Valtek MegaStream Control Valves.pdf - PRO-QUIP

Bonnet(Item No. 40)Sleeve Gasket(Item No. 56)Bonnet Gasket(Item No. 58)Body(Item No. 1)Seat Ring(Item No. 20)Bonnet Flange Bolting(Item No. 108/114)Bonnet Flange(Item No. 70)Sleeve(Item No. 31)Attenuator(Item No. 30)Plug Seals(Item No. 65)Plug(Item No. 50)Seat Ring Gasket(Item No. 55)Figure 2: Pressure-balanced MegaStream AssemblyNOTE: Item numbers correspond directly to valve's bill of material. Refer to it for specific part numbers.seated, metal-to-metal, in the body. This can beeasily felt through the wrench.9. Slowly stroke the plug up and down to check thealignment of the plug with the attenuator.Disassembling Pressure-balancedMegaStreamRefer to Figure 2 and proceed as follows:WARNING: Depressurize line to atmospheric pressureand drain all fluids before working on thevalve. Failure to do so can cause serious injury.1. Fully retract plug until indicator is pointing to theopen position.2. Remove bonnet flange bolting and lift the actuator,bonnet and plug out of the valve body. A hoist maybe necessary for larger valves.WARNING: A hoist may be necessary for largeractuators (size 50 and larger). Care must betaken to lift the actuator and plug straight out ofthe valve body. Any scraping of parts whileremoving the actuator may damage valve parts.When the actuator is not equipped with a liftingring, do not attach one; instead, lift the actuatorby using lifting straps through the yoke legs. Inthis case, the center of gravity may be above thelifting point. Therefore, support must be given toprevent the actuator from rotating; otherwise,serious injury may result.WARNING: Danger exists in removing the actuator,bonnet and plug–especially if PTFE pressure-balancedseals are used. The attenuatorsleeve may stick to the plug and fall duringdisassembly, causing possible serious injuryand/or damage to the valve or nearby equipment.Steps 3 thru 6 must be followed before attemptingto remove the plug from the sleeve.3. If the sleeve is observed sticking to the plug duringFlowserve Corporation, Valtek Control Products, Tel. USA 801 489 861118-3