Design Features and Operating Concepts - Lesman

1 Page 6105 Page 6105 Page 6105 Page 6105 Page 6105 Maxon Maxon Maxon Maxon Maxon VVVVV alvalvalvalvalvesesesesesDesign Features and Operating ConceptsDesign Features and Operating ConceptsDesign Features and Operating ConceptsDesign Features and Operating ConceptsDesign Features and Operating ConceptsVVVVV alvalvalvalvalves with electro-mechanical actuatorses with electro-mechanical actuatorses with electro-mechanical actuatorses with electro-mechanical actuatorses with electro-mechanical actuatorsfor quick opening or closing actionfor quick opening or closing actionfor quick opening or closing actionfor quick opening or closing actionfor quick opening or closing action1/99 Normally closed shut-off valvesNormally closed shut-off valvesNormally closed shut-off valvesNormally closed shut-off valvesNormally closed shut-off valves are used inburner system fuel supply lines on industrial boilers,furnaces, ovens, kilns, and other heating valves are designed to shut-off fuel automaticallyand instantly with any interruption in the electricpower supplied through your safety valves are also used for the manualmanualmanualmanualmanual ormotorizedmotorizedmotorizedmotorizedmo torized opening or closing of pipe lines carryinggases and liquids commonly used in industrial proc-esses.

2 Normally closed valves cannot be opened untilthe interlocking safety control circuit is proven andresulting electrical power is supplied to the automatic valve actuatorsMotorized automatic valve actuatorsMotorized automatic valve actuatorsMotorized automatic valve actuatorsMotorized automatic valve actuators are usedwhere remote access or unmanned applications : NOTE: NOTE: NOTE: NOTE: Valve motors are protected against thermaloverload. Normal duty cycles of 1 cycle per minute orless should allow motor thermal overload to suffi-ciently cool between cycles. If the normal valve dutycycle is exceeded, the motor must be allowed to coolbefore the thermal protection will automatically reset actuatorsManual reset actuatorsManual reset actuatorsManual reset actuatorsManual reset actuators require Operating person-nel to be physically present to actuate the valve fromits at rest open vent valvesNormally open vent valvesNormally open vent valvesNormally open vent valvesNormally open vent valves are most often usedas the bleed valve in a block-and-bleed pipe train,sometimes required by insurance authorities.

3 Theyare designed to open a vent line automatically andinstantly upon any interruption in the electric powersupply through your safety control normally open valves are also used inprotective atmosphere systems and other gaseousand fluid service requiring quick opening or by-passpurging the normally closed versions, both automaticand manual reset actuators are available for remoteaccess locations, or when Operating personnel'sphysical presence is Maxon valves feature one-piece cast iron orAll Maxon valves feature one-piece cast iron orAll Maxon valves feature one-piece cast iron orAll Maxon valves feature one-piece cast iron orAll Maxon valves feature one-piece cast iron orcast steel bodiescast steel bodiescast steel bodiescast steel bodiescast steel bodies with micro-lapped seats and through flow path minimizes pressure dropthrough full open swinging gate or rising stem (guillo-tine action)

4 6106 Page 6106 Page 6106 Page 6106 Page 6106 Maxon Maxon Maxon Maxon Maxon VVVVV alvalvalvalvalvesesesesesVVVVV alvalvalvalvalve Body Design Detailse Body Design Detailse Body Design Detailse Body Design Detailse Body Design DetailsTo provide seals in your process service lines, Maxon usestwo different styles of valve bodies:Rising stem (guillotine action) bodiesRising stem (guillotine action) bodiesRising stem (guillotine action) bodiesRising stem (guillotine action) bodiesRising stem (guillotine action) bodies are frequently usedin normally closed and normally open gas valves. The micro-lapped, spring loaded guillotine disc gets a pressure assist fromthe flowing gases to seal against the downstream micro-lappedmetal seat ring.

5 The carefully machined seal surfaces andextremely close tolerances of the valve body Operating mecha-nism promote positive closing action. Frequent cycling actionconstantly shears accumulated dirt or residue from the disc andseat to insure instantaneous and reliable location of the port in the disc is the basic differencebetween normally open and normally closed valve bodies. Bothvalves function by the top assembly mechanism driving the stemand disc down into the valve body, opening (or closing) the flowpath. Both valves trip to their rest position when their topassembly's compression spring is released to pull the stem andconnected disc up out of the gate bodiesSwinging gate bodiesSwinging gate bodiesSwinging gate bodiesSwinging gate bodies are frequently used in normally closedoil valves and for some non-combustible gas applications.

6 Thisdesign provides the same seal capabilities, but in a slightlydifferent Operating mode. The hard faced micro-lapped seat nutis threaded into the one-piece valve body. The free-floating, hardfaced, spring loaded circular disc swings across the seat. Linepressure also assists in sealing the disc to the downstream again, frequent use and cycling actually helps to keepyour valve clean. Since the free-floating disc is swinging acrossthe circular seat nut on the arc created by the disc carrier, thedisc rotates slightly on every cycle. This provides a fresh, cleansurface area for sealing off the flow valve bodiesMaxon valve bodiesMaxon valve bodiesMaxon valve bodiesMaxon valve bodies have special service trim optionsavailable to meet your particular fluid service your Maxon representative for BodyValve BodyValve BodyValve BodyValve BodyAssemblyAssemblyAssemblyAssemblyAsse mblyValve BodyValve BodyValve BodyValve BodyValve

7 BodyAssemblyAssemblyAssemblyAssemblyAsse mblySeatSeatSeatSeatSeatSeatSeatSeatSeat SeatNormally-ClosedNormally-ClosedNormal ly-ClosedNormally-ClosedNormally-ClosedD iscDiscDiscDiscDiscNormally-OpenNormally -OpenNormally-OpenNormally-OpenNormally- OpenDiscDiscDiscDiscDiscDiscDiscDiscDisc DiscCarrierCarrierCarrierCarrierCarrierD iscDiscDiscDiscDiscPage 6107 Page 6107 Page 6107 Page 6107 Page 6107 Maxon Maxon Maxon Maxon Maxon VVVVV alvalvalvalvalvesesesesesVVVVV alvalvalvalvalve Body Capacities/Specificationse Body Capacities/Specificationse Body Capacities/Specificationse Body Capacities/Specificationse Body Capacities/Specifications2/00 Table 2: Normally open valve bodiesTable 2: Normally open valve bodiesTable 2: Normally open valve bodiesTable 2: Normally open valve bodiesTable 2: Normally open valve bodiesTable 1: Normally closed valve bodiesTable 1: Normally closed valve bodiesTable 1: Normally closed valve bodiesTable 1: Normally closed valve bodiesTable 1: Normally closed valve bodiesEach complete valve assembly must include one ofthese valve bodies, regardless of ultimate through the valve body and resulting pres-sure drops may be estimated by inserting yourspecific conditions into the following formula andusing Cv flow factors given for each valve :Gases:Gases:Gases:Gases.

8 Q = (1360) x (Cv) x(P1+P2)(P1 P2)G Tf2 Liquids:Liquids:Liquids:Liquids:Liquids: V = (Cv) x(P1 P2)GfWhere:Where:Where:Where:Where:G = Gas specific gravity (air = )Gf= Specific gravity @ flowing temperature FP1= Inlet pressure PSIA ( psi + psi gauge)P2= Outlet pressure PSIA ( psi + psi gauge)Q = Cubic feet per hour @ PSIA and 60 FTf= Flowing temperature absolute (460 + F)V = Flow in gallons/minute of waterxNOTE: NOTE: NOTE: NOTE: NOTE: Typically, pressure drop for gas flows should notexceed 10% of inlet pressure; however, for 2" and smallervalves, the drop should not exceed 5 PSIG, and for " andlarger valves, must not exceed valve size on basis of the lowerlowerlowerlowerlower of these parametersto avoid critical flow )sehcnini(vCrotcaFydoB]1[ ]1[ydobevlavetaGgnigniwS= )

9 Sehcnini(vCrotcaFydoB]1[ 6108 Page 6108 Page 6108 Page 6108 Page 6108 Maxon Maxon Maxon Maxon Maxon VVVVV alvalvalvalvalvesesesesesVVVVV alvalvalvalvalve Body Capacitiese Body Capacitiese Body Capacitiese Body Capacitiese Body Capacitieswith Naturwith Naturwith Naturwith Naturwith Natural Gas at 5 inches wal Gas at 5 inches wal Gas at 5 inches wal Gas at 5 inches wal Gas at 5 inches Inlet Pressure Inlet Pressure Inlet Pressure Inlet Pressure Inlet PressureApproximateApproximateApproximat eApproximateApproximate pressure dropsfor various valve sizes and flowsmay be determined by using , pressure drop forfuel flows should not exceed10% of inlet valve size on basis ofthe lowerlowerlowerlowerlower of these parametersto avoid critical flow " & 1" " & 1" " & 1" " & 1" " & 1" " " " " " " " " " " RS20 Cv20 Cv20 Cv20 Cv20 Cv45 Cv45 Cv45 Cv45 Cv45 Cv53 Cv53 Cv53 Cv53 Cv53 Cv86 Cv86 Cv86 Cv86 Cv86 Cv127 Cv127 Cv127 Cv127 Cv127 Cv173 Cv173 Cv173 Cv173 Cv173 Cv304 Cv304 Cv304 Cv304 Cv304 Cv423 Cv423 Cv423 Cv423 Cv423 Cv490 Cv490 Cv490 Cv490 Cv490 Cv719 Cv719 Cv719 Cv719 Cv2" RS2" RS2" RS2" RS2" " " " " " RS3" RS3" RS3" RS3" RS3" " CP " CP " CP " CP " CP RS3" CP RS3" CP RS3" CP RS3" CP RS3" CP RS4" CP RS4" CP RS4" CP RS4" CP RS4" CP)

10 RS6" RS6" RS6" RS6" RS6" RS4" HC4" HC4" HC4" HC4" HC6" HC6" HC6" HC6" HC6" HC1172 Cv1172 Cv1172 Cv1172 Cv1172 Cv869 Cv869 Cv869 Cv869 Cv869 CvPPPPPage 6109age 6109age 6109age 6109age 6109 Maxon Maxon Maxon Maxon Maxon VVVVV alvalvalvalvalvesesesesesVVVVV alvalvalvalvalve Body Capacitiese Body Capacitiese Body Capacitiese Body Capacitiese Body Capacitieswith Natural Gas at 1 PSIG Inlet Pressurewith Natural Gas at 1 PSIG Inlet Pressurewith Natural Gas at 1 PSIG Inlet Pressurewith Natural Gas at 1 PSIG Inlet Pressurewith Natural Gas at 1 PSIG Inlet Pressure1/99 Approximate Approximate Approximate Approximate Approximate pressuredrops for various valvesizes and flows may bedetermined by using , pressure dropfor fuel flows should notexceed 10% of valve size onbasis of the lowerlowerlowerlowerlower of theseparameters to avoid criticalflow " & 1" " & 1" " & 1" " & 1" " & 1" " " " " " " " " " " RS2