Flowserve Noble Alloy Piston Check IOM - Manual (Page 3)

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1.0 Flowserve/Noble Alloy Valve Piston Check Valve Repair Instructions
If there is any question of the integrity of the parts within the valve to be repaired, the
valve should be returned to Flowserve/Noble Alloy Valve for factory repairs.
Please refer to Section 2.0 drawing for identification of parts described in the
instructions.
DISASSEMBLY
Locate the valve in a vise or suitable fixture with the Piston (4) side facing up. Using
Noble special tool (available for purchase from Flowserve), unscrew the seat ring (5) in a
counter-clockwise direction and remove. Heat may be applied to the seat ring to loosen
the factory Loctite
Ò. Do not exceed 400°F.
CAUTION! The Piston is under some spring load and may pop out of the valve. Be
sure to restrain the Piston until the Seat is removed.
Once the Seat is removed, remove the Piston (4), Spring (3) and Cage (2) from the Body
(1). The Cage may require a few taps from the back to break it loose. Some cages will
be tack welded to the body. The welds will have to be ground through to remove the
cage. Clean all the parts thoroughly for inspection.
INSPECTION
Inspect the Seat threads for any damage. Inspect the seal face for nicks, grooves,
mushrooming, or signs of corrosion. If the Seat has a soft face insert, inspect it for the
same types of damage. It is recommended that the Seat be replaced during a repair for
optimum performance.
CAUTION! If the Seat has been Nobleized, it cannot be resurface or the Nobleized
surface will be damaged or removed. Nobleized parts must be returned to the factory for
refurbishing and Re-Nobleizing. Seats that are repaired and not Re-Nobleized will have
significantly reduced service life.
Inspect the Piston face for nicks, grooves, mushrooming or signs of corrosion. Inspect
the Piston shaft for scoring and wear. The Piston shaft should slide in and out of the
Cage bore easily. If the Piston is damaged, it should be replaced with a new Seat as a
set. CAUTION! If the Piston has been Nobleized, it cannot be resurfaced or the
Nobleized surface will be damaged or removed. Nobleized parts must be returned to the
factory for refurbishing and Re-Nobleizing. Pistons that are repaired and not Re-
Nobleized will have significantly reduced service life.
Inspect the Spring for nicks on the coils and for sign of significant corrosion. If it shows
any sign of damage it should be replaced. It is recommended that the Spring be
replaced during a repair for optimum performance.
Inspect the Cage for nicks, grooves or signs of corrosion. Inspect the Cage Piston shaft
bore for scoring and wear. The Piston shaft should slide in and out of the Cage bore
easily. If the Cage arms show significant wear, it should be replaced. CAUTION! If the
Cage has been Nobleized, it cannot be resurfaced or the Nobleized surface will be