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Wallace W. ToddSystem Valve Services, Inc.Lincolnton, NCwww.svsinfo.comSystem Valve Services, Inc.System Valve Services, Inc. 12Gas employees must follow thecompany’s written O&M policiesand procedures. Those policiestake precedent.There is no “perfect” valve. Allvalves require some type ofmaintenance, regardless of what amanufacturer may say.Improper valve selection cannotbe overcome by propermaintenance practices. Selectionconsiderations includeenvironment, pressuredifferential when closed, andservice application.System Valve Services, Inc.VALVE MAINTENANCE FOR NATURALGAS OPERATORS31

1st. Century, BCSystem Valve Services, Inc. 4Valve (valv), n – a mechanical device that is usedto control a liquid or a gas in a piping system.Most gas valves operate in a “clockwise closed”manner. (With stops.)There are different valve types with operatingcharacteristics that vary from manufacturer tomanufacturer.In order to operate & maintain a valve properly, atechnician must know the mechanics of the valveand the consequences involved.More grease or a bigger wrench isn’t always theanswer!If you experience leakage, make sure the valve isfully closed!System Valve Services, Inc.5 What kind of valve is it? Three major valve designs are used in the gasindustry. (Ball, Gate, Plug) How does it operate? Number of turn(s) to close? Is it clockwise-turn to close? What does it serve? Operating the valve fully. Is it open or closed?What is the maintenance requirement?Does it operate properly?Are there any unusual problems?Can you use a search engine?System Valve Services, Inc.VALVE MAINTENANCE FOR NATURALGAS OPERATORS62

Sealants are designed to provide primary orsecondary sealing, depending on valve type.Cleaners are designed to flush or removedebris from valve internals.Lubricants are designed to displacemoisture, provide lubrication to seatassemblies, and prevent corrosion.Sealants vary in texture, temperature range,and application.Each is introduced into a valve by usingsealant injection equipment such as a handgun.Improper selection can hinder valveperformance.System Valve Services, lweldClimax950No. 80Total-lube 911950VXXValve FlushValve CleanerVCSSystem Valve Services, Inc. 8In plug valves, cleaners are used to softenold and hardened sealant that is clogged inthe sealant chambers. This dried sealantwill increase turning torque.In ball valves, cleaners are used to removedeposits that adhere to the ball and affectseating performance. Cleaners do not havethe same characteristics as sealant.Cleaners will evaporate over time. Withweakened sealant remaining, a plug valvewill eventually leak if new sealant is notinjected.System Valve Services, Inc.VALVE MAINTENANCE FOR NATURALGAS OPERATORS93

A quarter-turn valve.Two types, cylindrical and tapered.Tapered plug, reduced port. (60% - 70%)Sealant serves as sealing element.Requires maintenance.Several designs and pressure classes.Reliable downstream shut-off when properlymaintained.System Valve Services, Inc.10Sealant FittingWrench SquareGlandInternal CheckCoverPlugBodySystem Valve Services, Inc. 11Don’t use a pipe wrench or tool that has serratedteeth. The material will weaken over time whena pipe wrench is applied.Clean the sealant stem face and giant buttonhead coupler before lubricating valve. For properlubrication, the valve must be fully open or fullyclosed.When injecting sealant into the valve, monitorthe injection pressure using the gauge on thegun. Be sure not to over pressurize the sealantsystem or damage can result.System Valve Services, Inc.VALVE MAINTENANCE FOR NATURALGAS OPERATORS124

Cycle the valve completely if possible afterlubrication. If not, cycle about 45 degrees so thesealant will spread evenly within the valve.If the valve is hard to turn or seized, and thesealant injection pressure is acceptable, theproblem is likely to be exterior corrosion aroundthe operator and / or gland. Applying excessiveturning torque can possibly damage the valve!Look for abnormal conditions that can affectperformance or be a safety concern. System Valve Services, Inc. Corroded BonnetBolt & NutCorroded Gland StudNutSystem Valve Services, Inc. 1314“Topping Off” of the sealant system should beperformed on a routine basis. Usually 20% - 25% of thesystem capacity.Injection pressure will vary with sealant type, ambienttemperature, valve condition and size.When the injection pressure climbs, plateaus, then fallsquickly, the valve is properly lubricated.If the pressure continues to climb, a blockage exists,either in the plug, or the sealant fitting.If the pressure never reaches a plateau, the valve eitherneeds additional sealant, or the plug adjustment is tooloose.System Valve Services, Inc.VALVE MAINTENANCE FOR NATURALGAS OPERATORS155

Calculate the sealant capacity of thevalve.Inject the cleaner into the valve andcycle a couple of times if possible. Reinject if needed. Allow to remain in thevalve until desired results are reached.Follow-up with re-lubrication of valve.When new sealant is injected into thevalve after the cleaner, the old sealantwill be forced into the pipeline. System Valve Services, Inc. 16PLUG VALVES 4” Valve & Smaller – 1 oz. / inch size 6” Valve – 12 “ Valve – 1.5 oz. / inch size Greater than 12” Valve – 2 oz. / inch sizeHIGH PRESSURE HYDRAULIC HANDGUN 1/16th oz. / stroke 8.2 oz. / “J” Stick 8.2 oz. / Gun PackEXTENDED SEALANT LINES ¼” Pipe – 0.5 oz. / foot length ½” Pipe – 1.5 oz. / foot lengthSystem Valve Services, Inc.17If the sealant fitting must be replaced, use cautionwhen removing it. a. Defective internal ball check fitting can cause gasleakage. Wiggle the fitting as you remove it as amethod of insuring that the check fitting is secure.b. Seized threads can strip out the internal threads ofthe stem. Use penetrating oil and proceed slowly ifseized threads are encountered.c. Do not allow debris to fall into stem opening.d. Replace the fitting with one of identical length.e. Screw the fitting into the stem opening completely.System Valve Services, Inc.VALVE MAINTENANCE FOR NATURALGAS OPERATORS186

Most newer Class 150 styles have noadjustment.Adjusting a plug is usually not required ifthe surrounding environment or productmedium remains constant. Don’t confusea plug “set” for a seized plug.If an adjustment is required, fine tuningshould be at no more than 15 degreeincrements and should be done evenlywhen multiple gland cover bolts areinvolved.Loosening a plug too much willcompromise the ability of the valve to sealoff when closed.Be sure to check for leakage and anycycling irregularity. 19System Valve Services, Inc.20A quarter-turn valve.Both full & reduced port.Three basic styles: System Valve Services, Inc.FloatingTrunnionHybridThe sealing mechanism is a stainless steel ballor plated ball, mating with a Teflon, Viton orsimilar material seat ring.May have secondary sealing system.Several designs and pressure classes.Wide variety in price based on application.System Valve Services, Inc.VALVE MAINTENANCE FOR NATURALGAS OPERATORS217

When closed, theball pivots forwardto the downstreamseat in order tomake the seal.When the valve isclosed, the pressuredifferentialdetermines thebreakaway torque.Maintenance free.Body design maylimit repair to valve.System Valve Services, Inc.22OperatorBonnet CapPackingStemBallSeatBodySystem Valve Services, Inc. 23Trunnion’s are short shaft extensions that holdthe ball in place so pressure differential haslittle effect on operating torque, excellenttransmission application.Secondary sealing system.Seating mechanism involves upstream anddownstream spring loaded seats in constantcontact with the ball, assisted by pipelinepressure.Block & bleed capability, a technique used todepressurize a valve body cavity in the openand / or closed position. Valve must be“double seated” and have a drainingmechanism.System Valve Services, Inc.VALVE MAINTENANCE FOR NATURALGAS OPERATORS248

Cameron - Self Relieving – Pressurebuild-up in the body cavity will increaseto a pressure that exceeds the springtension against the downstream seatassembly. The downstream seat willdisengage from the ball at 200 PSI andrelieve the body cavity pressure. Grove / Delta - Double PistonEffect – Allows both up anddownstream seats to seal against theball with pressure from the sameside of the valve in high pressureapplications. Seat springs performthis function in low pressureapplications (50 PSI).System Valve Services, Inc.25Cameron – Open or ClosedGrove / Delta – Closed Only Valve must be completely open or closed. Do notoperate valve with block & bleed fitting open.Open fitting to blow down body cavity pressure.Seat integrity can be verified.Downstream pressure can be safeguarded. Stem seal can be replaced. System Valve Services, Inc.26OperatorPacking BoxSeatsBallBodyTrunnionSystem Valve Services, Inc.VALVE MAINTENANCE FOR NATURALGAS OPERATORS279

OperatorStemSeatsBallBodyTrunnionSystem Valve Services, Inc.28Rising StemPacking BoxPacking FittingSeatBallBodySystem Valve Services, Inc.29System Valve Services, Inc.30VALVE MAINTENANCE FOR NATURALGAS OPERATORS10

Fittings are extended above groundalong with the valve actuator.Capped lube fittings are located atthe upstream and downstreampoints.Block & Bleed drain fitting islocated at the mid-section of thevalve.Capped stem lube fitting may belocated next to Block & Bleedfitting.System Valve Services, Inc.31Seat FittingBlock & Bleed FittingStem Fitting16” Cameron Valve; Santee Cooper Power; Iva, SCSystem Valve Services, Inc. 32Periodic cleaning is necessary to removepipeline dust and deposits from the seatingarea.Know the composition of the seat materialbecause cleaning may also include seatlubrication. (Nylon vs Buna or Viton)Use care when removing caps from any lubefitting. NEVER remove a fitting from apressurized valve. The hydraulic pressure required to inject acleaner into a ball valve should be just abovethe operating pressure within the valve unlessa blockage exists. Inject the cleaner into the valve. Cycle thevalve. Repeat this 2-3 times if severe debris issuspected. Block & Bleed the valve in order toverify results. System Valve Services, Inc.VALVE MAINTENANCE FOR NATURALGAS OPERATORS3311

BALL & GATE VALVES Most Valve Sizes – 0.5 oz. / inch size / seatHIGH PRESSURE HYDRAULICHANDGUN 1/16th oz. / strokeEXTENDED SEALANT LINES ¼” Pipe – 0.5 oz. / foot length ½” Pipe – 1.5 oz. / foot length System Valve Services, Inc. Use safety precautions when opening a block &bleed fitting. Be aware that pipeline liquids may betrapped in the body cavity.When removing seat sealant fitting caps; Clear cap vent holes of any paint or other debris.Don’t stand directly in front of fitting while removing thecap.Use a back-up wrench on the fitting while removing thecap.Do not remove the fitting from the valve while the pipelineis pressurized.System Valve Services, Inc. 3435Seats can “set up” if the valve has not beencycled for a long period of time, causing ahigher than normal initial break away torque.Lubricate the gear box with a standard lithiumor moly-type lube. Make sure water has notmigrated into the gear housing.Insure that valve stops are clear of debris thatcould prevent the valve from completelyclosing.System Valve Services, Inc.VALVE MAINTENANCE FOR NATURALGAS OPERATORS3612

If possible, fully cycle the valve so the ball isswept clean of debris.Ball valves are poor throttling valves becausedamage to the ball or seat will affectperformance. Keep the valve fully open whilein service.Don’t use excessive torque while operatingvalve or damage will result.Open the Block & Bleed fitting on a closedvalve when performing downstream repairs.System Valve Services, Inc.37Sealant, when used as a secondary sealingfeature, can be smeared along the ball anddamage or dislodge the seat when cycled. Flushthe seat with valve cleaner prior to cycling thevalve. Do not use a sealant enriched with PTFEparticles.Ball valves have very little tolerance betweenthe bore and the seat ring. If the valve has agear operator or actuator as the turningmechanism, be sure the stops are properly setand are completely closing the valve. One ortwo degrees from being fully closed can makethe difference between a proper seal off or not. System Valve Services, Inc. 38A multi-turn valve.Both full and reduced port.Have several different sealing features,depending on type of gate or wedge.May have secondary sealing features.Several designs and pressure classes.More expensive than quarter-turnvalve.System Valve Services, Inc.VALVE MAINTENANCE FOR NATURALGAS OPERATORS3913

Primarily used in distribution pressureapplications.A non-rising stem style does not allow forvisual verification of the gate position.Usually a metal to metal seat design bothupstream and downstream.Lower profile design than conduitcounterpart.System Valve Services, Inc.40Operator SquareGlandPackingBonnetStemWedgeBodySystem Valve Services, Inc.41 Cycle the valve fully if possible so the stem iswiped clean of any debris. Paint, pipeline dust,etc. can affect turning torque. Don’t use excessive torque or damage can result.Know the mechanics of the valve. Stem leakage is usually caused by ineffectivepacking. In most cases, the packing can bereplaced with the valve in the fully openposition. Improper packing adjustment can affect theoperating torque of the valve.System Valve Services, Inc.VALVE MAINTENANCE FOR NATURALGAS OPERATORS4214

Injects sealant at pressuresup to 10,000 PSI.Pressure gauge range from0 – 15,000 PSI.Internal relief valveprevents the overpressuring of the sealantbarrel (8,000 – 10,000 PSI).Hydraulic oil should beperiodically checked andreplenished.System Valve Services, Inc.43System Valve Services, Inc.44System Valve Services, Inc.45VALVE MAINTENANCE FOR NATURALGAS OPERATORS15

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Superman StatueMetropolis, IllinoisSystem Valve Services, Inc.VALVE MAINTENANCE FOR NATURALGAS OPERATORS5519