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b
Using the measured torque amount, increase the torque wrench setting by 20in-lbs.
c
Re-torque 3 to 5 of the bolts around the leak. Repressure test the valve.
d
If the valve still leaks, this step can be done once more.
e
If the valve still leaks after the second attempt, the Vane Seat Ring may need
replacement.
Valve Sizes
Vane Ring Bolt Wrench Size
Max Vane Ring Torque
3” thru 12”
7/16” Hex Head Bolt
150in-lbs
14” thru 24”
9/16” Hex Head Bolt
220in-lbs
30” thru 54”
7/32 Allen Key Bolt
220in-lbs
60” thru 72”
9/16” Hex Head Bolt
220in-lbs
SECTION 5.3 – VANE SEAT RING REPLACEMENT
M&H BFV’s design complies with the AWWA C504 Appendix guidance that “permits field adjustment
or replacement of rubber seats when leakage occurs past the disc.” So, if an M&H rubber seat becomes
damaged or badly worn, field replacement of the rubber seat can be accomplished with relative ease. The
rubber seat can be replaced without removal of the shaft & vane assembly. This can be accomplished at
the installation site for all valve sizes with standard tools. Assuming the maintenance staff can safely
access the Vane Seat Ring side of the valve, this can be done with the valve still in the line.
Section 5.3.1.1 – 3” thru 24” REMOVAL OF EXISTING VANE SEAT RING
1.
With vane in the closed position, remove seat retention screws.
2.
Open valve approximately 20 degrees to remove the seat. NOTE: For 3” thru 24” valves, the Vane
Ring Rubber is molded to the stainless-steel insert. They are one unit and can only be removed from
the valve as one piece.
3.
Lift the near side seat edge up from the seat recesss area and, using a rubber mallet or hammer &
block of wood, tap lightly on the seat edge to bump the Vane Seat Ring away from the recess area of
the vane.
4.
Gently work the Vane Seat Ring free, keeping in mind that resistance may be encountered at areas of
contact near the shaft locations. (Forcible removal may damage the seat and prohibit reuse, if
desired.)
5.
Clean any debris, grease, or coating material from seat recess on vane and from stainless steel
seating surface in the valve body.
Section 5.3.1.2 – 3” thru 24” INSTALLATION OF NEW SEAT
1.
With the existing vane seat ring removed and the seating area cleaned of any debris and raised (or
rough) surfaces smoothed, move the vane to the close position. Make sure the vane is level in the valve
body. (If vane is not level, refer to Section 5.5 – VANE LEVEL ADJUSTMENT)
2.
Fully lubricate the stainless-steel body seat with an NSF61 approved grease or pipe lubricant. Use
extra lubricant at contact area near the shaft locations. Fully lubricate the rubber portion of the new
Vane Seat Ring. Lay the Vane Seat Ring on vane, aligning the vane ring bolt holes in the vane and seat
