Flowserve G4 Marathon Sleeveline Plug Valves - Manual (Page 13)

13
1 / 2 "-4"
1. Normal procedures for field replacement of one piece
sleeves are to be followed for inserting the sleeve,
Section V A (
1 / 2 " & 3 / 4 "), steps 1-3 or Section V B (1"-8"),
steps 1-4.
2. Check that the inner diameter of the gasket pad of the
top cap has between a 1/16" x 45° to 3/32" x 45° cham-
fer. If not, remachine the top cap of this dimension. See
Figure V B-4, page 10.
3. The firesafe top seal
assembly differs from
the standard G4 top
seal and is completed
per the following
instructions.
4. The PFA diaphragm
(Part 6) is to be flared
on a diaphragm guide
just enough to slip
over the plug stem
(Figure VI-1).
5. The plug stem should
be checked for nicks
before installing the PFA
diaphragm. Nicks on
this surface could result
in scratches on the lip
of the diaphragm. The
PFA diaphragm (Part 6)
is placed over the plug
stem with the aid of the
G4 Marathon diaphragm
guide part series
BY86272A. The lip is
down (Figure VI-2).
Remove the guide.
6. The metal diaphragm
(Part 6A) is placed over
the plug stem and the
hole enlarged just
enough to slip down on
the stem (Figure VI-3).
7. The metal diaphragm
is then removed and
replaced with the lip
down (Figure VI-4).
8. The Grafoil packing ring
(Part 20) is placed over
the stem (Figure VI-5).
9. Using diaphragm guide
port # series P/N
BY86272A to protect
the o-ring from the
stem edge, install the
first o-ring by “rolling”
it with your fingers over
the guide and into the
lower stem groove
SECTION VI
ASSEMBLY SPECIFICATIONS – FIRESAFE VALVES G4Z MARATHON, G4ZR MARATHON
FIGURE VI-1A
TYPICAL ASSEMBLY OF G4Z MARATHON AND
G4ZHF MARATHON
®Grafoil is a registered trademark of Union Carbide Corporation
Flow Control Division
Section 1.0
WRENCH (13)
STOP COLLAR RETAINER (19A)
STOP COLLAR (19)
ADJUSTER FASTENERS (12A)
ADJUSTER (12)
TOP CAP FASTENERS (3A)
TOP CAP (3)
GROUNDING SPRING (17)
THRUST COLLAR (11)
TEFLON BACK-UP RINGS (22) &
O-RINGS (23)
PACKING GRAFOIL ® (20)
DIAPHRAGM –
STEEL OR MONEL (6A)
DIAPHRAGM –
PTFE, PFA, UHMWPE (6)
GASKET GRAFOIL ® (21)
PLUG (2)
SLEEVE (5)
BODY (1)
FIGURE VI-1
Flare PFA diaphragm over
tapered bar.
If damaged the
plug taper and
1" in length of
stem must be
repolished to a
surface finish of
16 on the taper
and stem.
FIGURE VI-2
Place PTFA diaphragm over plug
stem with lip down.
FIGURE VI-3
Flare metal diaphragm over plug
stem with lip up.
FIGURE VI-4
Metal diaphragm is removed and
reassembled with lip down.