Parr Instrument A296VB2 User Manual

687M

1” NPT Bottom Drain Valve Model A296VB2

Operating & Maintenance Instructions

Description

The Parr Instrument Company A296VB2 Bottom
Drain Valve has an extended tip stem. In the
closed position, the stem of the valve is flush
with the inside bottom of the vessel so that
there is minimal dead space between the
bottom of the vessel and the shut off point
of the valve. In the fully open position, the
stem is retracted to open a clear passage from
the vessel. When the valve is re-closed, any
material in this passage will be pushed back
into the reactor by the rising stem.

CAUTION! If abrasive particles are
run through the valve, it is necessary
to flush the valve after use.

If the valve is leaking, it is a good indication
that the seal may be worn, has been damaged,
or abrasive particles are interfering. The valve
should be disassembled, inspected, cleaned as
required, and seals replaced.

Disassembly of the Bottom Drain Valve

Installation and Operation

This valve is designed to be installed in the
bottom of Parr cylinders that are machined
specifically for installation with minimal dead
space. Pipe thread sealant tape should be
applied to the valve body threads and then
installed turning clockwise into the cylinder. The
valve should be tightened sufficiently to seal
the pipe treads and bring the stem of the valve
approximately even with the inside bottom of
the cylinder.

The valve is opened by turning the handle
counterclockwise. Opening the valve will
progressively increase the passage for product
flow until the valve is at the fully open position.

The valve is closed by turning the handle
clockwise until the plunger contacts and
compresses seal 1.

1. Retract the plunger to the fully
open position by turning the handle
counterclockwise.

2. Remove the (3) 1/4-28 socket head cap
screws (SHCS) from the screw shaft retainer
using the 3/16 socket screw key furnished
with the BDV.

3. Loosen the (3) 1/4-28 socket head cap
screws that compress seal 2 with the
retainer using the 3/16 socket screw key
furnished with the BDV.

4. Pull the screw shaft retainer and plunger
assembly out of the valve body.

5. Remove the (3) standoffs.

6. Remove the (3) 1/4-28 socket head cap
screws and remove the retainer.

7. Using a pick, remove the compression rings
and seal 2.

Use the extension bar (661VBGA) provided with
the A296VB2 to open and close the valve.

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8. Using a pick, remove seal 1 from the valve
body.

Bottom Drain Valve Model A296VB2

Assembly of Bottom Drain Valve

1. Before assembly, all parts of the valve
should be clean and in good condition.

NOTE: Assembly of the valve is easier if it
is removed from service and oriented so
that the threads going into the cylinder face
downwards.

2. Apply generous amounts of lubrication
using a high temperature thread lubricant.
See the “Lubrication of the Bottom Drain
Valve” section in this manual.

3. Install a 511VB3FH silver or 511VB3FG gold
faced (depending on BDV material) seal 1
into the cavity in the valve body. The plunger
may be used to help with the installation.

4. Install the compression ring, next install
the PTFE seal 2, and then install the second
compression ring.

Lubrication of the Bottom Drain Valve

Lubrication of the straight threads should be
done with a nickel based high temperature
thread lubricant. If SD2520SC10 shoulder bolt
is removed, re-install into plunger with semi­permanent thread locker. Lubricate all other
internal and outer straight threads on the valve
body, retainers, and plunger.

The frequency of lubrication depends on the
amount of use the valve receives. If the valve
sits for a long period of time (one or more
months), it should be lubricated before use. If
the valve is used daily, then lubrication may be
required once a week.

Applications that include operating tempera­tures of 250 °C and above will require more
frequent lubrication of the valve threads.

5. Install the retainer and start the (3) 1/4-28
socket head cap screws.

6. Install the plunger assembly.

7. Tighten the retainer into valve body using
100 in-lbs torque on each of the (3) 1/4-28
socket head cap screws.

8. Install the (3) standoffs.

9. Install the (3) 1/4 flat socket head cap screws
with the plunger retracted away from seal 1.

10. Turn the handle clockwise until the plunger
contacts seal 1.

2

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