NIBCO Check Valve Automatic Stop F869B - Manual (Page 12)

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dashpot arrangement. It should be pointed out that the stop-check valve must always be in an
upright position with the handwheel on top of the valve. If this is not done there is no way that
the valve will work in its proper capacity.
Adjusting the F-869-B NIBCO Automatic Stop-Check Valve
The external control valve near the packing gland requires only a quarter turn to allow the disc
to descend or rise slowly or rapidly when the F-869-B valve is functioning as an automatic stop
and check valve (See sketch).
If slam or chatter exists in the line, the small control valve should be moved through 90° until the
noise no longer exists. At this point, the small packing nut on the control valve should be
tightened to assure the control valve does not move from its setting.
If a noise problem is still present and the steam delivery from the boiler is at a minimal operating
range, the delivery may have fallen below the range the valve was designed for. This may be
corrected by partially closing or “throttling” the valve by closing the handwheel. It is important to
remember the valve must be opened again when the boiler demand is increased. If the steam
delivery is changed to any great degree, the adjustment procedure may have to be repeated.
NOTE: 2-1/2” and 3” F-869-B stop-check valves do not have external disc control valves. The
disc control setting is made at the factory and permanently fixed.