Instruction Manual
D100425X012
YD and YS Valves
July 2017
13
CAUTION
Never use an old stem with a new valve plug. The use of an old stem requires drilling a new pin hole through the stem (or
adaptor, in case an ENVIRO‐SEAL bellows seal bonnet is being used). This drilling weakens the stem or adaptor and may
cause failure in service. However, a used valve plug may be reused with a new stem or adaptor.
Locate the pilot hole in the valve plug and drill the hole through the plug and stem assembly (determine drill size from
table 4). Drive in the pin to lock the assembly.
8.
For ENVIRO‐SEAL bellows seal bonnets
, grip the flats of the stem extending out of the top of the bellows shroud
with a soft‐jaw chuck or other type of vise. Screw the valve plug/adaptor assembly onto the valve stem. Tighten as
necessary to align the pin hole in the stem with one of the holes in the adaptor. Secure the adaptor to the stem with
a new pin.
CAUTION
To prevent possible damage to the seal ring and cage seal, exercise care in the following procedure.
9. Place the upper cage (key 3A) over the plug assembly, being certain not to damage the seal ring, and lower this
entire assembly into the valve. Due to the close fit between the valve body bore and the cage seal, it will be
necessary to apply a steady force to the top of the cage for final positioning inside the valve body bore. Take care to
ensure that the upper cage slips into the lower cage and the cage seal is not damaged.
10. Place the spiral wound gasket (key 11), shim (key 22), and bonnet gasket (key 9), respectively, over the upper
cage.
11. Mount the bonnet onto the valve with the lubricator or pipe plug parallel with the pipeline.
Note
Stud(s) and nut(s) should be installed such that the manufacturer's trademark and material grade marking is visible, allowing easy
comparison to the materials selected and documented in the Emerson/Fisher serial card provided with this product.
WARNING
Personal injury or damage to equipment could occur if improper stud and nut materials or parts are used. Do not operate or
assemble this product with stud(s) and nut(s) that are not approved by Emerson/Fisher engineering and/or listed on the
serial card provided with this product. Use of unapproved materials and parts could lead to stresses exceeding the design
or code limits intended for this particular service. Install studs with the material grade and manufacturer's identification
mark visible. Contact your Emerson Automation Solutions representative immediately if a discrepancy between actual
parts and approved parts is suspected.
