Flowserve Valtek Mark 14 - Manual (Page 10)

Valtek Mark 14 Control Valves FCD VLENIM0115-00 – 06/06
10
7 Reassembly and Installation
7.1 Before re-assembly, carefully inspect the body pressure seal sealing surfaces. These are the
cylindrical surfaces just beneath the and seat retaining ring grooves. If these surfaces are
damaged, they must be reworked to provide a 32 Ra surface finish. Also ensure that the body
shelf that supports the seat ring is free from damage and is clean.
7.2 If the MegaStream plate has been removed from the body, place the plate in the end of the
body with the boss facing the body gallery. Thread in the plate retainer tightly against the plate
and heavily peen the threads to prevent the retainer from unscrewing during service.
7.3 If the seat assembly has been disassembled, index the severe service trim into the seat ring.
7.3.1 Liberally apply thread locking compound (Loctite Blue or equivalent) on the threads of
the seat assembly bolts and thread them into the seat ring. Using Table 1, tighten the
bolts to the values according to the bolt material.
Table 1 – Severe Service Trim Bolt Torque Values
Bolt Size
Bolt Material
Inconel A193 B7/B16 A193 B8
inches ft-lb N m ft-lb N m ft-lb N m
3 ⁄
8
24 32.5 19 25.8 15 20.3
7 ⁄
16
39 52.9 31 42.0 23 31.2
1 ⁄
2
60 81.3 48 65.1 36 48.8
9 ⁄
16
87 118 70 94.9 52 70.5
5 ⁄
8
121 164 97 132 72 97.6
3 ⁄
4
216 293 173 235 129 175
All values are +/- 10%
7.3.2 Check the alignment of the seat ring and stack by inserting the plug into the seat
assembly and moving it back and forth, checking for sticking or binding.
7.3.3 Tack-weld each socket head bolt with a compatible weld material. Weld near the OD of
the severe service trim to facilitate the ease of removing the weld later.
7.4 Lower the entire seat assembly into the body with threaded lifting rings in the seat ring.
NOTE: It is critical that the severe service stack centers and indexes over and around the boss located
on the MegaStream plate.
7.5 Carefully install the pressure seal into the body and around the seat ring. Mark 14 pressure
seals have three metal anti-extrusion rings on the seal corners. The side of the seal with two
metal rings must face up when installed. See Figure 2 to determine the correct installation
position.