M&H 4500, Руководство пользователя

Страница: 19 / 27

Page 19 of 27
SECTION 5
MAINTENANCE OF M&H BUTTERFLY VALVES
SECTION 5.1 – SAFETY
Before any maintenance or service work is conducted on an M&H BFV, whether above or below ground,
all potential safety issues should be considered.
For In-Plant BFVs, all work should be done in accordance with ASME Pressure Vessel Code and other
applicable standards.
For Vault Service BFVs, note that all entry into confined spaces, including trenches, may contain
hazardous atmospheres or other hazards and is regulated by OSHA* regulation CFR 1910.146, Confined
Spaces.
For Buried Service BFVs, at a minimum, prior to any excavation,

Obtain location of all underground utilities in the area to be excavated.

Obtain shut down of water, electricity, gas, or other utilities if there exist any potential to damage
these conduits.

Provide protection from trench wall cave in by proper sloping, shoring or other means in
accordance with OSHA* Regulation CFR 1926, Subpart P, Excavations.
NOTE: It is the responsibility of the servicing individual to make sure that all regulations and best
practices are followed for any service work. Individual states may have more stringent regulations.
Contact the appropriate state agency before any work is begun for additional information and any
potential permitting requirements.
SECTION 5.2 – VANE SEAT RING ADJUSTMENT – Sizes 3” thru 72”
1. If there is a small leak at a specific location around the circumference of the vane, this may be
corrected by adjusting the Vane Ring Bolts on the Vane.
2. Before attempting to adjust the bolts, open the valve fully and inspect the Vane Ring for any
mechanical damage to the rubber (a cut or tear or similar damage).
3. Once confirmed that the Vane Ring is in good condition, be sure to make sure that the seating area is
clean and free from any debris.
4. Move the vane to the fully closed position and confirm that the vane is level with the stainless-steel seat
in the valve body. NOTE: Make sure that the seating area has been lubricated with an NSF61 approved
lubricant. If the vane is not level with the seat is not level:
a If an M&H Traveling Nut Operator is being used, skip to Section 5.5 – Vane Level
Adjustment.
b If a third-party operator is being used, consult the Operator Manual for how to adjust the end
stops of the operator.
5. After Steps 2, 3 & 4 have been verified, if there is still water leaking in the seat area, determine
the location of the leakage.
a Using a Torque wrench (wrench should be in “in-lb” readings), determine the
approximate torque of the bolts around the leak.