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

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1.0 Flowserve/Noble Alloy Valve Swing Check Valve Repair Instructions
1. Remove the bonnet nuts (9) with a wrench and lift the bonnet off the valve. The bonnet seal (5)
may remain in the bonnet or fall loose when you remove the bonnet. Discard the seal. IT IS
NOT RECOMMENDED THAT BONNET SEALS BE REUSED. Inspect the seal groove in the
bonnet and body seal area for corrosion, wear, or any other visible damage. If the seal groove
in the bonnet or the seal face on the body is damaged, it is recommended that the valve be
returned to Flowserve-Noble Alloy Valve for repair.
2. Lift the arm/disc assembly (3A, 3B, 3C) out of the valve. Be careful not to damage the disc seal
area. (If the valve is being disassembled for welding in line, set the assembly aside being
careful the hinge pin (4) does not fall out of the arm and become lost.). Inspect the disc and
seat area in the body for nicks or scoring. If the body seat is damaged, it is recommended that
the valve be returned to Flowserve-Noble Alloy Valve for repair. Inspect the disc (and TFE
insert if soft seated) and replace if worn or damaged. The disc/arm assembly must be
replaced as an assembly. Minor wear or damage can be lapped out and the disc reused. DO
NOT LAP NOBLEIZED DISCS. The disc should be loose on the arm and should gimbal freely.
If it does not move freely, the assembly must be replaced. The TFE insert (if present) can be
removed with a seal puller and a new insert rolled into the groove in the disc. Lap or machine
the new soft seal to make it uniform and flat. Inspect the pin (4) and if it is bent or worn, it
should be replaced. Inspect the pin hole in the arm (3B) for excessive wear and replace if too
worn. The pin should be loose in the pin hole however.
3. After the valve parts have been thoroughly cleaned, the valve can be reassembled. If the valve
has been welded into place, be sure the inside of the valve is free of dirt, oil, weld spatter, etc.,
and that the valve has completely cooled before reassembling. Place the arm/disc assembly
(3A, 3B, 3C) into the valve making sure the hinge pin rests full in the pin slot in the body. The
pin should be able to move loosely in the slot.
4. Place a new bonnet seal (5) in the seal groove in the bonnet and place the bonnet over the
studs and onto the valve. Be sure the seal ring does not fall out of the seal ring groove. Install
the nuts on the studs (8) and torque according to the following chart. Pressure test per ANSI
specifications.