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Hygienic butterfly valves model F250 & F251
Installation & Maintenance Instructions
6.9 Failures
Leakage along the disc stem or between the body halves 1.
Check seat 2.
Check product pressure (must be below 10 bar).
Leakage between body halves 1 and flanges 14 (butterfly valve wafer style).
Check flange seals 15.
Water hammer during closing.
Increase the closing time.
6.7 Assembling the butterfly valve
(See appendix B)
A - Stretch seat 2 over bottom of disc stem (short end), then place seat from disc along the upper
stem and rotate disc 3 to the open position
B - Place upper and lower bearings 4
C - Place disc and seat assembly between body halves 1.
D - Fit body screws 10 and nuts 11, tighten to recommended torques.
Valves DN 25 to DN 65 = 14 Nm, DN 80 to DN 150 = 19 Nm.
E - Fit notch plate 5 over the disc stem and locate lugs on notch plate in body.
F - Fit handle 6 to the disc stem so that the handle is parallel to the disc.
G - Fit the handle screw 8, spring washer 7 and plug 9.
H - As the valve is already installed in the pipeline use the position indicator on the valves bottom
stem to ensure the valve disc is in the desired position (flats are in line with disc).
I
- Cycle test the valve and inspect for leakage at plant start up.
6.8 Assembling the wafer style butterfly valve
(See appendix C)
A - Stretch seat 2 over bottom of disc stem (short end), then place seat on disc along the upper
stem and rotate disc 3 to the open position
B - Place upper and lower bearings 4
C - Place disc and seat assembly between body halves 1.
D - Fit body screws 16 and nuts 17, tighten to recommended torque’s.
Valves DN 25 to DN 65 = 14 Nm, DN 80 to DN 150 = 19 Nm.
E - Place flange seals 15.
F - Place the valve between the flanges 14.
G - Wind two of the inside nuts 13 back against the body halves 1.
H - Fit body screws 10 and nuts 11 and outer nuts 13.
I
- Fit notch plate 5 over the disc stem and locate lugs on notch plate in body.
J - Fit handle 6 to the disc stem so that the handle is parallel to the disc
K - Fit the handle screw 8, spring washer 7 and plug 9.
L - As the valve is already installed in the pipeline use the position indicator on the valves bottom
stem to ensure the valve disc is in the desired position (flats are in line with disc).
M - Cycle test the valve and inspect for leakage at plant start up.
6.6 Disassembling the wafer style butterfly valve
(See appendix C)
A - Locate handle 6 in closed position.
B - Loosen and remove bolts 10 and nuts 11.
C - Wind two of the inside nuts 13 back against the flanges 14 to clamp the flange between the
inner and outer nuts on each of the studs 12.
D - Loosen the outer nuts 13 on flange 14 (approx. 3-4 mm).
E - Wind the two remaining inside nuts 13 back against flange 14 to clamp and separate the flanges
with the jacking studs 12.
F - Remove the valve from between the flanges 14.
G - Remove flange seals 15.
H - Remove plug 9 from top of handle 6.
I
- Remove handle screw 8 and spring washer 7.
J - Remove handle 6 and notch plate 5.
K - Remove body screws 16 and nuts 17.
L - Separate body halves 1.
M - Remove disc stem 3 and seat 2 assembly.
Take care not to loose the upper and lower bearings 4 located on either side of the disc stem.
N - Remove upper and lower bearings 4.
O - Rotate disc 3 to the open position and stretch seat 2 over bottom of disc stem (short end), then
remove seat from disc along the upper stem.
