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INTRODUCTION
The seatless blow-off valve is a sliding plunger type,
opened and closed by means for a handwheel and non-rising
stem, and sealed against leakage by packing rings above and
below the ports. This valve is provided with heavy coil
compression springs under the yoke nuts. Designed to prevent
leaking when the valve is open, yoke nuts are screwed down
evenly and tightly placing compression on the springs and
the packing rings. Ample flow are is provided in hollow
plunger; absence of projections or pockets prevents
accumulation of scale and sediment that can impede flow and
shorten the life of the valve. Annular space in the body
permits pressure to surround the plunger, making the valve a
fully balanced unit easy to operate at high pressures. For
complete protection of the packing, the valve has a
long-stroke plunger so that packing is never exposed to the
mainstream flow. The gland and plunger have double inlet
ports to balance flow pressures.
OPERATION
When the valve is open (plunger raised), discharge
occurs through double ports in the lower gland and plunger.
The slotted plunger head slides on guides in the valve yoke,
preventing rotation of the plunger. A stop screw keeps the
lower gland in alignment. The yoke permits visual indication
of the position of the plunger within the valve body. Upon
closing, the shoulder of the plunger exerts a thrust force
compressing the packing rings above and below the port in
the body. A final hard turn of the handwheel gives
additional compression of the packing around the plunger,
insuring drop tight shut-off.
END CONNECTIONS
Flange dimensions per ANSI B 16.5
ACTUATION
Manual Handwheel only
HOW TO ORDER
Order by stating:
A. Size
B. Figure Number
C. Basic pressure rating
D. Connections (Flanged) |
