Val-Matic Cam-Centric Plug Valve - Manual (Page 2)

2
CAUTION: Do not use valve for line testing at
pressures higher than nameplate rating or
leakage and damage to valve may occur.
VAL-MATIC'S CAM-CENTRIC PLUG VALVE
OPERATION, MAINTENANCE AND INSTALLATION
INTRODUCTION
The Cam-Centric  Plug Valve has been designed to
give years of trouble-free operation. This manual will
provide you with the information to properly install and
maintain the valve to ensure a long service life. The
valve is an eccentric, resilient seated, quarter-turn plug
valve capable of handling many types of fluids
including fluids with suspended solids. The Size,
Cold Working Pressure (CWP), Actuator Rating, and
Model No. are stamped on the nameplate for
reference.
The "Cold Working Pressure" is the non-shock
pressure rating of the valve at 150
o F. The valve is not
intended as a block valve for line testing above the
valve rating. The “Actuator Rating” is the pressure that
was used to size the actuator for operating conditions
and may be less than the “Cold Working Pressure”.
Because the valve is eccentric, the valve may have a
different actuator rating for reverse and direct pressure.
If the valve is operated at pressures higher than the
actuator ratings, the valve may be difficult to operate or
leak.
RECEIVING AND STORAGE
Inspect valves upon receipt for damage in shipment.
Unload all valves carefully to the ground without
dropping. Do not lift valves with slings or chains
around the actuator or through the seat area.
Valves should remain crated, clean and dry until
installed to prevent weather-related damage. For long
term storage greater than six months, the valve must
remain open and the rubber surfaces of the plug
coated with a thin film of FDA approved grease such
as Dow Corning # 7. Do not expose plug to sunlight or
ozone for any extended period.
DESCRIPTION OF OPERATION
As shown in Figure 2, the valve consists of a body and
quarter-turn plug that is offset from the seat centerline.
FIGURE 1. PLUG VALVE WITH GEAR ACTUATOR
The eccentric offset causes the plug to lift and rotate
off the seat simultaneously to reduce seat friction and
wear during operation. Direct Pressure pushes the
plug into the seat and Reverse Pressure pushes the
plug away from the seat. The valve can be operated
with a direct nut, lever, or gear actuator. The gear
actuator as shown in Figure 1 requires multi-turn input
on a 2” square nut, handwheel, or chainwheel. The
valve can also be automated with power actuators
such as an electric motor or hydraulic cylinder.
FIGURE 2. PLUG VALVE TERMS