Flowserve Marathon-Mach 1 - Manual (Page 10)

10
Flow Control Division
Section 1.0
1. Normal procedures for field replacement of port seals or
sleeves are to be followed. Refer to V-A, steps 1-5, and
V-B, steps 1-8.
2. The fireseal top seal assembly differs from the standard
Marathon-Mach 1 top seal and is completed per the
following instructions.
3. 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 is to be flared on the diaphragm guide (Part
Series BY86272A) just enough to slip over the plug stem.
FIGURE VI-1
4. The PFA diaphragm is turned over and placed over the
plug stem with the lip down using the diaphragm guide.
FIGURE VI-2
5. Remove the diaphragm guide. The metal diaphragm is
placed over the plug stem just far enough to enlarge the
ID to conform to the plug stem and then removed.
6. The metal diaphragm is removed from and replaced on
the plug stem with the ID lip down.
7. The Grafoil packing ring is placed over the stem.
FIGURE VI-3
SECTION VI
ASSEMBLY SPECIFICATIONS - FIRESEAL VALVES 1"- 6" MARATHON-MACH 1
FIGURE VI-1
FIGURE VI-3
FIGURE VI-2
Place PFA diaphragm over plug
stem with lip down.
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.