8.CONTROL VALVES& ACTUATORS

8.00.00  CONTROL VALVES, ACTUATORS & ACCESSORIES

 

8.01.00  GENERAL REQUIREMENTS

 

      a) The control valves and  accessories equipment  furnished

 

         by the bidder shall be designed. constructed and  tested

 

         in accordance with the latest applicable requirements of

 

         code  for  pressure  piping  ANSI,  the  ASME  Boiler  &

 

         pressure vessel code, Indian Boiler Regulation(IBR), ISA

 

         and   other standards specified elsewhere as well as  in

 

         accordance  with  all  applicable  requirements  of  the

 

         “Federal Occupational Safety and Health standards,  USA”

 

         or acceptable equal standards.  All the Control  Valves,

 

         their  actuators and accessories to be  furnished  under 

 

         this section will be fully suitable and compatible  with

 

         the  modulating loops covered under SG C&I, TG  C&I  and

 

         closed loop control system of the specification.

 

      b) All  the  control vales and accessories offered  by  the

 

         bidder, shall be from reputed experienced  manufacturers

 

         of specified type and range of valves.

 

8.02.00  CONTROL VALVE SIZING & CONSTRUCTION

 

8.02.01  The   design  of  all  valve  bodies  shall   meet   the

 

         specification  requirements  and shall  conform  to  the 

 

         requirements  of  ANSI(USA)  for  dimensions,   material

 

         thickness   and   material   specification   for   their

 

         respective pressure classes.

 

8.02.02  The valve sizing shall be suitable for obtaining maximum

 

         flow conditions with valve opening at approximately  80%

 

         of  total valve stem travel and minimum flow  conditions

 

         with valve stem travel not less than 10% of total  valve

 

         stem  travel.   All  the  valves  shall  be  capable  of

 

         handling  at least  120% of the  required  maximum  flow.

 

         Further, the valve stem travel range  from minimum  flow

 

         condition to maximum flow shall not be  less than 50% of

 

         the  total valve stem travel.  The sizing  shall  be  in

 

         accordance  with  the  latest edition  of  ISA  standard

 

         “ANSI/  ISA-75.01.01,  Flow  Equations  for  sizing   of

 

         control  valves.”  While deciding the  size  of  valves,

 

         bidder shall ensure that valves outlet velocity does not

 

         exceed 8 m/sec for liquid services, 150 m/sec for  steam

 

         services   and  50%  of  sonic  velocity  for   flashing

 

         services.  Bidder shall furnish the sizing  calculations

 

         clearly indicating the outlet velocity achieved with the

 

         valve   size   selected  by  him  as   well   as   noise

 

         calculations   as  per  ISA-75-17-1989  “Control   valve

 

         Aerodynamic Noise Prediction”  which will be subject  to

 

         Owner’s approval during detailed engineering.

 

8.02.03 (a)Control valves for steam and water applications shall be 

 

         designed  to prevent cavitations, wire drawing,  flashing

 

         on the  downstream side of valve and down stream side of

 

         valve  and  down stream piping.   Thus  for  cavitations/

 

         flashing  service, only valve with anti cavitations  trim

 

         shall be provided. Detailed calculations as per  ISA-RP-

 

         75-23-1995  “Consideration for evaluating control  valve

 

         cavitations” to establish whether cavitations and erosion

 

         will  occur  or not for any given application  shall  be

 

         furnished.

 

(a)     The liquid pressure recovery factor (FL) shall be 0.995 or better for severe flashing/cavitation services.

(b)     The liquid pressure recovery factor (FL) shall be 0.985 or better for low flashing/cavitation services.

 

 8.02.04 Leakage Class

 

         Control  valves  for application such  as  HP/LP  Heater

 

         emergency level control, SH spray &  RH spray control,

 

         Emergency makeup to Hotwell, deaerator drain to condenser

 

         hotwell, & heavy oil heating,  HFO & LDO and pressuring and 

 

         control system, condenser  normal make-up and valve shall        

 

         have permissible leakage rate as per leakage Class – V

 

        (ANSI/ FCI). All other control valves such  as low and high 

 

         range feed control valves, LP/HP heaters normal/ level

 

         control valves etc. shall have leakage rate as per leakage

 

         Class-IV. All SH/RH Block valves, shut-off valve of LDO &

 

         HFO and BFP recirculation valve shall have leakage class

   

         MSS-SP-61.

 

8.02.05  The control valve induced noise shall be  limited to  85

 

         db  A  at  1 Mtr. from the valve  surface  under  actual

 

         operating  conditions.   The noise  abatement  shall  be

 

         achieved by valve body and trim design and not by use of

 

         silencers.

 

8.02.06  The  characteristic  of  the  control  valves  shall  be 

 

         determined based on the  application/ service.

 

8.02.07  Valve Construction

 

      i) All valves shall be of globe body design &  straightaway

 

         pattern with  single or double port.  Unless other  wise

 

         specified  or recommended by the manufacturer to  be  of

 

         angle  body  type.  Rotary valve  may  alternatively  be

 

         offered when pressure and pressure drops permit.

 

     ii) Valves  with high lift cage guided plugs & quick  change

 

         trims shall be supplied.

 

    iii) Cast iron valves &  asbestos packing are not acceptable.

 

     iv) Bonnet  joints for all control valves shall be   of  the 

 

         flanged   and   bolted  type  or    other   construction

 

         acceptable to the MPSEB.  Bonnet joints of the  internal

 

         threaded or union type will not be acceptable.

 

      v) Plug  shall be of  one-piece  construction either  cast,

 

         forged or machined from solid bar stock.  Plug shall  be

 

         screwed and pinned to valve stems or shall be   integral

 

         with the valve stems.

 

     vi) All valves connected to vacuum on down stream side shall

 

         be    provided   with  packing   suitable   for   vacuum

 

applications(e.g. double vee type chevron packing). For

 

other valves packing material shall be Grafoil/double.

 

    vii) Valve  characteristic  shall  match  with  the   process

 

         characteristics.

 

   viii) Extension  bonnets shall be provided when  the   maximum

 

         temperature of flowing fluid is greater than 280 Deg.C.

 

     ix) Flanged valves shall be rated at no less than ANSI press

 

         class of 300 lbs.

 

     x)  If  the  down  stream  is  subjected  to  vacuum,   flow

 

         direction of fluid shall be to close.

 

    xi)  The control valve for low load feed control valve, SH  &

 

         RH Attemp.Temp.Control Valve, Recirculation valve of BFP

 

         shall be multipath, multistage, velocity head loss type. 

 

8.03.00  VALVE MATERIALS

 

         The  control  valve  body/trim material  shall  be –

 

    (i)  Non  corrosive, non flushing and non cavitation  service

 

         below 280 Deg.C like Aux.steam flow to deaerator,  cond.

 

         flow to deaerator, CRH flow to deaerator.

 

      a) Body Material  - The body material shall be carbon steel

 

         ASTM-A  216  Gr.WC B except CRH flow  to  deaerator  and

 

         alloy steel ASTM A 217 Gr.WC 9 for CRH flow to deaerator.

 

      b) Trim  Material  -  The trim material  shall  be  316  SS

 

         stellite faced guide and bushings.

 

    (ii) Severe  flashing/cavitation services like  feed  control

 

         valve,  spray  control  valve (SH  &  RH  Spray control 

 

         and block valve) L P heater & H P heaters.  Emergency level

 

         control valve,  HPBP Spray control valve, deaerator over

 

         drain etc.

 

      a) Body Material shall be  ASTM A 217 WC 9.

 

a)    Trim  material  shall be  17-4 PH SS

 

   (iii) Low  flashing/  cavitations service like HP heater/ LP

 

         heater normal level control, Condensate/feed water below

 

         280 Deg.C etc.

        

      a) Body Material shall be Alloy Steel as per ASTM A 217 WC6.

 

      b) Trim  material shall be 17-4 PH SS          

 

    (iv) Normal  & Emergency make up D M  water control 

        

      a) Body Material shall be  A 351 Gr CF 8M

 

      b) Trim Material shall be  316 SS +ST

 

     (v) Fuel oil and atomising steam service

 

      a) Body Material shall be Alloy Steel ASTM A 216 WCB.

 

      b) Trim  material shall be 316 SS stellite.

 

         However,  bidder  may offer valves with  body  and  trim

 

         materials  better than specified materials and in  such,

 

         cases bidder shall furnish the comparison of  properties

 

         including   cavitation  resistance,  hardness,   tensile

 

         strength,   strain  energy,  corrosion  resistance   and 

 

         erosion  resistance etc. of the offered material  vis-a-

 

         vis the specified material for MPPGCL’s consideration and

 

         approval. 

 

8.04.00  END PREPARATION

 

         Valve   body  ends shall be either butt  welded/  socket

 

         welded, flanged or screwed as finalised during  detailed

 

         engineering  and  as per MPPGCL approval.   The  welded

 

         ends wherever required shall be  butt welded type as per 

 

         ANSI  B  16.25  for control valves of sizes  65  mm  and

 

         above.   For  valves sizes 50 mm and below  welded  ends

 

         shall be socket  welded  as per  ANSI B 16.11.   Flanged

 

         ends  wherever  required  shall  be  of  ANSI   pressure

 

         temperature  class equal to or greater than that of  the 

 

         control valve body.

 

8.05.00  VALVE ACTUATORS

 

      (a)All  control  valves shall be furnished  with  pneumatic

 

         actuators.  The Bidder shall be responsible for   proper

 

         selection  and sizing of valve actuators  in  accordance

 

         with the pressure drop and maximum shut off pressure and

 

         leakage  class requirements.  The valve actuators  shall

 

         be capable of operating at 60 Deg.C. continuously. Valve

 

         actuators  and stems shall  be  adequate to handle  the

 

         unbalanced  forces occurring under  the  specified flow

 

         conditions  or   the   maximum  differential  pressure 

 

         specified.   An  adequate  allowance  for  stem   force,

 

         atleast  0.15 Kg/Sq.Cm.per linear millimeter of  seating

 

         surface,  shall  be provided in the   selection  of  the 

 

         actuator   to  ensure  tight  seating  unless  otherwise

 

         specified.  The travel time of the actuators  shall  not

 

         exceed 10 secs.

 

    (b) All valve control valve shall be provided with smart digital valve positioners and connect with hart management system. 

 

8.06.00  CONTROL VALVE ACCESSORY DEVICES

 

         All  control  valve  accessories  such  as  air   locks,

 

         handwheels/hand-jacks,   torque/ Position limit  switches

 

         positioners,

 

         solenoid  valves, diffusers, external  volume  chambers,

 

         position  transmitters(capacitance  or  resistance   type

 

         only), tubing and air sets and junction boxes  air filter

 

         regulator, local position indicator, volume booster, fail

 

         freeze type IP Converter  etc. shall be provided as per the 

 

         requirements. All positioners shall be Smart Type. All field

 

         instrument mounted on the Control Valve shall be IP- 65.

 

 

8.07.00  TEST AND EXAMINATION

 

 

8.07.01  All  valves  shall  be tested  in  accordance  with  the 

 

         quality  assurance programme agreed between  the  MPPGCL

 

         and  contractor which shall meet the requirements of  IBR

 

         and  other applicable codes mentioned elsewhere  in  the 

 

         specifications.   The  tests shall include  but  not  be

 

         limited to the following:-

 

 

      1) Non Destructive Test as per ANSI B-16.34

 

      2) Hydrostatic  shell Test in accordance with ANSI B  16.34

 

         prior to seat leakage test.

 

      3) Valve  closure test and seat leakage test in  accordance 

 

         with ANSI-B 16.34 and leakage class test as per ANSI/FCI

 

         70.2.1998.

 

      4) Functional  Test : The fully assembled valves  including

 

         actuators  control  devices  and  accessories  shall  be

 

         functionally  tested to demonstrate times from  open  to

 

         close position.

 

 

      5) CV  Test: CV & FL(Liquid Pressure Recovery Factor) test

 

         shall be carried out as type  test  on each  size, type

         and  design of the valves  as  per  ISA 75.02 standard.

         The above tests shall be witness by MPPGCL.

        

8.07.02       Bidder shall submit material test certificate, Radiographic Evaluation report, ultra sonic test report, heat treat report etc. as per IBR/ASME for review and approval along with Factory Acceptance Test Report.

 

8.08.00  Bidder shall furnish all the control valves as finalised

         during    detailed   Engg.stage   without   any    price

 

         repercussions   whatsoever  depending  on  the   process

 

         requirements  including the systems under SG C&I and  TG

 

         C&I.  All the control valves provided by the bidder  for

 

         this project shall meet the specifications  requirements

 

         specified  herein.  Specification for control valves  in

 

         this  section  has to be read in conjunction  with  other

 

         relevant sections of the specification for this project.

 

 

8.09.00  Bidder  shall provide all type of gasket, gland  packing  

         with each control valves as spare.