5
VLENIM0006-03 (AQ) July 2019
Gland Flange
Bolt and Nut
(Item Nos. 107,118)
Packing Set
(Item No. 88)
Gland Flange
(Item No. 80)
Upper Stem Guide
(Item No. 87)
Bonnet
(Item No. 40)
Bonnet Flange
(Item No. 70)
Bonnet Gasket
(Item No. 58)
Plug Head Guide
(Item No. 65)
Plug
(Item No. 50)
Seat Ring
(Item No. 20)
Seat Ring Gasket
(Item No. 55)
Bonnet Flange
Stud and Nut
(Item Nos. 108/1
Packing Spacers
(Item Nos. 94–99)
nti-Extrusion Spacer
(Item No. 93)
Lower Stem Guide
(Item No. 82)
Body
(Item No. 1)
Figure 3: Mark Six contol valve
Item numbers correspond to the valve’s bill of material. Refer to it for specic part numbers.
CAUTION: Do not allow plug to rotate. Leave two or three
threads exposed for air-to-close valves. For air-to-open valves,
screw the plug stem as far as it will go into the actuator stem.
7. Assemble yoke clamp or tighten the yoke bolts.
8. Cycle the valve to retract the plug.
9. The plug head seals, when used, make it necessary to drive the
plug into the body using the actuator. Partially bolt down the bonnet
ange and supply air to upper actuator port to extend the plug.
Repeat operation, if necessary, to bring bonnet fully down into
the body.
10. Tighten two opposing bonnet bolts one-sixth turn. Tighten all
bonnet bolts one-sixth turn at a time, alternating between opposing
bolts. Firmly tighten all nuts evenly and completely, using full
wrench force to compress the gasket and seat the bonnet metal-
to-metal in the body. Recommended bonnet bolting torques are
given in Table 3.
CAUTION: Insufcient bonnet bolt tightening will result in
improper gasket compression.
To Next Page
Loading...
