEC equations and the selection of the whole valve is performed for each specific application. The sizing of 2nd and 3rd stage is based on the assumption that full pressure recovery occurs between the stages so to allow a complete fluid reheat after the restrictions. However. For this reason. the p between steam and water increases till the water action on the plug exceeds the spring load and the plug starts opening. SAN 5 nozzle VALVITALIA reserves the right to change design. The closed position of the plug (51) is assured by the action of a calibrated spring (53) loaded by a threaded nut (52) locked in position by a pin (54). The special plug profile on the external surface which is in contact with steam flow improves plug stability in open position. due to their special design. When the water pressure inside the nozzle rises. The plug perfectly atomizes the water performing a 90 degrees-shaped conical blade. The water starts to come out from the nozzle flowing through several holes that. specification and materials without notice SAN nozzle spray pattern 22 . 1. Injection chamber is normally manufactured with the same pipe material. whirl the flow before it gets in contact with the inside surface of the plug. Other set pressure values can be provided for special requirements.3 and 5 bar are our standard settings. INCONEL X-750 has been selected for springs to ensure maximum stability at highest temperatures.ENERGY SAN series desuperheating nozzles SAN NOZZLES are variable area spring-assisted nozzles for desuperheating service. NEE Materials: SAN body materials are carbon steel or Cr-Mo steel according to operating temperature. Spring load can be adjusted to obtain the desired opening pressure. DS CONTROL Spring settings for SAN nozzles SAN nozzle rear view SAN series SAN Desuperheater Mounting Side-pipe mounting Probe mounting One or more SAN desuperheater can be fastened at the end on a tubular element flanged or welded to the pipe. A reference pin located on the desuperheater flange ensures the correct orientation of the nozzle inside the piping. The spray is performed close to the pipeaxis by selecting the probe lenght. specification and materials without notice . 23 VALVITALIA reserves the right to change design. Fax: +39.Italy Phone: +39.A Long Experience in Energy Equipment and one Goal: T h e C u s t o m e r ’s s a t i s fa c t i o n .9125455 E-mail: info.9199611 . VALVITALIA S.Control Valves Division Via Campolongo.valvitalia.com 04.CVD.35020 Due Carrare (PD) . Padova Plant.1000 .049. 97 .p.10 .04 [email protected] Web site: www.A. .